Programs & Examples On #Mismatch

How to get parameter value for date/time column from empty MaskedTextBox

You're storing the .Text properties of the textboxes directly into the database, this doesn't work. The .Text properties are Strings (i.e. simple text) and not typed as DateTime instances. Do the conversion first, then it will work.

Do this for each date parameter:

Dim bookIssueDate As DateTime = DateTime.ParseExact( txtBookDateIssue.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture ) cmd.Parameters.Add( New OleDbParameter("@Date_Issue", bookIssueDate ) ) 

Note that this code will crash/fail if a user enters an invalid date, e.g. "64/48/9999", I suggest using DateTime.TryParse or DateTime.TryParseExact, but implementing that is an exercise for the reader.

Invalid hook call. Hooks can only be called inside of the body of a function component

I have just started using hooks and I got the above warning when i was calling useEffect inside a function:

Then I have to move the useEffect outside of the function as belows:

 const onChangeRetypePassword = async value => {
  await setRePassword(value);
//previously useEffect was here

//useEffect outside of func 

 useEffect(() => {
  if (password !== rePassword) {

}, [rePassword]);

Hope it will be helpful to someone !

How to style components using makeStyles and still have lifecycle methods in Material UI?

Another one solution can be used for class components - just override default MUI Theme properties with MuiThemeProvider. This will give more flexibility in comparison with other methods - you can use more than one MuiThemeProvider inside your parent component.

simple steps:

  1. import MuiThemeProvider to your class component
  2. import createMuiTheme to your class component
  3. create new theme
  4. wrap target MUI component you want to style with MuiThemeProvider and your custom theme

please, check this doc for more details:

import React from 'react';
import PropTypes from 'prop-types';
import Button from '@material-ui/core/Button';

import { MuiThemeProvider } from '@material-ui/core/styles';
import { createMuiTheme } from '@material-ui/core/styles';

const InputTheme = createMuiTheme({
    overrides: {
        root: {
            background: 'linear-gradient(45deg, #FE6B8B 30%, #FF8E53 90%)',
            border: 0,
            borderRadius: 3,
            boxShadow: '0 3px 5px 2px rgba(255, 105, 135, .3)',
            color: 'white',
            height: 48,
            padding: '0 30px',

class HigherOrderComponent extends React.Component {

        const { classes } = this.props;
        return (
            <MuiThemeProvider theme={InputTheme}>
                <Button className={classes.root}>Higher-order component</Button>

HigherOrderComponent.propTypes = {
    classes: PropTypes.object.isRequired,

export default HigherOrderComponent;

React Native version mismatch

For Android developers who couldn't get it fixed by just closing and rebuilding, Manually uninstall the app on the emulator/device.

NVIDIA NVML Driver/library version mismatch

So I was having this problem, none of the other remedies worked. The error message was opaque, but checking dmesg was key:

[   10.118255] NVRM: API mismatch: the client has the version 410.79, but
           NVRM: this kernel module has the version 384.130.  Please
           NVRM: make sure that this kernel module and all NVIDIA driver
           NVRM: components have the same version.

However I had completely removed the 384 version, and removed any remaining kernel drivers nvidia-384*. But even after reboot, I was still getting this. Seeing this meant that the kernel was still compiled to reference 384, but was only finding 410. So I recompiled my kernel:

# uname -a # find the kernel it's using
Linux blah 4.13.0-43-generic #48~16.04.1-Ubuntu SMP Thu May 17 12:56:46 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
# update-initramfs -c -k 4.13.0-43-generic #recompile it
# reboot

And then it worked.

After removing 384, I still had 384 files in: /var/lib/dkms/nvidia-XXX/XXX.YY/4.13.0-43-generic/x86_64/module /lib/modules/4.13.0-43-generic/kernel/drivers

I recommend using the locate command (not installed by default) rather than searching the filesystem every time.

Caused by: org.flywaydb.core.api.FlywayException: Validate failed. Migration Checksum mismatch for migration 2

simple solution will be change spring.datasource.url=jdbc:h2:file:~/dasboot in to new file name like : spring.datasource.url=jdbc:h2:file:~/dasboots

Resource blocked due to MIME type mismatch (X-Content-Type-Options: nosniff)

This can be fixed by changing your URL, example bad:
Content-Type: text/plain; charset=utf-8

Example good:
content-type: application/javascript;charset=utf-8 is a caching proxy service for github. You can also go there and interactively derive a corresponding URL for your original URL. See its FAQ

How to get Tensorflow tensor dimensions (shape) as int values?

Another way to solve this is like this:


This will return the int value of the Dimension object.

FCM getting MismatchSenderId

I have noticed that when a device id is created in GCM you cannot send push messages through FCM using the new server key, you have to use the old API-key.

TokenMismatchException in VerifyCsrfToken.php Line 67

I was about to start pulling out my hair!

Please check your session cookie domain in session.php config. There is a domain option that has to match your environment and it's good practice to have this configurable with you .env file for development.

'domain' => env('COOKIE_DOMAIN', ''),

Laravel csrf token mismatch for ajax POST Request

Add an id to the meta element that holds the token

<meta name="csrf-token" id="csrf-token" content="{{ csrf_token() }}">

And then you can get it in your Javascript

  url : "your_url",
  data : {
    "_token": $('#csrf-token')[0].content  //pass the CSRF_TOKEN()

EDIT: Easier way without changing the meta line.

data : { 
    _token: "{{ csrf_token() }}" 


data : { 
    _token: @json(csrf_token()), 

Thanks to @martin-hartmann

Adding form action in html in laravel

Your form is also missing '{{csrf_field()}}'

How to convert interface{} to string?

You need to add type assertion .(string). It is necessary because the map is of type map[string]interface{}:

host := arguments["<host>"].(string) + ":" + arguments["<port>"].(string)

Latest version of Docopt returns Opts object that has methods for conversion:

host, err := arguments.String("<host>")
port, err := arguments.String("<port>")
host_port := host + ":" + port

How to delete specific columns with VBA?

To answer the question How to delete specific columns in vba for excel. I use Array as below.

sub del_col()

dim myarray as variant
dim i as integer

myarray = Array(10, 9, 8)'Descending to Ascending
For i = LBound(myarray) To UBound(myarray)
Next i

end sub

How to pass an array to a function in VBA?

Your function worked for me after changing its declaration to this ...

Function processArr(Arr As Variant) As String

You could also consider a ParamArray like this ...

Function processArr(ParamArray Arr() As Variant) As String
    'Dim N As Variant
    Dim N As Long
    Dim finalStr As String
    For N = LBound(Arr) To UBound(Arr)
        finalStr = finalStr & Arr(N)
    Next N
    processArr = finalStr
End Function

And then call the function like this ...

processArr("foo", "bar")

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

Personally, I prefer changing the method signature to:

public ResponseEntity<?>

This gives the advantage of possibly returning an error message as single item for services which, when ok, return a list of items.

When returning I don't use any type (which is unused in this case anyway):

return new ResponseEntity<>(entities, HttpStatus.OK);

SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch

I got a MD5 hash with different results for both key and certificate.

This says it all. You have a mismatch between your key and certificate.

The modulus should match. Make sure you have correct key.

Getting "The remote certificate is invalid according to the validation procedure" when SMTP server has a valid certificate

The answer I have finally found is that the SMTP service on the server is not using the same certificate as https.

The diagnostic steps I had read here make the assumption they use the same certificate and every time I've tried this in the past they have done and the diagnostic steps are exactly what I've done to solve the problem several times.

In this case those steps didn't work because the certificates in use were different, and the possibility of this is something I had never come across.

The solution is either to export the actual certificate from the server and then install it as a trusted certificate on my machine, or to get a different valid/trusted certificate for the SMTP service on the server. That is currently with our IT department who administer the servers to decide which they want to do.

Failed to load resource: net::ERR_CONTENT_LENGTH_MISMATCH

This can be caused by a full disk (Ubuntu/Nginx).

My situation:

Selecting specific rows and columns from NumPy array

As Toan suggests, a simple hack would be to just select the rows first, and then select the columns over that.

>>> a[[0,1,3], :]            # Returns the rows you want
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [12, 13, 14, 15]])
>>> a[[0,1,3], :][:, [0,2]]  # Selects the columns you want as well
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

[Edit] The built-in method: np.ix_

I recently discovered that numpy gives you an in-built one-liner to doing exactly what @Jaime suggested, but without having to use broadcasting syntax (which suffers from lack of readability). From the docs:

Using ix_ one can quickly construct index arrays that will index the cross product. a[np.ix_([1,3],[2,5])] returns the array [[a[1,2] a[1,5]], [a[3,2] a[3,5]]].

So you use it like this:

>>> a = np.arange(20).reshape((5,4))
>>> a[np.ix_([0,1,3], [0,2])]
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

And the way it works is that it takes care of aligning arrays the way Jaime suggested, so that broadcasting happens properly:

>>> np.ix_([0,1,3], [0,2])
        [3]]), array([[0, 2]]))

Also, as MikeC says in a comment, np.ix_ has the advantage of returning a view, which my first (pre-edit) answer did not. This means you can now assign to the indexed array:

>>> a[np.ix_([0,1,3], [0,2])] = -1
>>> a    
array([[-1,  1, -1,  3],
       [-1,  5, -1,  7],
       [ 8,  9, 10, 11],
       [-1, 13, -1, 15],
       [16, 17, 18, 19]])

Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies. Manifest definition does not match the assembly reference

Easy steps. (1)Run "update-package Newtonsoft.Json -reinstall" in package manager.

(2)Delete you bin by enabling viewing the hidden files and deleting the bin folder.

(3)Close your visual studio and re-open it.

(4) Now run your project again. I believe it should be ok

How to fill color in a cell in VBA?

Non VBA Solution:

Use Conditional Formatting rule with formula: =ISNA(A1) (to highlight cells with all errors - not only #N/A, use =ISERROR(A1))

enter image description here

VBA Solution:

Your code loops through 50 mln cells. To reduce number of cells, I use .SpecialCells(xlCellTypeFormulas, 16) and .SpecialCells(xlCellTypeConstants, 16)to return only cells with errors (note, I'm using If cell.Text = "#N/A" Then)

Sub ColorCells()
    Dim Data As Range, Data2 As Range, cell As Range
    Dim currentsheet As Worksheet

    Set currentsheet = ActiveWorkbook.Sheets("Comparison")

    With currentsheet.Range("A2:AW" & Rows.Count)
        .Interior.Color = xlNone
        On Error Resume Next
        'select only cells with errors
        Set Data = .SpecialCells(xlCellTypeFormulas, 16)
        Set Data2 = .SpecialCells(xlCellTypeConstants, 16)
        On Error GoTo 0
    End With

    If Not Data2 Is Nothing Then
        If Not Data Is Nothing Then
            Set Data = Union(Data, Data2)
            Set Data = Data2
        End If
    End If

    If Not Data Is Nothing Then
        For Each cell In Data
            If cell.Text = "#N/A" Then
               cell.Interior.ColorIndex = 4
            End If
    End If
End Sub

Note, to highlight cells witn any error (not only "#N/A"), replace following code

If Not Data Is Nothing Then
   For Each cell In Data
       If cell.Text = "#N/A" Then
          cell.Interior.ColorIndex = 3
       End If
End If


If Not Data Is Nothing Then Data.Interior.ColorIndex = 3

UPD: (how to add CF rule through VBA)

Sub test()
    With ActiveWorkbook.Sheets("Comparison").Range("A2:AW" & Rows.Count).FormatConditions
        .Add Type:=xlExpression, Formula1:="=ISNA(A1)"
        .Item(1).Interior.ColorIndex = 3
    End With
End Sub

Transaction count after EXECUTE indicates a mismatching number of BEGIN and COMMIT statements. Previous count = 1, current count = 0

If you have a TRY/CATCH block then the likely cause is that you are catching a transaction abort exception and continue. In the CATCH block you must always check the XACT_STATE() and handle appropriate aborted and uncommitable (doomed) transactions. If your caller starts a transaction and the calee hits, say, a deadlock (which aborted the transaction), how is the callee going to communicate to the caller that the transaction was aborted and it should not continue with 'business as usual'? The only feasible way is to re-raise an exception, forcing the caller to handle the situation. If you silently swallow an aborted transaction and the caller continues assuming is still in the original transaction, only mayhem can ensure (and the error you get is the way the engine tries to protect itself).

I recommend you go over Exception handling and nested transactions which shows a pattern that can be used with nested transactions and exceptions:

create procedure [usp_my_procedure_name]
    set nocount on;
    declare @trancount int;
    set @trancount = @@trancount;
    begin try
        if @trancount = 0
            begin transaction
            save transaction usp_my_procedure_name;

        -- Do the actual work here

        if @trancount = 0
    end try
    begin catch
        declare @error int, @message varchar(4000), @xstate int;
        select @error = ERROR_NUMBER(), @message = ERROR_MESSAGE(), @xstate = XACT_STATE();
        if @xstate = -1
        if @xstate = 1 and @trancount = 0
        if @xstate = 1 and @trancount > 0
            rollback transaction usp_my_procedure_name;

        raiserror ('usp_my_procedure_name: %d: %s', 16, 1, @error, @message) ;
    end catch

how to set mongod --dbpath

You could also configure mongod to run on start up so that it is automatically running on start up and the dbpath is set upon configuration. To do this try:

mongod --smallfiles --config /etc/mongod.conf

The --smallfiles tag is there in case you get an error with size. It is, of course, optional. Doing this should solve your problem while also automating your mongodb setup.

How to pass ArrayList<CustomeObject> from one activity to another?

you need implements Parcelable in your ContactBean class, I put one example for you:

public class ContactClass implements Parcelable {

private String id;
private String photo;
private String firstname;
private String lastname;

public ContactClass()


private ContactClass(Parcel in) {
    firstname = in.readString();
    lastname = in.readString();
    photo = in.readString();
    id = in.readString();


public int describeContents() {
    // TODO Auto-generated method stub
    return 0;

public void writeToParcel(Parcel dest, int flags) {



 public static final Parcelable.Creator<ContactClass> CREATOR = new Parcelable.Creator<ContactClass>() {
        public ContactClass createFromParcel(Parcel in) {
            return new ContactClass(in);

        public ContactClass[] newArray(int size) {
            return new ContactClass[size];


   // all get , set method 

and this get and set for your code:

Intent intent = new Intent(this,DisplayContact.class);
intent.putExtra("Contact_list", ContactLis);

second class:

ArrayList<ContactClass> myList = getIntent().getParcelableExtra("Contact_list");

Convert Text to Date?

Blast from the past but I think I found an easy answer to this. The following worked for me. I think it's the equivalent of selecting the cell hitting F2 and then hitting enter, which makes Excel recognize the text as a date.

Selection.Value = Selection.Value

How can I find out the total physical memory (RAM) of my linux box suitable to be parsed by a shell script?

free -h | awk '/Mem\:/ { print $2 }' 

This will provide you with the total memory in your system in human readable format and automatically scale to the appropriate unit ( e.g. bytes, KB, MB, or GB).

Is it possible to use global variables in Rust?

You can use static variables fairly easily as long as they are thread-local.

The downside is that the object will not be visible to other threads your program might spawn. The upside is that unlike truly global state, it is entirely safe and is not a pain to use - true global state is a massive pain in any language. Here's an example:

extern mod sqlite;

use std::cell::RefCell;

thread_local!(static ODB: RefCell<sqlite::database::Database> = RefCell::new(sqlite::open("test.db"));

fn main() {
    ODB.with(|odb_cell| {
        let odb = odb_cell.borrow_mut();
        // code that uses odb goes here

Here we create a thread-local static variable and then use it in a function. Note that it is static and immutable; this means that the address at which it resides is immutable, but thanks to RefCell the value itself will be mutable.

Unlike regular static, in thread-local!(static ...) you can create pretty much arbitrary objects, including those that require heap allocations for initialization such as Vec, HashMap and others.

If you cannot initialize the value right away, e.g. it depends on user input, you may also have to throw Option in there, in which case accessing it gets a bit unwieldy:

extern mod sqlite;

use std::cell::RefCell;

thread_local!(static ODB: RefCell<Option<sqlite::database::Database>> = RefCell::New(None));

fn main() {
    ODB.with(|odb_cell| {
        // assumes the value has already been initialized, panics otherwise
        let odb = odb_cell.borrow_mut().as_mut().unwrap();
        // code that uses odb goes here

error LNK2038: mismatch detected for '_MSC_VER': value '1600' doesn't match value '1700' in CppFile1.obj

for each project in your solution make sure that

Properties > Config. Properties > General > Platform Toolset

is one for all of them, v100 for visual studio 2010, v110 for visual studio 2012

you also may be working on v100 from visual studio 2012

Could not load file or assembly 'System.Web.Http 4.0.0 after update from 2012 to 2013

As others have said just reinstall the MVC package to your web project using nuget, but be sure to add the MVC package to any projects depending on the web project, such as unit tests. If you build each included project individually, you will see witch ones require the update.

Cannot overwrite model once compiled Mongoose

I know there is an accepted solution but I feel that the current solution results in a lot of boilerplate just so that you can test Models. My solution is essentially to take you model and place it inside of a function resulting in returning the new Model if the Model has not been registered but returning the existing Model if it has.

function getDemo () {
  // Create your Schema
  const DemoSchema = new mongoose.Schema({
    name: String,
    email: String
  }, {
    collection: 'demo'
  // Check to see if the model has been registered with mongoose
  // if it exists return that model
  if (mongoose.models && mongoose.models.Demo) return mongoose.models.Demo
  // if no current model exists register and return new model
  return mongoose.model('Demo', DemoSchema)

export const Demo = getDemo()

Opening and closing connections all over the place is frustrating and does not compress well.

This way if I were to require the model two different places or more specifically in my tests I would not get errors and all the correct information is being returned.

Excel Validation Drop Down list using VBA

You are defining your array as xlValidateList(), so when you try to assign the type, it gets confused as to what you are trying to assign to the type.

Instead, try this:

Dim MyList(5) As String
MyList(0) = 1
MyList(1) = 2
MyList(2) = 3
MyList(3) = 4
MyList(4) = 5
MyList(5) = 6

With Range("A1").Validation
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
         Operator:=xlBetween, Formula1:=Join(MyList, ",")
End With

Syntax error "syntax error, unexpected end-of-input, expecting keyword_end (SyntaxError)"

It seems that you have a bunch of describes that never have ends keywords, starting with describe "when email format is invalid" do until describe "when email address is already taken" do

Put an end on those guys and you're probably done =)

Android Studio - local path doesn't exist

For me uninstalling the app from the device works. :)

Set Matplotlib colorbar size to match graph

I appreciate all the answers above. However, like some answers and comments pointed out, the axes_grid1 module cannot address GeoAxes, whereas adjusting fraction, pad, shrink, and other similar parameters cannot necessarily give the very precise order, which really bothers me. I believe that giving the colorbar its own axes might be a better solution to address all the issues that have been mentioned.


import matplotlib.pyplot as plt
import numpy as np

ax = plt.axes()
im = ax.imshow(np.arange(100).reshape((10,10)))

# Create an axes for colorbar. The position of the axes is calculated based on the position of ax.
# You can change 0.01 to adjust the distance between the main image and the colorbar.
# You can change 0.02 to adjust the width of the colorbar.
# This practice is universal for both subplots and GeoAxes.

cax = fig.add_axes([ax.get_position().x1+0.01,ax.get_position().y0,0.02,ax.get_position().height])
plt.colorbar(im, cax=cax) # Similar to fig.colorbar(im, cax = cax)


enter image description here

Later on, I find matplotlib.pyplot.colorbar official documentation also gives ax option, which are existing axes that will provide room for the colorbar. Therefore, it is useful for multiple subplots, see following.


fig, ax = plt.subplots(2,1,figsize=(12,8)) # Caution, figsize will also influence positions.
im1 = ax[0].imshow(np.arange(100).reshape((10,10)), vmin = -100, vmax =100)
im2 = ax[1].imshow(np.arange(-100,0).reshape((10,10)), vmin = -100, vmax =100)
fig.colorbar(im1, ax=ax)


enter image description here

Again, you can also achieve similar effects by specifying cax, a more accurate way from my perspective.


fig, ax = plt.subplots(2,1,figsize=(12,8))
im1 = ax[0].imshow(np.arange(100).reshape((10,10)), vmin = -100, vmax =100)
im2 = ax[1].imshow(np.arange(-100,0).reshape((10,10)), vmin = -100, vmax =100)
cax = fig.add_axes([ax[1].get_position().x1-0.25,ax[1].get_position().y0,0.02,ax[0].get_position().y1-ax[1].get_position().y0])
fig.colorbar(im1, cax=cax)


enter image description here

Which JDK version (Language Level) is required for Android Studio?

Normally, I would go with what the documentation says but if the instructor explicitly said to stick with JDK 6, I'd use JDK 6 because you would want your development environment to be as close as possible to the instructors. It would suck if you ran into an issue and having the thought in the back of your head that maybe it's because you're on JDK 7 that you're having the issue. Btw, I haven't touched Android recently but I personally never ran into issues when I was on JDK 7 but mind you, I only code Android apps casually.

How to read strings from a Scanner in a Java console application?


System.out.println("Enter EmployeeName:");


System.out.println("Enter EmployeeName:");

This is because next() grabs only the next token, and the space acts as a delimiter between the tokens. By this, I mean that the scanner reads the input: "firstname lastname" as two separate tokens. So in your example, ename would be set to firstname and the scanner is attempting to set the supervisorId to lastname

Using jQuery's ajax method to retrieve images as a blob

If you need to handle error messages using jQuery.AJAX you will need to modify the xhr function so the responseType is not being modified when an error happens.

So you will have to modify the responseType to "blob" only if it is a successful call:

    xhr: function() {
        var xhr = new XMLHttpRequest();
        xhr.onreadystatechange = function() {
            if (xhr.readyState == 2) {
                if (xhr.status == 200) {
                    xhr.responseType = "blob";
                } else {
                    xhr.responseType = "text";
        return xhr;
    error: function(xhr, textStatus, errorThrown) {
        // Here you are able now to access to the property "responseText"
        // as you have the type set to "text" instead of "blob".
    success: function(data) {
        console.log(data); // Here is "blob" type


If you debug and place a breakpoint at the point right after setting the xhr.responseType to "blob" you can note that if you try to get the value for responseText you will get the following message:

The value is only accessible if the object's 'responseType' is '' or 'text' (was 'blob').

Cannot Resolve Collation Conflict

The thing about collations is that although the database has its own collation, every table, and every column can have its own collation. If not specified it takes the default of its parent object, but can be different.

When you change collation of the database, it will be the new default for all new tables and columns, but it doesn't change the collation of existing objects inside the database. You have to go and change manually the collation of every table and column.

Luckily there are scripts available on the internet that can do the job. I am not going to recommend any as I haven't tried them but here are few links:

Update Collation of all fields in database on the fly

If you need to have different collation on two objects or can't change collations - you can still JOIN between them using COLLATE command, and choosing the collation you want for join.

SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE Latin1_General_CI_AS 

or using default database collation:


How to multiply duration by integer?

It's nice that Go has a Duration type -- having explicitly defined units can prevent real-world problems.

And because of Go's strict type rules, you can't multiply a Duration by an integer -- you must use a cast in order to multiply common types.

MultiplyDuration Hide semantically invalid duration math behind a function
func MultiplyDuration(factor int64, d time.Duration) time.Duration {
    return time.Duration(factor) * d        // method 1 -- multiply in 'Duration'
 // return time.Duration(factor * int64(d)) // method 2 -- multiply in 'int64'

The official documentation demonstrates using method #1:

To convert an integer number of units to a Duration, multiply:

seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s

But, of course, multiplying a duration by a duration should not produce a duration -- that's nonsensical on the face of it. Case in point, 5 milliseconds times 5 milliseconds produces 6h56m40s. Attempting to square 5 seconds results in an overflow (and won't even compile if done with constants).

By the way, the int64 representation of Duration in nanoseconds "limits the largest representable duration to approximately 290 years", and this indicates that Duration, like int64, is treated as a signed value: (1<<(64-1))/(1e9*60*60*24*365.25) ~= 292, and that's exactly how it is implemented:

// A Duration represents the elapsed time between two instants
// as an int64 nanosecond count. The representation limits the
// largest representable duration to approximately 290 years.
type Duration int64

So, because we know that the underlying representation of Duration is an int64, performing the cast between int64 and Duration is a sensible NO-OP -- required only to satisfy language rules about mixing types, and it has no effect on the subsequent multiplication operation.

If you don't like the the casting for reasons of purity, bury it in a function call as I have shown above.

Delete all duplicate rows Excel vba

There's a RemoveDuplicates method that you could use:

Sub DeleteRows()

    With ActiveSheet
        Set Rng = Range("A1", Range("B1").End(xlDown))
        Rng.RemoveDuplicates Columns:=Array(1, 2), Header:=xlYes
    End With

End Sub

ValueError: shape mismatch: objects cannot be broadcast to a single shape

This particular error implies that one of the variables being used in the arithmetic on the line has a shape incompatible with another on the same line (i.e., both different and non-scalar). Since n and the output of np.add.reduce() are both scalars, this implies that the problem lies with xm and ym, the two of which are simply your x and y inputs minus their respective means.

Based on this, my guess is that your x and y inputs have different shapes from one another, making them incompatible for element-wise multiplication.

** Technically, it's not that variables on the same line have incompatible shapes. The only problem is when two variables being added, multiplied, etc., have incompatible shapes, whether the variables are temporary (e.g., function output) or not. Two variables with different shapes on the same line are fine as long as something else corrects the issue before the mathematical expression is evaluated.

ByRef argument type mismatch in Excel VBA

Something is wrong with that string try like this:

Worksheets(data_sheet).Range("C2").Value = ProcessString(CStr(last_name))

How to split a string and assign it to variables

package main

import (

func main() {
    strs := strings.Split("", ":")
    ip := strs[0]
    port := strs[1]
    fmt.Println(ip, port)

Here is the definition for strings.Split

// Split slices s into all substrings separated by sep and returns a slice of
// the substrings between those separators.
// If s does not contain sep and sep is not empty, Split returns a
// slice of length 1 whose only element is s.
// If sep is empty, Split splits after each UTF-8 sequence. If both s
// and sep are empty, Split returns an empty slice.
// It is equivalent to SplitN with a count of -1.
func Split(s, sep string) []string { return genSplit(s, sep, 0, -1) }

Jar mismatch! Fix your dependencies

Don't Include the android-support-v4 in the library , instead you can add it to your project as an external jar using build path menu > add external jar

Sometimes you have to clean your project.

Convert string to JSON array

If having following JSON from web service, Json Array as a response :

 0:  {
 id: 2
 name: "a561137"
 password: "test"
 firstName: "abhishek"
 lastName: "ringsia"
 organization: "bbb"
1:  {
 id: 3
 name: "a561023"
 password: "hello"
 firstName: "hello"
  lastName: "hello"
  organization: "hello"
 2:  {
  id: 4
  name: "a541234"
  password: "hello"
  firstName: "hello"
  lastName: "hello"
  organization: "hello"

have To Accept it first as a Json Array ,then while reading its Object have to use Object Mapper.readValue ,because Json Object Still in String .

      List<User> list = new ArrayList<User>();
      JSONArray jsonArr = new JSONArray(response);

      for (int i = 0; i < jsonArr.length(); i++) {
        JSONObject jsonObj = jsonArr.getJSONObject(i);
         ObjectMapper mapper = new ObjectMapper();
        User usr = mapper.readValue(jsonObj.toString(), User.class);      

    } is correct function ,if u use mapper.convert(param,param) . It will give u error .

Content Type application/soap+xml; charset=utf-8 was not supported by service

My case had a different solution. The client was using basichttpsbinding[1] and the service was using wshttpbinding.

I resolved the problem by changing the server binding to basichttpsbinding. Also, i had to set target framework to 4.5 by adding:

    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5"/>

[1] the comunication was over https.

How do I read a file line by line in VB Script?

When in doubt, read the documentation:

filename = "C:\Temp\vblist.txt"

Set fso = CreateObject("Scripting.FileSystemObject")
Set f = fso.OpenTextFile(filename)

Do Until f.AtEndOfStream
  WScript.Echo f.ReadLine


Start an activity from a fragment

I use this in my fragment.

Button btn1 = (Button) thisLayout

    btn1.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent intent = new Intent(getActivity(), otherActivity.class);
            ((MainActivity) getActivity()).startActivity(intent);


    return thisLayout;

Iterator over HashMap in Java

Map<String, Car> carMap = new HashMap<String, Car>(16, (float) 0.75);

// there is no iterator for Maps, but there are methods to do this.

        Set<String> keys = carMap.keySet(); // returns a set containing all the keys
        for(String c : keys)


        Collection<Car> values = carMap.values(); // returns a Collection with all the objects
        for(Car c : values)
        /*keySet and the values methods serve as “views” into the Map.
          The elements in the set and collection are merely references to the entries in the map, 
          so any changes made to the elements in the set or collection are reflected in the map, and vice versa.*/

        /*The entrySet method returns a Set of Map.Entry objects. 
          Entry is an inner interface in the Map interface.
          Two of the methods specified by Map.Entry are getKey and getValue.
          The getKey method returns the key and getValue returns the value.*/

        Set<Map.Entry<String, Car>> cars = carMap.entrySet(); 
        for(Map.Entry<String, Car> e : cars)
            System.out.println("Keys = " + e.getKey());
            System.out.println("Values = " + e.getValue().getDiscription() + "\n");


@Value annotation type casting to Integer from String

Assuming you have a properties file on your classpath that contains


I tried inside a @Controller

public class MyController {     
    private Integer pingFrequency;

With my servlet context containing :

<context:property-placeholder location="" />

It worked perfectly.

So either your property is not an integer type, you don't have the property placeholder configured correctly, or you are using the wrong property key.

I tried running with an invalid property value, 4123;. The exception I got is

java.lang.NumberFormatException: For input string: "4123;"

which makes me think the value of your property is


Mismatched anonymous define() module

I had this error because I included the requirejs file along with other librairies included directly in a script tag. Those librairies (like lodash) used a define function that was conflicting with require's define. The requirejs file was loading asynchronously so I suspect that the require's define was defined after the other libraries define, hence the conflict.

To get rid of the error, include all your other js files by using requirejs.

How to convert list data into json in java

i wrote my own function to return list of object for populate combo box :

public static String getJSONList(java.util.List<Object> list,String kelas,String name, String label) {
        try {
            Object[] args={};
            Class cl = Class.forName(kelas);
            Method getName = cl.getMethod(name, null);
            Method getLabel = cl.getMethod(label, null);
            String json="[";
            for (int i = 0; i < list.size(); i++) {
            Object o = list.get(i);
            //System.out.println("Object = " + i+" -> "+o.getNumber());
            return json;
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(JSONHelper.class.getName()).log(Level.SEVERE, null, ex);
        } catch (Exception ex) {
            System.out.println("Error in get JSON List");
        return "";

and call it from anywhere like :

String toreturn=JSONHelper.getJSONList(list, "com.bean.Contact", "getContactID", "getNumber");

What is the reason and how to avoid the [FIN, ACK] , [RST] and [RST, ACK]

Here is a rough explanation of the concepts.

[ACK] is the acknowledgement that the previously sent data packet was received.

[FIN] is sent by a host when it wants to terminate the connection; the TCP protocol requires both endpoints to send the termination request (i.e. FIN).

So, suppose

  • host A sends a data packet to host B
  • and then host B wants to close the connection.
  • Host B (depending on timing) can respond with [FIN,ACK] indicating that it received the sent packet and wants to close the session.
  • Host A should then respond with a [FIN,ACK] indicating that it received the termination request (the ACK part) and that it too will close the connection (the FIN part).

However, if host A wants to close the session after sending the packet, it would only send a [FIN] packet (nothing to acknowledge) but host B would respond with [FIN,ACK] (acknowledges the request and responds with FIN).

Finally, some TCP stacks perform half-duplex termination, meaning that they can send [RST] instead of the usual [FIN,ACK]. This happens when the host actively closes the session without processing all the data that was sent to it. Linux is one operating system which does just this.

You can find a more detailed and comprehensive explanation here.

Mismatch Detected for 'RuntimeLibrary'

Issue can be solved by adding CRT of msvcrtd.lib in the linker library. Because cryptlib.lib used CRT version of debug.

How to specify function types for void (not Void) methods in Java8?

I feel you should be using the Consumer interface instead of Function<T, R>.

A Consumer is basically a functional interface designed to accept a value and return nothing (i.e void)

In your case, you can create a consumer elsewhere in your code like this:

Consumer<Integer> myFunction = x -> {
    System.out.println("processing value: " + x);    
    .... do some more things with "x" which returns nothing...

Then you can replace your myForEach code with below snippet:

public static void myForEach(List<Integer> list, Consumer<Integer> myFunction) 

You treat myFunction as a first-class object.

cannot convert data (type interface {}) to type string: need type assertion

As asked for by @??s???? an explanation can be found at Related explanations can be found at and at Here is @Yuanbo's answer in full.

package main

import "fmt"

func main() {
    var data interface{} = 2
    str := fmt.Sprint(data)

Why am I getting InputMismatchException?

I encountered the same problem. Strange, but the reason was that the object Scanner interprets fractions depending on localization of system. If the current localization uses a comma to separate parts of the fractions, the fraction with the dot will turn into type String. Hence the error ...

Set custom HTML5 required field validation message

Man, I never have done that in HTML 5 but I'll try. Take a look on this fiddle.

I have used some jQuery, HTML5 native events and properties and a custom attribute on input tag(this may cause problem if you try to validade your code). I didn't tested in all browsers but I think it may work.

This is the field validation JavaScript code with jQuery:

    $('input[required], input[required="required"]').each(function(i, e)
        e.oninput = function(el)

            if ( == "email")
                if (
          "E-mail format invalid.");

                    if (
               "An e-mail address must be given.");

        e.oninvalid = function(el)
  ! ? e.attributes.requiredmessage.value : "");

Nice. Here is the simple form html:

<form method="post" action="" id="validation">
    <input type="text" id="name" name="name" required="required" requiredmessage="Name is required." />
    <input type="email" id="email" name="email" required="required" requiredmessage="A valid E-mail address is required." pattern="^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9]+$" />

    <input type="submit" value="Send it!" />

The attribute requiredmessage is the custom attribute I talked about. You can set your message for each required field there cause jQuery will get from it when it will display the error message. You don't have to set each field right on JavaScript, jQuery does it for you. That regex seems to be fine(at least it block your [email protected]! haha)

As you can see on fiddle, I make an extra validation of submit form event(this goes on document.ready too):

$("#validation").on("submit", function(e)
    for (var i = 0; i <; i++)
        if (![i].validity.valid)
            return false;

I hope this works or helps you in anyway.

Difference between number and integer datatype in oracle dictionary views

This is what I got from oracle documentation, but it is for oracle 10g release 2:

When you define a NUMBER variable, you can specify its precision (p) and scale (s) so that it is sufficiently, but not unnecessarily, large. Precision is the number of significant digits. Scale can be positive or negative. Positive scale identifies the number of digits to the right of the decimal point; negative scale identifies the number of digits to the left of the decimal point that can be rounded up or down.

The NUMBER data type is supported by Oracle Database standard libraries and operates the same way as it does in SQL. It is used for dimensions and surrogates when a text or INTEGER data type is not appropriate. It is typically assigned to variables that are not used for calculations (like forecasts and aggregations), and it is used for variables that must match the rounding behavior of the database or require a high degree of precision. When deciding whether to assign the NUMBER data type to a variable, keep the following facts in mind in order to maximize performance:

  • Analytic workspace calculations on NUMBER variables is slower than other numerical data types because NUMBER values are calculated in software (for accuracy) rather than in hardware (for speed).
  • When data is fetched from an analytic workspace to a relational column that has the NUMBER data type, performance is best when the data already has the NUMBER data type in the analytic workspace because a conversion step is not required.


From Language DDL & UDF of Hive

NVL(value, default value) 

Returns default value if value is null else returns value

Case insensitive access for generic dictionary

There's no way to specify a StringComparer at the point where you try to get a value. If you think about it, "foo".GetHashCode() and "FOO".GetHashCode() are totally different so there's no reasonable way you could implement a case-insensitive get on a case-sensitive hash map.

You can, however, create a case-insensitive dictionary in the first place using:-

var comparer = StringComparer.OrdinalIgnoreCase;
var caseInsensitiveDictionary = new Dictionary<string, int>(comparer);

Or create a new case-insensitive dictionary with the contents of an existing case-sensitive dictionary (if you're sure there are no case collisions):-

var oldDictionary = ...;
var comparer = StringComparer.OrdinalIgnoreCase;
var newDictionary = new Dictionary<string, int>(oldDictionary, comparer);

This new dictionary then uses the GetHashCode() implementation on StringComparer.OrdinalIgnoreCase so comparer.GetHashCode("foo") and comparer.GetHashcode("FOO") give you the same value.

Alternately, if there are only a few elements in the dictionary, and/or you only need to lookup once or twice, you can treat the original dictionary as an IEnumerable<KeyValuePair<TKey, TValue>> and just iterate over it:-

var myKey = ...;
var myDictionary = ...;
var comparer = StringComparer.OrdinalIgnoreCase;
var value = myDictionary.FirstOrDefault(x => String.Equals(x.Key, myKey, comparer)).Value;

Or if you prefer, without the LINQ:-

var myKey = ...;
var myDictionary = ...;
var comparer = StringComparer.OrdinalIgnoreCase;
int? value;
foreach (var element in myDictionary)
  if (String.Equals(element.Key, myKey, comparer))
    value = element.Value;

This saves you the cost of creating a new data structure, but in return the cost of a lookup is O(n) instead of O(1).

Bulk load data conversion error (type mismatch or invalid character for the specified codepage) for row 1, column 4 (Year)

Try using a format file since your data file only has 4 columns. Otherwise, try OPENROWSET or use a staging table.

myTestFormatFiles.Fmt may look like:

1       SQLINT        0       3       ","      1     StudentNo      ""
2       SQLCHAR       0       100     ","      2     FirstName      SQL_Latin1_General_CP1_CI_AS
3       SQLCHAR       0       100     ","      3     LastName       SQL_Latin1_General_CP1_CI_AS
4       SQLINT        0       4       "\r\n"   4     Year           "


This tutorial on skipping a column with BULK INSERT may also help.

Your statement then would look like:

USE xta9354
BULK INSERT xta9354.dbo.Students
    FROM 'd:\userdata\xta9_Students.txt' 
    WITH (FORMATFILE = 'C:\myTestFormatFiles.Fmt')

Postgresql 9.2 pg_dump version mismatch

On Ubuntu you can simply add the most recent Apt repository and then run:

sudo apt-get install postgresql-client-11

try/catch with InputMismatchException creates infinite loop

another option is to define Scanner input = new Scanner(; inside the try block, this will create a new object each time you need to re-enter the values.

VBA Convert String to Date

Looks like it could be throwing the error on the empty data row, have you tried to just make sure itemDate isn't empty before you run the CDate() function? I think this might be your problem.

Google OAuth 2 authorization - Error: redirect_uri_mismatch


  • http or https?
  • & or &amp;?
  • trailing slash(/) or open ?
  • (CMD/CTRL)+F, search for the exact match in the credential page. If not found then search for the missing one.
  • Wait until google refreshes it. May happen in each half an hour if you are changing frequently or it may stay in the pool. For my case it was almost half an hour to take effect.

How to declare and initialize a static const array as a class member?

You are mixing pointers and arrays. If what you want is an array, then use an array:

struct test {
   static int data[10];        // array, not pointer!
int test::data[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

If on the other hand you want a pointer, the simplest solution is to write a helper function in the translation unit that defines the member:

struct test {
   static int *data;
// cpp
static int* generate_data() {            // static here is "internal linkage"
   int * p = new int[10];
   for ( int i = 0; i < 10; ++i ) p[i] = 10*i;
   return p;
int *test::data = generate_data();

Why do I get "MismatchSenderId" from GCM server side?

Please run below script in your terminal

curl -X POST \
-H "Authorization: key=  write here api_key" \
-H "Content-Type: application/json" \
-d '{ 
"registration_ids": [ 
"write here reg_id generated by gcm"
"data": { 
"message": "Manual push notification from Rajkumar"
"priority": "high"
}' \

it will give the message if it is succeeded or failed

Why can't I define my workbook as an object?

You'll need to open the workbook to refer to it.

Sub Setwbk()

    Dim wbk As Workbook

    Set wbk = Workbooks.Open("F:\Quarterly Reports\2012 Reports\New Reports\ _
        Master Benchmark Data Sheet.xlsx")

End Sub

* Follow Doug's answer if the workbook is already open. For the sake of making this answer as complete as possible, I'm including my comment on his answer:

Why do I have to "set" it?

Set is how VBA assigns object variables. Since a Range and a Workbook/Worksheet are objects, you must use Set with these.

Could not load file or assembly 'System.Web.WebPages.Razor, Version=

After my PC got completely reinstalled, I got the error described here. VS 2017 was reinstalled but "ASP.NET Web Pages 2" was not reinstalled. After reinstalling "ASP.NET Web Pages 2", the problem was solved.

See also: Could not load file or assembly System.Web.WebPages.Razor, , Version= or one of its dependencies

BULK INSERT with identity (auto-increment) column

I had a similar issue, but I needed to be sure that the order of the ID is aligning to the order in the source file. My solution is using a VIEW for the BULK INSERT:

Keep your table as it is and create this VIEW (select everything except the ID column)

CREATE VIEW [dbo].[VW_Employee]
SELECT [Name], [Address]
FROM [dbo].[Employee];

Your BULK INSERT should then look like:

BULK INSERT [dbo].[VW_Employee] FROM 'path\tempFile.csv ' 

Headers and client library minor version mismatch

The same works for MySQL:

sudo apt-get install php5-mysqlnd

I've read this thread trying to find the solution for MySQL, and I've also seen ken's answer, but I ignored the solution for MariaDB, wasting a few hours that way. It wasn't clear for me that the same may apply to MySQL. This post is just to spare you the few hours I lost.

Convert List<String> to List<Integer> directly

Use Guava transform method as below,

List intList = Lists.transform(stringList, Integer::parseInt);

PowerMockito mock single static method and return object

What you want to do is a combination of part of 1 and all of 2.

You need to use the PowerMockito.mockStatic to enable static mocking for all static methods of a class. This means make it possible to stub them using the when-thenReturn syntax.

But the 2-argument overload of mockStatic you are using supplies a default strategy for what Mockito/PowerMock should do when you call a method you haven't explicitly stubbed on the mock instance.

From the javadoc:

Creates class mock with a specified strategy for its answers to interactions. It's quite advanced feature and typically you don't need it to write decent tests. However it can be helpful when working with legacy systems. It is the default answer so it will be used only when you don't stub the method call.

The default default stubbing strategy is to just return null, 0 or false for object, number and boolean valued methods. By using the 2-arg overload, you're saying "No, no, no, by default use this Answer subclass' answer method to get a default value. It returns a Long, so if you have static methods which return something incompatible with Long, there is a problem.

Instead, use the 1-arg version of mockStatic to enable stubbing of static methods, then use when-thenReturn to specify what to do for a particular method. For example:

import static org.mockito.Mockito.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

class ClassWithStatics {
  public static String getString() {
    return "String";

  public static int getInt() {
    return 1;

public class StubJustOneStatic {
  public void test() {


    System.out.println("String: " + ClassWithStatics.getString());
    System.out.println("Int: " + ClassWithStatics.getInt());

The String-valued static method is stubbed to return "Hello!", while the int-valued static method uses the default stubbing, returning 0.

How to transform currentTimeMillis to a readable date format?

It will work.

long yourmilliseconds = System.currentTimeMillis();
SimpleDateFormat sdf = new SimpleDateFormat("MMM dd,yyyy HH:mm");    
Date resultdate = new Date(yourmilliseconds);

SVN - Checksum mismatch while updating

I had a similar error and fixed as follows:

(My 'fix' is based on an assumption which may or may not be correct as I don't know that much about how subversion works internally, but it definitely worked for me)

I am assuming that .svn\text-base\import.php.svn-base is expected to match the latest commit.

When I checked the file I was having the error on , the base file did NOT match the latest commit in the repository.

I copied the text from the latest commit and saved that in the .svn folder, replacing the incorrect file (made a backup copy in case my assumptions were wrong). (file was marked read only, I cleared that flag, overwrote and set it back to read only)

I was then able to commit successfully.

Convert Java Array to Iterable

You can use IterableOf from Cactoos:

Iterable<String> names = new IterableOf<>(
  "Scott Fitzgerald", "Fyodor Dostoyevsky"

Then, you can turn it into a list using ListOf:

List<String> names = new ListOf<>(
  new IterableOf<>(
    "Scott Fitzgerald", "Fyodor Dostoyevsky"

Or simply this:

List<String> names = new ListOf<>(
  "Scott Fitzgerald", "Fyodor Dostoyevsky"

How do I fix the Visual Studio compile error, "mismatch between processor architecture"?


  • add a Directory.Build.props file to your solution folder
  • paste this in it:

Deserialize JSON to ArrayList<POJO> using Jackson

I am also having the same problem. I have a json which is to be converted to ArrayList.

Account looks like this.

  Person p ;
  Related r ;


    String Name ;
    Address a ;

All of the above classes have been annotated properly. I have tried TypeReference>() {} but is not working.

It gives me Arraylist but ArrayList has a linkedHashMap which contains some more linked hashmaps containing final values.

My code is as Follows:

public T unmarshal(String responseXML,String c)
    ObjectMapper mapper = new ObjectMapper();

    AnnotationIntrospector introspector = new JacksonAnnotationIntrospector();


      this.targetclass = (T) mapper.readValue(responseXML,  new TypeReference<ArrayList<T>>() {});
    catch (JsonParseException e)
    catch (JsonMappingException e) {
    } catch (IOException e) {

    return this.targetclass;

I finally solved the problem. I am able to convert the List in Json String directly to ArrayList as follows:


     T targetClass ;

     public ArrayList<T> unmarshal(String jsonString)
        ObjectMapper mapper = new ObjectMapper();

        AnnotationIntrospector introspector = new JacksonAnnotationIntrospector();


        JavaType type = mapper.getTypeFactory().
                    constructCollectionType(ArrayList.class, targetclass.getClass()) ;
        Class c1 = this.targetclass.getClass() ;
        Class c2 = this.targetclass1.getClass() ;
            ArrayList<T> temp = (ArrayList<T>) mapper.readValue(jsonString,  type);
        return temp ;
       catch (JsonParseException e)
       catch (JsonMappingException e) {
       } catch (IOException e) {

     return null ;


continuing execution after an exception is thrown in java

If you throw the exception, the method execution will stop and the exception is thrown to the caller method. throw always interrupt the execution flow of the current method. a try/catch block is something you could write when you call a method that may throw an exception, but throwing an exception just means that method execution is terminated due to an abnormal condition, and the exception notifies the caller method of that condition.

Find this tutorial about exception and how they work -

How do I create a Python function with optional arguments?

Try calling it like: obj.some_function( '1', 2, '3', g="foo", h="bar" ). After the required positional arguments, you can specify specific optional arguments by name.

If file exists then delete the file

You're close, you just need to delete the file before trying to over-write it.

dim infolder: set infolder = fso.GetFolder(IN_PATH)
dim file: for each file in infolder.Files

    dim name: name =
    dim parts: parts = split(name, ".")

    if UBound(parts) = 2 then

       ' file name like a.c.pdf    

        dim newname: newname = parts(0) & "." & parts(2)
        dim newpath: newpath = fso.BuildPath(OUT_PATH, newname)

        ' warning:
        ' if we have source files C:\IN_PATH\ABC.01.PDF, C:\IN_PATH\ABC.02.PDF, ...
        ' only one of them will be saved as D:\OUT_PATH\ABC.PDF

        if fso.FileExists(newpath) then
            fso.DeleteFile newpath
        end if

        file.Move newpath

    end if


The specified DSN contains an architecture mismatch between the Driver and Application. JAVA

To solve this problem first make sure that your java software should be 32bit version if it is 64 bit version clearly it will show the mismatch error so try to re-install 32bit of java version And execute the java program in the command of c:\windows\sysWOW64\odbcad32.exe (easiest to copy and paste into run dialog) that's enough your program definitely work

Excel VBA - select multiple columns not in sequential order

Some of the code looks a bit complex to me. This is very simple code to select only the used rows in two discontiguous columns D and H. It presumes the columns are of unequal length and thus more flexible vs if the columns were of equal length.

As you most likely surmised 4=column D and 8=column H

Dim dlastRow As Long
Dim hlastRow As Long

dlastRow = ActiveSheet.Cells(Rows.Count, 4).End(xlUp).Row
hlastRow = ActiveSheet.Cells(Rows.Count, 8).End(xlUp).Row
Range("D2:D" & dlastRow & ",H2:H" & hlastRow).Select


Excel VBA Run-time error '13' Type mismatch

This error occurs when the input variable type is wrong. You probably have written a formula in Cells(4 + i, 57) that instead of =0, the formula = "" have used. So when running this error is displayed. Because empty string is not equal to zero.

enter image description here

Content Type text/xml; charset=utf-8 was not supported by service

Do not forget check the bindings-related code too. So if you wrote:

BasicHttpBinding binding = new BasicHttpBinding();

Be sure that all your app.config files contains

<endpoint address="..."
          binding="basicHttpBinding" ...

not the

<endpoint address="..."
          binding="wsHttpBinding" ...

or so.

Getting "NoSuchMethodError: org.hamcrest.Matcher.describeMismatch" when running test in IntelliJ 10.5

What worked for me was excluding the hamcrest group from the junit test compile.

Here is the code from my build.gradle:

testCompile ('junit:junit:4.11') {
    exclude group: 'org.hamcrest'

If you're running IntelliJ you may need to run gradle cleanIdea idea clean build to detect the dependencies again.

Java compiler level does not match the version of the installed Java project facet

In Eclipse, right click on your project, go to Maven> Update projetc. Wait and the error will disappear. This is already configured correctly the version of Java for this project.

enter image description here

error LNK2038: mismatch detected for '_ITERATOR_DEBUG_LEVEL': value '0' doesn't match value '2' in main.obj

I resolved my trouble in correcting the "Additional Library Directory", this one was wrong in indicating "$(SolutionDir)\Release", I changed it in "$(SolutionDir)\$(IntDir)"

To correct it, open your project properties -> Configuration Properties -> Linker -> General -> Additional Library Directory

I hope this will help some poeples with the same trouble ;)

How do I deal with "signed/unsigned mismatch" warnings (C4018)?

Ideally, I would use a construct like this instead:

for (std::vector<your_type>::const_iterator i = things.begin(); i != things.end(); ++i)
  // if you ever need the distance, you may call std::distance
  // it won't cause any overhead because the compiler will likely optimize the call
  size_t distance = std::distance(things.begin(), i);

This a has the neat advantage that your code suddenly becomes container agnostic.

And regarding your problem, if some library you use requires you to use int where an unsigned int would better fit, their API is messy. Anyway, if you are sure that those int are always positive, you may just do:

int int_distance = static_cast<int>(distance);

Which will specify clearly your intent to the compiler: it won't bug you with warnings anymore.

How do I execute a MS SQL Server stored procedure in java/jsp, returning table data?

FWIW, sp_test will not be returning anything but an integer (all SQL Server stored procs just return an integer) and no result sets on the wire (since no SELECT statements). To get the output of the PRINT statements, you normally use the InfoMessage event on the connection (not the command) in ADO.NET.

how to read a text file using scanner in Java?

Just another thing... Instead of System.out.println("Error Message Here"), use System.err.println("Error Message Here"). This will allow you to distinguish the differences between errors and normal code functioning by displaying the errors(i.e. everything inside System.err.println()) in red.

NOTE: It also works when used with System.err.print("Error Message Here")

ContractFilter mismatch at the EndpointDispatcher exception

I had the same error on a WCF service deployed, the problem was related to another service deployed with another contract with the same port.


I used different ports in the web.config and the issue disappeared.

Service 1


Service 2


Also, I ran into this situation by using diferent port for the same address between the service and the consumer.

Checking for #N/A in Excel cell from VBA code

First check for an error (N/A value) and then try the comparisation against cvErr(). You are comparing two different things, a value and an error. This may work, but not always. Simply casting the expression to an error may result in similar problems because it is not a real error only the value of an error which depends on the expression.

If IsError(ActiveWorkbook.Sheets("Publish").Range("G4").offset(offsetCount, 0).Value) Then
  If (ActiveWorkbook.Sheets("Publish").Range("G4").offset(offsetCount, 0).Value <> CVErr(xlErrNA)) Then
    'do something
  End If
End If

What is float in Java?

Make it

float b= 3.6f;

A floating-point literal is of type float if it is suffixed with an ASCII letter F or f; otherwise its type is double and it can optionally be suffixed with an ASCII letter D or d

How to add items into a numpy array

Appending data to an existing array is a natural thing to want to do for anyone with python experience. However, if you find yourself regularly appending to large arrays, you'll quickly discover that NumPy doesn't easily or efficiently do this the way a python list will. You'll find that every "append" action requires re-allocation of the array memory and short-term doubling of memory requirements. So, the more general solution to the problem is to try to allocate arrays to be as large as the final output of your algorithm. Then perform all your operations on sub-sets (slices) of that array. Array creation and destruction should ideally be minimized.

That said, It's often unavoidable and the functions that do this are:

for 2-D arrays:

for 3-D arrays (the above plus):

for N-D arrays:

Comparing arrays in JUnit assertions, concise built-in way?

Using junit4 and Hamcrest you get a concise method of comparing arrays. It also gives details of where the error is in the failure trace.

import static org.junit.Assert.*
import static org.hamcrest.CoreMatchers.*;


assertThat(result, is(new int[] {56, 100, 2000}));

Failure Trace output:

   Expected: is [<56>, <100>, <2000>]
   but: was [<55>, <100>, <2000>]

How can I use a for each loop on an array?

Element needs to be a variant, so you can't declare it as a string. Your function should accept a variant if it is a string though as long as you pass it ByVal.

Public Sub example()
    Dim sArray(4) As string
    Dim element As variant

    For Each element In sArray
        do_something (element)
    Next element
End Sub

Sub do_something(ByVal e As String)

End Sub

The other option is to convert the variant to a string before passing it.

  do_something CStr(element)

.Net picking wrong referenced assembly version

I had the same message when switching between two versions of an application that referenced different versions of the same DLL. Although I was testing in different folders I accidentally copied the newer version over the older version.

So the first thing to check is the version of the referenced DLL in the application's folder. Just in case.

How to capitalize the first letter of a String in Java?

You can use Class WordUtils.

Suppose your String is "current address" then use

****strong textWordutils.capitaliz(String); output : Current Address


Compiling C++ on remote Linux machine - "clock skew detected" warning

According to user m9dhatter on

"make" uses the time stamp of the file to determine if the file it is trying to compile is old or new. if your clock is bonked, it may have problems compiling.

if you try to modify files at another machine with a clock time ahead by a few minutes and transfer them to your machine and then try to compile it may cough up a warning that says the file was modified from the future. clock may be skewed or something to that effect ( cant really remember ). you could just ls to the offending file and do this:

#touch <filename of offending file>

Java: Integer equals vs. ==

Besides these given great answers, What I have learned is that:

NEVER compare objects with == unless you intend to be comparing them by their references.

Why maven? What are the benefits?

I've never come across point 2? Can you explain why you think this affects deployment in any way. If anything maven allows you to structure your projects in a modularised way that actually allows hot fixes for bugs in a particular tier, and allows independent development of an API from the remainder of the project for example.

It is possible that you are trying to cram everything into a single module, in which case the problem isn't really maven at all, but the way you are using it.

Using custom std::set comparator

std::less<> when using custom classes with operator<

If you are dealing with a set of your custom class that has operator< defined, then you can just use std::less<>.

As mentioned at C++14 has added two new find APIs:

template< class K > iterator find( const K& x );
template< class K > const_iterator find( const K& x ) const;

which allow you to do:


#include <cassert>
#include <set>

class Point {
        // Note that there is _no_ conversion constructor,
        // everything is done at the template level without
        // intermediate object creation.
        //Point(int x) : x(x) {}
        Point(int x, int y) : x(x), y(y) {}
        int x;
        int y;
bool operator<(const Point& c, int x) { return c.x < x; }
bool operator<(int x, const Point& c) { return x < c.x; }
bool operator<(const Point& c, const Point& d) {
    return c.x < d;

int main() {
    std::set<Point, std::less<>> s;
    s.insert(Point(1, -1));
    s.insert(Point(2, -2));
    s.insert(Point(0,  0));
    s.insert(Point(3, -3));
    assert(s.find(0)->y ==  0);
    assert(s.find(1)->y == -1);
    assert(s.find(2)->y == -2);
    assert(s.find(3)->y == -3);
    // Ignore 1234, find 1.
    assert(s.find(Point(1, 1234))->y == -1);

Compile and run:

g++ -std=c++14 -Wall -Wextra -pedantic -o main.out main.cpp

More info about std::less<> can be found at: What are transparent comparators?

Tested on Ubuntu 16.10, g++ 6.2.0.

QR Code encoding and decoding using zxing

For what it's worth, my groovy spike seems to work with both UTF-8 and ISO-8859-1 character encodings. Not sure what will happen when a non zxing decoder tries to decode the UTF-8 encoded image though... probably varies depending on the device.

// ------------------------------------------------------------------------------------
// Requires: groovy-1.7.6, jdk1.6.0_03, ./lib with zxing core-1.7.jar, javase-1.7.jar 
// Javadocs:
// Run with: groovy -cp "./lib/*" zxing.groovy
// ------------------------------------------------------------------------------------


import java.awt.image.BufferedImage
import javax.imageio.ImageIO

def class zxing {
    def static main(def args) {
        def filename = "./qrcode.png"
        def data = "This is a test to see if I can encode and decode this data..."
        def charset = "UTF-8" //"ISO-8859-1" 
        def hints = new Hashtable<EncodeHintType, String>([(EncodeHintType.CHARACTER_SET): charset])

        writeQrCode(filename, data, charset, hints, 100, 100)

        assert data == readQrCode(filename, charset, hints)

    def static writeQrCode(def filename, def data, def charset, def hints, def width, def height) {
        BitMatrix matrix = new MultiFormatWriter().encode(new String(data.getBytes(charset), charset), BarcodeFormat.QR_CODE, width, height, hints)
        MatrixToImageWriter.writeToFile(matrix, filename.substring(filename.lastIndexOf('.')+1), new File(filename))

    def static readQrCode(def filename, def charset, def hints) {
        BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource( FileInputStream(filename)))))
        Result result = new MultiFormatReader().decode(binaryBitmap, hints)



Java: how do I get a class literal from a generic type?

You can manage it with a double cast :

@SuppressWarnings("unchecked") Class<List<Foo>> cls = (Class<List<Foo>>)(Object)List.class

How to re-sync the Mysql DB if Master and slave have different database incase of Mysql replication?

I am very late to this question, however I did encounter this problem and, after much searching, I found this information from Bryan Kennedy:

On Master take a backup like this:
mysqldump --skip-lock-tables --single-transaction --flush-logs --hex-blob --master-data=2 -A > ~/dump.sql

Now, examine the head of the file and jot down the values for MASTER_LOG_FILE and MASTER_LOG_POS. You will need them later: head dump.sql -n80 | grep "MASTER_LOG"

Copy the "dump.sql" file over to Slave and restore it: mysql -u mysql-user -p < ~/dump.sql

Connect to Slave mysql and run a command like this: CHANGE MASTER TO MASTER_HOST='master-server-ip', MASTER_USER='replication-user', MASTER_PASSWORD='slave-server-password', MASTER_LOG_FILE='value from above', MASTER_LOG_POS=value from above; START SLAVE;

To check the progress of Slave: SHOW SLAVE STATUS;

If all is well, Last_Error will be blank, and Slave_IO_State will report “Waiting for master to send event”. Look for Seconds_Behind_Master which indicates how far behind it is. YMMV. :)

"Faceted Project Problem (Java Version Mismatch)" error message

The project facets should be derived automagically by the M2Eclipse plugin from the POM configuration. If you make some changes to the POM and need Eclipse to take them into account, right-click on your project, then go to Maven > Update Project Configuration. You should not set project facets manually.

WCF Error "This could be due to the fact that the server certificate is not configured properly with HTTP.SYS in the HTTPS case"

In my case I had to enable SchUseStrongCrypto for .Net This forces the server to make connection by using TLS 1.0, 1.1 or 1.2. Without SchUseStrongCrypto enabled the connection was trying to use SSL 3.0, which was disabled at my remote endpoint.

Registry keys to enable use of strong crypto:



Ruby/Rails: converting a Date to a UNIX timestamp

Solution for Ruby 1.8 when you have an arbitrary DateTime object:

1.8.7-p374 :001 > require 'date'
 => true 
1.8.7-p374 :002 >, 1, 15).strftime('%s')
 => "1326585600"

How to recover Git objects damaged by hard disk failure?

Banengusk was putting me on the right track. For further reference, I want to post the steps I took to fix my repository corruption. I was lucky enough to find all needed objects either in older packs or in repository backups.

# Unpack last non-corrupted pack
$ mv .git/objects/pack .git/objects/pack.old
$ git unpack-objects -r < .git/objects/pack.old/pack-012066c998b2d171913aeb5bf0719fd4655fa7d0.pack
$ git log
fatal: bad object HEAD

$ cat .git/HEAD 
ref: refs/heads/master

$ ls .git/refs/heads/

$ cat .git/packed-refs 
# pack-refs with: peeled 
aa268a069add6d71e162c4e2455c1b690079c8c1 refs/heads/master

$ git fsck --full 
error: HEAD: invalid sha1 pointer aa268a069add6d71e162c4e2455c1b690079c8c1
error: refs/heads/master does not point to a valid object!
missing blob 75405ef0e6f66e48c1ff836786ff110efa33a919
missing blob 27c4611ffbc3c32712a395910a96052a3de67c9b
dangling tree 30473f109d87f4bcde612a2b9a204c3e322cb0dc

# Copy HEAD object from backup of repository
$ cp repobackup/.git/objects/aa/268a069add6d71e162c4e2455c1b690079c8c1 .git/objects/aa
# Now copy all missing objects from backup of repository and run "git fsck --full" afterwards
# Repeat until git fsck --full only reports dangling objects

# Now garbage collect repo
$ git gc
warning: reflog of 'HEAD' references pruned commits
warning: reflog of 'refs/heads/master' references pruned commits
Counting objects: 3992, done.
Delta compression using 2 threads.
fatal: object bf1c4953c0ea4a045bf0975a916b53d247e7ca94 inconsistent object length (6093 vs 415232)
error: failed to run repack

# Check reflogs...
$ git reflog

# ...then clean
$ git reflog expire --expire=0 --all

# Now garbage collect again
$ git gc       
Counting objects: 3992, done.
Delta compression using 2 threads.
Compressing objects: 100% (3970/3970), done.
Writing objects: 100% (3992/3992), done.
Total 3992 (delta 2060), reused 0 (delta 0)
Removing duplicate objects: 100% (256/256), done.
# Done!

Ship an application with a database

In November 2017 Google released the Room Persistence Library.

From the documentation:

The Room persistence library provides an abstraction layer over SQLite to allow fluent database access while harnessing the full power of SQLite.

The library helps you create a cache of your app's data on a device that's running your app. This cache, which serves as your app's single source of truth, allows users to view a consistent copy of the key information within your app, regardless of whether users have an internet connection.

The Room database has a callback when the database is first created or opened. You can use the create callback to populate your database.

Room.databaseBuilder(context.applicationContext,, "Sample.db")
        // prepopulate the database after onCreate was called
        .addCallback(object : Callback() {
            override fun onCreate(db: SupportSQLiteDatabase) {
                // moving to a new thread
                ioThread {

Code from this blog post.

UTF-8 all the way through

Unicode support in PHP is still a huge mess. While it's capable of converting an ISO8859 string (which it uses internally) to utf8, it lacks the capability to work with unicode strings natively, which means all the string processing functions will mangle and corrupt your strings. So you have to either use a separate library for proper utf8 support, or rewrite all the string handling functions yourself.

The easy part is just specifying the charset in HTTP headers and in the database and such, but none of that matters if your PHP code doesn't output valid UTF8. That's the hard part, and PHP gives you virtually no help there. (I think PHP6 is supposed to fix the worst of this, but that's still a while away)

Find where java class is loaded from

Take a look at this similar question. Tool to discover same class..

I think the most relevant obstacle is if you have a custom classloader ( loading from a db or ldap )

Most efficient way to check for DBNull and then assign to a variable?

There is the troublesome case where the object could be a string. The below extension method code handles all cases. Here's how you would use it:

    static void Main(string[] args)
        object number = DBNull.Value;

        int newNumber = number.SafeDBNull<int>();


    public static T SafeDBNull<T>(this object value, T defaultValue) 
        if (value == null)
            return default(T);

        if (value is string)
            return (T) Convert.ChangeType(value, typeof(T));

        return (value == DBNull.Value) ? defaultValue : (T)value;

    public static T SafeDBNull<T>(this object value) 
        return value.SafeDBNull(default(T)); 

How do I format a Microsoft JSON date?

For those using Newtonsoft Json.NET, read up on how to do it via Native JSON in IE8, Firefox 3.5 plus Json.NET.

Also the documentation on changing the format of dates written by Json.NET is useful: Serializing Dates with Json.NET

For those that are too lazy, here are the quick steps. As JSON has a loose DateTime implementation, you need to use the IsoDateTimeConverter(). Note that since Json.NET 4.5 the default date format is ISO so the code below isn't needed.

string jsonText = JsonConvert.SerializeObject(p, new IsoDateTimeConverter());

The JSON will come through as

"fieldName": "2009-04-12T20:44:55"

Finally, some JavaScript to convert the ISO date to a JavaScript date:

function isoDateReviver(value) {
  if (typeof value === 'string') {
    var a = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)(?:([\+-])(\d{2})\:(\d{2}))?Z?$/.exec(value);
      if (a) {
        var utcMilliseconds = Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], +a[5], +a[6]);
        return new Date(utcMilliseconds);
  return value;

I used it like this

$("<span />").text(isoDateReviver(item.fieldName).toLocaleString()).appendTo("#" + divName);

Passing an array by reference in C?

In plain C you can use a pointer/size combination in your API.

void doSomething(MyStruct* mystruct, size_t numElements)
    for (size_t i = 0; i < numElements; ++i)
        MyStruct current = mystruct[i];

Using pointers is the closest to call-by-reference available in C.

What port number does SOAP use?

SOAP (communication protocol) for communication between applications. Uses HTTP (port 80) or SMTP ( port 25 or 2525 ), for message negotiation and transmission.

Generate random numbers uniformly over an entire range

This is the solution I came up with:

#include "<stdlib.h>"

int32_t RandomRange(int32_t min, int32_t max) {
    return (rand() * (max - min + 1) / (RAND_MAX + 1)) + min;

This is a bucket solution, conceptually similar to the solutions that use rand() / RAND_MAX to get a floating point range between 0-1 and then round that into a bucket. However, it uses purely integer math, and takes advantage of integer division flooring to round down the value to the nearest bucket.

It makes a few assumptions. First, it assumes that RAND_MAX * (max - min + 1) will always fit within an int32_t. If RAND_MAX is 32767 and 32 bit int calculations are used, the the maximum range you can have is 32767. If your implementation has a much larger RAND_MAX, you can overcome this by using a larger integer (like int64_t) for the calculation. Secondly, if int64_t is used but RAND_MAX is still 32767, at ranges greater than RAND_MAX you will start to get "holes" in the possible output numbers. This is probably the biggest issue with any solution derived from scaling rand().

Testing over a huge number of iterations nevertheless shows this method to be very uniform for small ranges. However, it is possible (and likely) that mathematically this has some small bias and possibly develops issues when the range approaches RAND_MAX. Test it for yourself and decide if it meets your needs.

jQuery: how do I animate a div rotation?

As of now you still can't animate rotations with jQuery, but you can with CSS3 animations, then simply add and remove the class with jQuery to make the animation occur.

JSFiddle demo


<img src="" width="30" height="30"/>


img {
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
transform: rotate(-90deg);

.rotate {
-webkit-transform: rotate(0deg);
-moz-transform: rotate(0deg);
-o-transform: rotate(0deg);
-ms-transform: rotate(0deg);
transform: rotate(0deg);


$(document).ready(function() {
    $("img").mouseenter(function() {
    $("img").mouseleave(function() {

How to convert .pfx file to keystore with private key?

Justin(above) is accurate. However, keep in mind that depending on who you get the certificate from (intermediate CA, root CA involved or not) or how the pfx is created/exported, sometimes they could be missing the certificate chain. After Import, You would have a certificate of PrivateKeyEntry type, but with a chain of length of 1.

To fix this, there are several options. The easier option in my mind is to import and export the pfx file in IE(choosing the option of Including all the certificates in the chain). The import and export process of certificates in IE should be very easy and well documented elsewhere.

Once exported, import the keystore as Justin pointed above. Now, you would have a keystore with certificate of type PrivateKeyEntry and with a certificate chain length of more than 1.

Certain .Net based Web service clients error out(unable to establish trust relationship), if you don't do the above.

How to edit my Excel dropdown list?

Attribute_Brands is a named range that should contain your list items. Use the drop down to the left of the formula bar to jump to the named range, then edit it. If you add or remove items you will need to adjust the range the named range covers.

De-obfuscate Javascript code to make it readable again

From the first link on google;

function call_func(_0x41dcx2) {
 var _0x41dcx3 = eval('(' + _0x41dcx2 + ')');
 var _0x41dcx4 = document['createElement']('div');
 var _0x41dcx5 = _0x41dcx3['id'];
 var _0x41dcx6 = _0x41dcx3['Student_name'];
 var _0x41dcx7 = _0x41dcx3['student_dob'];
 var _0x41dcx8 = '<b>ID:</b>';
 _0x41dcx8 += '<a href="/learningyii/index.php?r=student/view&amp; id=' + _0x41dcx5 + '">' + _0x41dcx5 + '</a>';
 _0x41dcx8 += '<br/>';
 _0x41dcx8 += '<b>Student Name:</b>';
 _0x41dcx8 += _0x41dcx6;
 _0x41dcx8 += '<br/>';
 _0x41dcx8 += '<b>Student DOB:</b>';
 _0x41dcx8 += _0x41dcx7;
 _0x41dcx8 += '<br/>';
 _0x41dcx4['innerHTML'] = _0x41dcx8;
 _0x41dcx4['setAttribute']('class', 'view');

It won't get you all the way back to source, and that's not really possible, but it'll get you out of a hole.

How to create a connection string in c#

It occurs when IIS is not being connected to SQL SERVER. For a solution, see this screenshot: Solution

HTML button to NOT submit form

For accessibility reason, I could not pull it off with multiple type=submit buttons. The only way to work natively with a form with multiple buttons but ONLY one can submit the form when hitting the Enter key is to ensure that only one of them is of type=submit while others are in other type such as type=button. By this way, you can benefit from the better user experience in dealing with a form on a browser in terms of keyboard support.

How to use Session attributes in Spring-mvc

The below annotated code would set "value" to "name"

public class TestController {
@RequestMapping(method = RequestMethod.GET)
public String testMestod(HttpServletRequest request){
    request.getSession().setAttribute("name", "value");
    return "testJsp";

To access the same in JSP use ${}.

For the @ModelAttribute see this link

Logical XOR operator in C++?

The XOR operator cannot be short circuited; i.e. you cannot predict the result of an XOR expression just by evaluating its left hand operand. Thus, there's no reason to provide a ^^ version.

Alter column, add default constraint

You're specifying the table name twice. The ALTER TABLE part names the table. Try: Alter table TableName alter column [Date] default getutcdate()

highlight the navigation menu for the current page

I usually use a class to achieve this. It's very simple to implement to anything, navigation links, hyperlinks and etc.

In your CSS document insert:

nav li a:hover {
   /* styles go here */
   color: #e00122;
   background-color: #fffff;

This will make the hover state of the list items have red text and a white background. Attach that class of current to any link on the "current" page and it will display the same styles.

Im your HTML insert:

      <li class="current"><a href="#">Nav Item 1</a></li>
      <li><a href="#">Nav Item 2</a></li>
      <li><a href="#">Nav Item 3</a></li>

Exception from HRESULT: 0x800A03EC Error

Got this error also....

it occurs when save to filepath contains invalid characters, in my case:

path = "C:/somefolder/anotherfolder\file.xls";

Note the existence of both \ and /

*Also may occur if trying to save to directory which doesn't already exist.

How to fix org.hibernate.LazyInitializationException - could not initialize proxy - no Session

If you using Spring mark the class as @Transactional, then Spring will handle session management.

public class MyClass {

By using @Transactional, many important aspects such as transaction propagation are handled automatically. In this case if another transactional method is called the method will have the option of joining the ongoing transaction avoiding the "no session" exception.

WARNING If you do use @Transactional, please be aware of the resulting behavior. See this article for common pitfalls. For example, updates to entities are persisted even if you don't explicitly call save

jQuery multiple conditions within if statement

A more general approach:

if ( ($("body").hasClass("homepage") || $("body").hasClass("contact")) && (theLanguage == 'en-gb') )   {

       // Do something


Xcode variables

The best source is probably Apple's official documentation. The specific variable you are looking for is CONFIGURATION.

Tried to Load Angular More Than Once

Another case is with Webpack which concating angular into the bundle.js, beside the angular that is loaded from index.html <script> tag.

this was because we used explicit importing of angular in many files:

define(['angular', ...], function(angular, ...){

so, webpack decided to bundle it too. cleaning all of those into:

define([...], function(...){

was fixing Tried to Load Angular More Than Once for once and all.

Twitter Bootstrap scrollable table rows and fixed header

Just stack two bootstrap tables; one for columns, the other for content. No plugins, just pure bootstrap (and that ain't no bs, haha!)

  <table id="tableHeader" class="table" style="table-layout:fixed">
  <div style="overflow-y:auto;">
    <table id="tableData" class="table table-condensed" style="table-layout:fixed">

Demo JSFiddle

The content table div needs overflow-y:auto, for vertical scroll bars. Had to use table-layout:fixed, otherwise, columns did not line up. Also, had to put the whole thing inside a bootstrap panel to eliminate space between the tables.

Have not tested with custom column widths, but provided you keep the widths consistent between the tables, it should work.

    $(function () {

        //copy width of header cells to match width of cells with data
        //so they line up properly
        var tdHeader = document.getElementById("tableHeader").rows[0].cells;
        var tdData = document.getElementById("tableData").rows[0].cells;

        for (var i = 0; i < tdData.length; i++)
            tdHeader[i].style.width = tdData[i].offsetWidth + 'px';


Cluster analysis in R: determine the optimal number of clusters

It's hard to add something too such an elaborate answer. Though I feel we should mention identify here, particularly because @Ben shows a lot of dendrogram examples.

d_dist <- dist(as.matrix(d))   # find distance matrix 
clusters <- identify(hclust(d_dist))

identify lets you interactively choose clusters from an dendrogram and stores your choices to a list. Hit Esc to leave interactive mode and return to R console. Note, that the list contains the indices, not the rownames (as opposed to cutree).

php get values from json encode

json_decode will return the same array that was originally encoded. For instanse, if you

$array = json_decode($json, true);
echo $array['countryId'];


$obj= json_decode($json);

echo $obj->countryId;

These both will echo 84. I think json_encode and json_decode function names are self-explanatory...

How to set MouseOver event/trigger for border in XAML?

Yes, this is confusing...

According to this blog post, it looks like this is an omission from WPF.

To make it work you need to use a style:

    <Border Name="ClearButtonBorder" Grid.Column="1" CornerRadius="0,3,3,0">
                <Setter Property="Border.Background" Value="Blue"/>
                    <Trigger Property="Border.IsMouseOver" Value="True">
                        <Setter Property="Border.Background" Value="Green" />
        <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="X" />

I guess this problem isn't that common as most people tend to factor out this sort of thing into a style, so it can be used on multiple controls.

Uncaught TypeError: Cannot read property 'msie' of undefined - jQuery tools

Use like blow

$(function (a) {

. . . . .then in your function you can using msie property like

if (a.browser.msie) 


Understanding ASP.NET Eval() and Bind()

The question was answered perfectly by Darin Dimitrov, but since ASP.NET 4.5, there is now a better way to set up these bindings to replace* Eval() and Bind(), taking advantage of the strongly-typed bindings.

*Note: this will only work if you're not using a SqlDataSource or an anonymous object. It requires a Strongly-typed object (from an EF model or any other class).

This code snippet shows how Eval and Bind would be used for a ListView control (InsertItem needs Bind, as explained by Darin Dimitrov above, and ItemTemplate is read-only (hence they're labels), so just needs an Eval):

<asp:ListView ID="ListView1" runat="server" DataKeyNames="Id" InsertItemPosition="LastItem" SelectMethod="ListView1_GetData" InsertMethod="ListView1_InsertItem" DeleteMethod="ListView1_DeleteItem">
            Title: <asp:TextBox ID="Title" runat="server" Text='<%# Bind("Title") %>'/><br />         
            Description: <asp:TextBox ID="Description" runat="server" TextMode="MultiLine" Text='<%# Bind("Description") %>' /><br />        
            <asp:Button ID="InsertButton" runat="server" Text="Insert" CommandName="Insert" />        
            Title: <asp:Label ID="Title" runat="server" Text='<%#  Eval("Title") %>' /><br />
            Description: <asp:Label ID="Description" runat="server" Text='<%# Eval("Description") %>' /><br />        
            <asp:Button ID="DeleteButton" runat="server" Text="Delete" CommandName="Delete" CausesValidation="false"/>

From ASP.NET 4.5+, data-bound controls have been extended with a new property ItemType, which points to the type of object you're assigning to its data source.

<asp:ListView ItemType="Picture" ID="ListView1" runat="server" ...>

Picture is the strongly type object (from EF model). We then replace:

Bind(property) ->
Eval(property) ->

So this:

<%# Bind("Title") %>      
<%# Bind("Description") %>         
<%#  Eval("Title") %> 
<%# Eval("Description") %>

Would become this:

<%# BindItem.Title %>         
<%# BindItem.Description %>
<%# Item.Title %>
<%# Item.Description %>

Advantages over Eval & Bind:

  • IntelliSense can find the correct property of the object your're working withenter image description here
  • If property is renamed/deleted, you will get an error before page is viewed in browser
  • External tools (requires full versions of VS) will correctly rename item in markup when you rename a property on your object

Source: from this excellent book

Faster alternative in Oracle to SELECT COUNT(*) FROM sometable

If the table has an index on a NOT NULL column the COUNT(*) will use that. Otherwise it is executes a full table scan. Note that the index doesn't have to be UNIQUE it just has to be NOT NULL.

Here is a table...

SQL> desc big23
 Name                                      Null?    Type
 ----------------------------------------- -------- ---------------------------
 PK_COL                                    NOT NULL NUMBER
 COL_1                                              VARCHAR2(30)
 COL_2                                              VARCHAR2(30)
 COL_3                                              NUMBER
 COL_4                                              DATE
 COL_5                                              NUMBER
 NAME                                               VARCHAR2(10)


First we'll do a count with no indexes ....

SQL> explain plan for
  2      select count(*) from big23
  3  /


SQL> select * from table(dbms_xplan.display)
  2  /
select * from table)dbms_xplan.display)

Plan hash value: 983596667

| Id  | Operation          | Name  | Rows  | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT   |       |     1 |  1618   (1)| 00:00:20 |
|   1 |  SORT AGGREGATE    |       |     1 |            |          |
|   2 |   TABLE ACCESS FULL| BIG23 |   472K|  1618   (1)| 00:00:20 |


   - dynamic sampling used for this statement

13 rows selected.


No we create an index on a column which can contain NULL entries ...

SQL> create index i23 on big23(col_5)
  2  /

Index created.

SQL> delete from plan_table
  2  /

3 rows deleted.

SQL> explain plan for
  2      select count(*) from big23
  3  /


SQL> select * from table(dbms_xplan.display)
  2  /

Plan hash value: 983596667

| Id  | Operation          | Name  | Rows  | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT   |       |     1 |  1618   (1)| 00:00:20 |
|   1 |  SORT AGGREGATE    |       |     1 |            |          |
|   2 |   TABLE ACCESS FULL| BIG23 |   472K|  1618   (1)| 00:00:20 |


   - dynamic sampling used for this statement

13 rows selected.


Finally let's build the index on the NOT NULL column ....

SQL> drop index i23
  2  /

Index dropped.

SQL> create index i23 on big23(pk_col)
  2  /

Index created.

SQL> delete from plan_table
  2  /

3 rows deleted.

SQL> explain plan for
  2      select count(*) from big23
  3  /


SQL> select * from table(dbms_xplan.display)
  2  /

Plan hash value: 1352920814

| Id  | Operation             | Name | Rows  | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT      |      |     1 |   326   (1)| 00:00:04 |
|   1 |  SORT AGGREGATE       |      |     1 |            |          |
|   2 |   INDEX FAST FULL SCAN| I23  |   472K|   326   (1)| 00:00:04 |


   - dynamic sampling used for this statement

13 rows selected.


Angular and Typescript: Can't find names - Error: cannot find name

There is a work-around mentioned in the changelog for 2.0.0-beta.6 (2016-02-11) (listed under breaking changes):

If you use --target=es5, you will need to add a line somewhere in your application (for example, at the top of the .ts file where you call bootstrap):

///<reference path="node_modules/angular2/typings/browser.d.ts"/>

(Note that if your file is not in the same directory as node_modules, you'll need to add one or more ../ to the start of that path.)

make sure you have the correct reference path, i needed to add ../ to the start to get this working.

const char* concatenation

It seems like you're using C++ with a C library and therefore you need to work with const char *.

I suggest wrapping those const char * into std::string:

const char *a = "hello "; 
const char *b = "world"; 
std::string c = a; 
std::string d = b; 
cout << c + d;

Apache HttpClient Interim Error: NoHttpResponseException

Nowadays, most HTTP connections are considered persistent unless declared otherwise. However, to save server ressources the connection is rarely kept open forever, the default connection timeout for many servers is rather short, for example 5 seconds for the Apache httpd 2.2 and above.

The org.apache.http.NoHttpResponseException error comes most likely from one persistent connection that was closed by the server.

It's possible to set the maximum time to keep unused connections open in the Apache Http client pool, in milliseconds.

With Spring Boot, one way to achieve this:

public class RestTemplateCustomizers {
    static public class MaxConnectionTimeCustomizer implements RestTemplateCustomizer {

        public void customize(RestTemplate restTemplate) {
            HttpClient httpClient = HttpClientBuilder
                .setConnectionTimeToLive(1000, TimeUnit.MILLISECONDS)

                new HttpComponentsClientHttpRequestFactory(httpClient));

// In your service that uses a RestTemplate
public MyRestService(RestTemplateBuilder builder ) {
    restTemplate = builder
         .customizers(new RestTemplateCustomizers.MaxConnectionTimeCustomizer())

How do I get a value of in Python that is "timezone aware"?

Here's a stdlib solution that works on both Python 2 and 3:

from datetime import datetime

now = # Timezone-aware datetime.utcnow()
today = datetime(now.year, now.month,, tzinfo=utc) # Midnight

where today is an aware datetime instance representing the beginning of the day (midnight) in UTC and utc is a tzinfo object (example from the documentation):

from datetime import tzinfo, timedelta

ZERO = timedelta(0)

class UTC(tzinfo):
    def utcoffset(self, dt):
        return ZERO

    def tzname(self, dt):
        return "UTC"

    def dst(self, dt):
        return ZERO

utc = UTC()

Related: performance comparison of several ways to get midnight (start of a day) for a given UTC time. Note: it is more complex, to get midnight for a time zone with a non-fixed UTC offset.

How can you zip or unzip from the script using ONLY Windows' built-in capabilities?

It isn't exactly a ZIP, but the only way to compress a file using Windows tools is:

makecab <source> <dest>.cab

To decompress:

expand <source>.cab <dest>

Advanced example (from

Create a self extracting archive containing
C:\> makecab ""
C:\> copy /b "%windir%\system32\extrac32.exe"+"" "movie.exe"
C:\> del /q /f ""

More information: makecab, expand, makecab advanced uses

How do I clear all options in a dropdown box?

Note that a select can have both
- optgroup &
- options collection
as its children.


Method #1

var selectElement = document.getElementById('myselectid');
selectElement.innerHTML = '';

Method #2

var selectElement = document.getElementById('myselectid');
selectElement.textContent = '';

I tested, both work on Chrome.
I like the simpler, the old fashioned, method #1.

How to post query parameters with Axios?

As of 2021 insted of null i had to add {} in order to make it work!
          params: {
      .then(response => {
        return success(response);
      .catch(error => {
        return fail(error);

Store JSON object in data attribute in HTML jQuery

!DOCTYPE html>

<script src=""></script>
person = new Object(); = "vishal";
person.age =20;


<button id="btn1">Attach data to div element</button><br>
<button id="btn2">Get data attached to div element</button>


Anser:-Attach data to selected elements using an object with name/value pairs.
GET value using object propetis like name,age etc...

LINQ equivalent of foreach for IEnumerable<T>

Fredrik has provided the fix, but it may be worth considering why this isn't in the framework to start with. I believe the idea is that the LINQ query operators should be side-effect-free, fitting in with a reasonably functional way of looking at the world. Clearly ForEach is exactly the opposite - a purely side-effect-based construct.

That's not to say this is a bad thing to do - just thinking about the philosophical reasons behind the decision.

Error in <my code> : object of type 'closure' is not subsettable

I had this issue was trying to remove a ui element inside an event reactive:

myReactives <- eventReactive(input$execute, {
    ... # Some other long running function here
    removeUI(selector = "#placeholder2")

I was getting this error, but not on the removeUI element line, it was in the next observer after for some reason. Taking the removeUI method out of the eventReactive and placing it somewhere else removed this error for me.

How do I remove a submodule?

For the benefit of the reader, this here tries to sum it up and give a step-by-step guide on how to do it if things do not work as expected. Following is the tested and safe way for git version 2.17 and above to get rid of a submodule:

submodule="path/to/sub"              # no trailing slash!
git submodule deinit -- "$submodule"
git rm -- "$submodule"
  • If this does not work for you, see below.
  • No options. Nothing dangerous. And do not even consider doing more!
  • Tested with Debian Buster 2.20.1 and Ubuntu 18.04 2.17.1.
  • "$submodule" is just to emphasize where to put the name, and that you have to be careful with spaces and the like
  • If on Windows ignore the first line and replace "$submodule" with the Windows way of a properly specified path to the submodule. (I am not Windows)


Never touch the insides of the .git directory yourself! Editing inside .git enters the dark side. Stay away at all cost!

And yes, you can blame git for this, as many handy things were missing in git in the past. Like a proper way to remove submodules again.

I think there is a very dangerous part in the documentation of git submodule. It recommends to remove $GIT_DIR/modules/<name>/ yourself. In my understanding this is not only plain wrong, it is extremely dangerous and provokes major headaches in future! See below.

Note that

git module deinit

is the direct inverse to

git module init


git submodule deinit -- module
git rm -- module

also is quite the inverse to

git submodule add -- URL module
git submodule update --init --recursive -- module

because some commands basically need to do more than just a single thing:

  • git submodule deinit -- module
    • (1) updates .git/config
  • git rm
    • (2) removes the files of the module
    • (3) thereby recursively removes the submodules of the submodule
    • (4) updates .gitmodules
  • git submodule add
    • pulls in the data to .git/modules/NAME/
    • (1) does git submodule init, so updates .git/config
    • (2) does git submodule update, so, nonrecursively checks out the module
    • (4) updates .gitmodules
  • git submodule update --init --recursive -- module
    • pulls in further data if needed
    • (3) checks out the submodules of the submodule recursively

This cannot be fully symmetric, as keeping it strictly symmetric does not make much sense. There simply is no need for more than two commands. Also "pulling in the data" is implicit, because you need it, but removing the cached information is not done, because this is not needed at all and might wipe precious data.

This truly is puzzling to newcomers, but basically is a good thing: git just does the obviously thing and does that right, and does not even try to do more. git is a tool, which must do a reliable job, instead of being just another "Eierlegende Wollmilchsau" ("Eierlegende Wollmilchsau" translates for me to "some evil version of a Swiss army knife").

So I understand complaints of people, saying "Why doesn't do git the obvious thing for me". This is because "obvious" here depends from the point of view. Reliability in each and every situation is far more important. Hence what's obvious for you often is not the right thing in all possible technical situations. Please remember that: AFAICS git follows the technical path, not the social one. (Hence the clever name: git)

If this fails

The commands above may fail due to following:

  • Your git is too old. Then use a newer git. (See below how to.)
  • You have uncommitted data and might lose data. Then better commit them first.
  • Your submodule is not clean in a git clean sense. Then first clean your submodule using that command. (See below.)
  • You have done something in the past which is unsupported by git. Then you are on the dark side and things get ugly and complicated. (Perhaps using another machine fixes it.)
  • Perhaps there are more ways to fail I am not aware of (I am just some git power-user.)

Possible fixes follow.

Use a newer git

If your machine is too old there is no submodule deinit in your git. If you do not want (or can) update your git, then just use another machine with a newer git! git is meant to be fully distributed, so you can use another git to get the job done:

  • workhorse:~/path/to/worktree$ git status --porcelain must not output anything! If it does, cleanup things first!
  • workhorse:~/path/to/worktree$ ssh account@othermachine
  • othermachine:~$ git clone --recursive me@workhorse path/to/worktree/.git TMPWORK && cd TMPWORK
  • Now do the submodule stuff
  • othermachine:~/TMPWORK$ git commit . -m . && exit
  • workhorse:~/path/to/worktree$ git fetch account@othermachine:TMPWORK/.git
  • workhorse:~/path/to/worktree$ git merge --ff-only FETCH_HEAD. If this does not work, use git reset --soft FETCH_HEAD
  • Now cleanup things, until git status is clean again. You are able to do so, because you have had it clean before, thanks to the first step.

This othermachine can be some VM, or some Ubuntu WSL under Windows, whatever. Even a chroot (but I assume that you are non-root, because if you are root it should be more easy to update to the newer git).

Note that if you cannot ssh in, there are trainloads of ways to transport git repositories. You can copy your worktree on some USB stick (including the .git directory), and clone from the stick. Clone the copy, just to get things in a clean fashion again. This might be a PITA, in case your submodules are not accessible from othermachine directly. But there is a solution for this, too:

git config --add url.NEWURLPREFIX.insteadOf ORIGINALURLPREFIX

You can use this multiply, and this is saved into $HOME/.gitconfig. Something like

git config --add 'url./mnt/usb/repo/.insteadof'

rewrites URLs like



It's easy if you start to become accustomed to powerful git features like this.

Cleanup things first

Cleaning manually up is good, because this way you perhaps detect some things you forgot about.

  • If git complains about unsaved stuff, commit and push it somewhere safe.
  • If git complains about some leftovers, git status and git clean -ixfd is your friend
  • Try to abstain from options to rm and deinit as long as you can. Options (like -f) for git are good if you are a Pro. But as you came here, you probably are not so experienced in the submodule area. So better be safe than sorry.


$ git status --porcelain
 M two
$ git submodule deinit two
error: the following file has local modifications:
(use --cached to keep the file, or -f to force removal)
fatal: Submodule work tree 'two' contains local modifications; use '-f' to discard them
$ cd two
$ git submodule deinit --all
error: the following file has local modifications:
(use --cached to keep the file, or -f to force removal)
fatal: Submodule work tree 'md5chk' contains local modifications; use '-f' to discard them
$ cd md5chk
$ git submodule deinit --all
error: the following file has local modifications:
(use --cached to keep the file, or -f to force removal)
fatal: Submodule work tree 'tino' contains local modifications; use '-f' to discard them
$ cd tino
$ git status --porcelain
?? NEW
$ git clean -i -f -d
Would remove the following item:
*** Commands ***
    1: clean                2: filter by pattern    3: select by numbers    4: ask each
    5: quit                 6: help
What now> 1
Removing NEW
$ cd ../../..
$ git status --porcelain
$ git submodule deinit two
Cleared directory 'two'
Submodule 'someunusedname' ( unregistered for path 'two'

You see, there is no -f needed on submodule deinit. If things are clean, in a git clean sense. Also note that git clean -x is not needed. This means git submodule deinit unconditionally removes untracked files which are ignored. This is usually what you want, but do not forget about it. Sometimes ignored files might be precious, like cached data which takes hours to days to be calculated again.

Why never remove $GIT_DIR/modules/<name>/?

Probably people want to remove the cached repository, because they are afraid to run into a problem later. This is true, but running into that "problem" is the correct way to solve it! Because the fix is easy, and done right you will be able to live happily ever after. This avoids more cumbersome trouble than when you remove the data yourself.


mkdir tmptest &&
cd tmptest &&
git init &&
git submodule add two &&
git commit -m . &&
git submodule deinit two &&
git rm two &&
git commit -m . &&
git submodule add two

The last line outputs following error:

A git directory for 'two' is found locally with remote(s):
If you want to reuse this local git directory instead of cloning again from
use the '--force' option. If the local git directory is not the correct repo
or you are unsure what this means choose another name with the '--name' option.

Why this error? Because .git/modules/two/ previously was populated from and now shall be re-populated from something else, namely You won't see this if you re-populate it from

What to do now? Well, just do exactly as told! Use --name someunusedname

git submodule add --name someunusedname two

.gitmodules then looks like

[submodule "someunusedname"]
    path = two
    url =

ls -1p .git/modules/ gives


This way in future you can switch branches/commit forward and backward and will never get into any trouble again, due to two/ having two different (and possibly incompatible) upstream repositories. And the best is: You keep both cached locally, too.

  • This is not only true for you. It also is true for all others using your repository.
  • And you do not lose history. In case you forgot to push the very latest version of the old submodule, you can enter the local copy and do so later on. Note that it is quite common that somebody forgets to push some submodules (because this is a PITA for newcomers, until they became accustomed to git).

However if you removed the cached directory, both different checkouts will stumble upon each other, because you will not use the --name options, right? So each time you do the checkout you perhaps have to remove the .git/modules/<module>/ directory again and again. This is extremely cumbersome and makes it hard to use something like git bisect.

So there is a very technical reason to keep this module directory as a placeholder. People who recommend to remove something below .git/modules/ either do not know better or forget to tell you that this makes powerful features like git bisect nearly impossible to use if this crosses such a submodule incompatibility.

A further reason is shown above. Look at the ls. What do you see there?

Well, the 2nd variant of module two/ is not under .git/modules/two/, it is under .git/modules/someunusedname/! So things like git rm $module; rm -f .git/module/$module are totally wrong! You must either consult module/.git or .gitmodules to find the right thing to remove!

So not only most other answers fall into this dangerous trap, even very popular git extensions had this bug (it's now fixed there)! So better keep your hands of the .git/ directory if you do not exactly, what you are doing!

And from the philosophical view, wiping history is always wrong! Except for quantum mechanics, as usual, but this is something completely different.

FYI you probably guessed it: hilbix is my GitHub account.

MongoDB running but can't connect using shell

I think there is some default config what is missing in this version of mongoDb client. Try to run:


It's strange, but then I've experienced the issue went away :) (so the simple command 'mongo' w/o any params started to work again for me)

[Ubuntu Linux 11.10 x64 / MongoDB 2.0.1]

How to stop tracking and ignore changes to a file in Git?

An almost git command-free approach was given in this answer:

To ignore certain files for every local repo:

  1. Create a file ~/.gitignore_global, e.g. by touch ~/.gitignore_global in your terminal.
  2. Run git config --global core.excludesfile ~/.gitignore_global for once.
  3. Write the file/dir paths you want to ignore into ~/.gitignore_global. e.g. modules/*.H, which will be assumed to be in your working directory, i.e. $WORK_DIR/modules/*.H.

To ignore certain files for a single local repo:

  1. Do the above third step for file .git/info/exclude within the repo, that is write the file/dir paths you want to ignore into .git/info/exclude. e.g. modules/*.C, which will be assumed to be in your working directory, i.e. $WORK_DIR/modules/*.C.


You can still use it (mysqli is just another way of communicating with the server, the SQL language itself is expanded, not changed). Prepared statements are safer, though - since you don't need to go through the trouble of properly escaping your values each time. You can leave them as they were, if you want to but the risk of sql piggybacking is reduced if you switch.

'ls' is not recognized as an internal or external command, operable program or batch file

If you want to use Unix shell commands on Windows, you can use Windows Powershell, which includes both Windows and Unix commands as aliases. You can find more info on it in the documentation.

PowerShell supports aliases to refer to commands by alternate names. Aliasing allows users with experience in other shells to use common command names that they already know for similar operations in PowerShell.

The PowerShell equivalents may not produce identical results. However, the results are close enough that users can do work without knowing the PowerShell command name.

Swift_TransportException Connection could not be established with host

Fatal error: Uncaught exception 'Swift_TransportException' with message 'Connection could not be established with host [Connection refused #111]

Connection refused is a very explicit and clear error message. It means that the socket connection could not be established because the remote end actively refused to connect.

It's very unlikely that Google is blocking the connection.

It's very likely that your web hosting provider has firewall settings that block outgoing connections on port 465, or that they are blocking SMTP to Gmail. 465 is the "wrong" port for secure SMTP, though it is often used, and Gmail does listen there. Try port 587 instead. If the connection is still refused, call your host and ask them what's up.

IFrame: This content cannot be displayed in a frame

The X-Frame-Options is defined in the Http Header and not in the <head> section of the page you want to use in the iframe.

Accepted values are: DENY, SAMEORIGIN and ALLOW-FROM "url"

How to calculate the sentence similarity using word2vec model of gensim with python

Since you're using gensim, you should probably use it's doc2vec implementation. doc2vec is an extension of word2vec to the phrase-, sentence-, and document-level. It's a pretty simple extension, described here

Gensim is nice because it's intuitive, fast, and flexible. What's great is that you can grab the pretrained word embeddings from the official word2vec page and the syn0 layer of gensim's Doc2Vec model is exposed so that you can seed the word embeddings with these high quality vectors!

GoogleNews-vectors-negative300.bin.gz (as linked in Google Code)

I think gensim is definitely the easiest (and so far for me, the best) tool for embedding a sentence in a vector space.

There exist other sentence-to-vector techniques than the one proposed in Le & Mikolov's paper above. Socher and Manning from Stanford are certainly two of the most famous researchers working in this area. Their work has been based on the principle of compositionally - semantics of the sentence come from:

1. semantics of the words

2. rules for how these words interact and combine into phrases

They've proposed a few such models (getting increasingly more complex) for how to use compositionality to build sentence-level representations.

2011 - unfolding recursive autoencoder (very comparatively simple. start here if interested)

2012 - matrix-vector neural network

2013 - neural tensor network

2015 - Tree LSTM

his papers are all available at Some of these models are available, but I'd still recommend gensim's doc2vec. For one, the 2011 URAE isn't particularly powerful. In addition, it comes pretrained with weights suited for paraphrasing news-y data. The code he provides does not allow you to retrain the network. You also can't swap in different word vectors, so you're stuck with 2011's pre-word2vec embeddings from Turian. These vectors are certainly not on the level of word2vec's or GloVe's.

Haven't worked with the Tree LSTM yet, but it seems very promising!

tl;dr Yeah, use gensim's doc2vec. But other methods do exist!

When are you supposed to use escape instead of encodeURI / encodeURIComponent?

The accepted answer is good. To extend on the last part:

Note that encodeURIComponent does not escape the ' character. A common bug is to use it to create html attributes such as href='MyUrl', which could suffer an injection bug. If you are constructing html from strings, either use " instead of ' for attribute quotes, or add an extra layer of encoding (' can be encoded as %27).

If you want to be on the safe side, percent encoding unreserved characters should be encoded as well.

You can use this method to escape them (source Mozilla)

function fixedEncodeURIComponent(str) {
  return encodeURIComponent(str).replace(/[!'()*]/g, function(c) {
    return '%' + c.charCodeAt(0).toString(16);

// fixedEncodeURIComponent("'") --> "%27"

Float a DIV on top of another DIV

I know this post is little bit old but here is a potential solution for anyone who has the same problem:

First, I would change the CSS display for #popup to "none" instead of "hidden".

Second, I would change the HTML as follow:

<div id="overlay-back"></div>
<div id="popup">
    <div style="position: relative;">
        <img class="close-image" src="images/closebtn.png" />
        <span><img src="images/load_sign.png" width="400" height="566" /></span>

And for Style as follow:

   display: block;
   float: right;
   cursor: pointer;
   z-index: 3;
   position: absolute;
   right: 0;
   top: 0;

I got this idea from this website ( A very good example on how to position elements,:

How to position a div on top of another div

I hope this helps,


Better way to cast object to int

var intTried = Convert.ChangeType(myObject, typeof(int)) as int?;

How can I select from list of values in Oracle

Starting from Oracle 12.2, you don't need the TABLE function, you can directly select from the built-in collection.

SQL> select * FROM sys.odcinumberlist(5,2,6,3,78);


SQL> select * FROM sys.odcivarchar2list('A','B','C','D');


Changing element style attribute dynamically using JavaScript

document.getElementById('id').style = 'left: 55%; z-index: 999; overflow: hidden; width: 0px; height: 0px; opacity: 0; display: none;';

works for me

How to enable C++11 in Qt Creator?

If you are using an earlier version of QT (<5) try this

QMAKE_CXXFLAGS += -std=c++0x

Is there a method for String conversion to Title Case?

If you want the correct answer according to the latest Unicode standard, you should use icu4j.

UCharacter.toTitleCase(Locale.US, "hello world", null, 0);

Note that this is locale sensitive.

Api Documentation



If id is sequential starting at 1, the simplest (and quickest) would be:

UPDATE `table` 
SET uid = ELT(id, 2952, 4925, 1592) 
WHERE id IN (1,2,3)

As ELT() returns the Nth element of the list of strings: str1 if N = 1, str2 if N = 2, and so on. Returns NULL if N is less than 1 or greater than the number of arguments.

Clearly, the above code only works if id is 1, 2, or 3. If id was 10, 20, or 30, either of the following would work:

UPDATE `table` 
SET uid = CASE id 
WHEN 10 THEN 2952 
WHEN 20 THEN 4925 
WHERE id IN (10, 20, 30)

or the simpler:

UPDATE `table` 
SET uid = ELT(FIELD(id, 10, 20, 30), 2952, 4925, 1592) 
WHERE id IN (10, 20, 30)

As FIELD() returns the index (position) of str in the str1, str2, str3, ... list. Returns 0 if str is not found.

Exploring Docker container's file system

The most voted answer is good except if your container isn't an actual Linux system.

Many containers (especially the go based ones) don't have any standard binary (no /bin/bash or /bin/sh). In that case, you will need to access the actual containers file directly:

Works like a charm:

dockerId=$(docker inspect -f {{.Id}} $name)
mountId=$(cat /var/lib/docker/image/aufs/layerdb/mounts/$dockerId/mount-id)
cd /var/lib/docker/aufs/mnt/$mountId

Note: You need to run it as root.

How to link HTML5 form action to Controller ActionResult method in ASP.NET MVC 4

Here I'm basically wrapping a button in a link. The advantage is that you can post to different action methods in the same form.

<a href="Controller/ActionMethod">
    <input type="button" value="Click Me" />

Adding parameters:

<a href="Controller/ActionMethod?userName=ted">
    <input type="button" value="Click Me" />

Adding parameters from a non-enumerated Model:

<a href="Controller/[email protected]">
    <input type="button" value="Click Me" />

You can do the same for an enumerated Model too. You would just have to reference a single entity first. Happy Coding!

Having the output of a console application in Visual Studio instead of the console

In the Tools -> Visual Studio Options Dialog -> Debugging -> Check the "Redirect All Output Window Text to the Immediate Window".

Android Studio Gradle Configuration with name 'default' not found

I recently encountered this error when I refereneced a project that was initiliazed via a git submodule.

I ended up finding out that the root build.gradle file of the submodule (a java project) did not have the java plugin applied at the root level.

It only had

apply plugin: 'idea'

I added the java plugin:

apply plugin: 'idea'
apply plugin: 'java'

Once I applied the java plugin the 'default not found' message disappeared and the build succeeded.

What's the HTML to have a horizontal space between two objects?

I guess what you want is:


But this is usually not a nice way to align some content. You better put your different content in


tags and then use css for proper alignment.

You can also check out this post with useful extra info:

Passing a varchar full of comma delimited values to a SQL Server IN function

I've written a stored procedure to show how to do this before. You basically have to process the string. I tried to post the code here but the formatting got all screwy.

IF EXISTS (SELECT * FROM dbo.sysobjects WHERE id = object_id(N'[dbo].[uspSplitTextList]') AND OBJECTPROPERTY(id, N'IsProcedure') = 1)
   DROP PROCEDURE [dbo].[uspSplitTextList]


/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
-- uspSplitTextList
-- Description:
--    splits a separated list of text items and returns the text items
-- Arguments:
--    @list_text        - list of text items
--    @Delimiter        - delimiter
-- Notes:
-- 02/22/2006 - WSR : use DATALENGTH instead of LEN throughout because LEN doesn't count trailing blanks
-- History:
-- 02/22/2006 - WSR : revised algorithm to account for items crossing 8000 character boundary
-- 09/18/2006 - WSR : added to this project
   @list_text           text,
   @Delimiter           varchar(3)


DECLARE @InputLen       integer         -- input text length
DECLARE @TextPos        integer         -- current position within input text
DECLARE @Chunk          varchar(8000)   -- chunk within input text
DECLARE @ChunkPos       integer         -- current position within chunk
DECLARE @DelimPos       integer         -- position of delimiter
DECLARE @ChunkLen       integer         -- chunk length
DECLARE @DelimLen       integer         -- delimiter length
DECLARE @ItemBegPos     integer         -- item starting position in text
DECLARE @ItemOrder      integer         -- item order in list
DECLARE @DelimChar      varchar(1)      -- first character of delimiter (simple delimiter)

-- create table to hold list items
-- actually their positions because we may want to scrub this list eliminating bad entries before substring is applied
CREATE TABLE #list_items ( item_order integer, item_begpos integer, item_endpos integer )

-- process list
IF @list_text IS NOT NULL

   -- initialize
   SET @InputLen = DATALENGTH(@list_text)
   SET @TextPos = 1
   SET @DelimChar = SUBSTRING(@Delimiter, 1, 1)
   SET @DelimLen = DATALENGTH(@Delimiter)
   SET @ItemBegPos = 1
   SET @ItemOrder = 1
   SET @ChunkLen = 1

   -- cycle through input processing chunks
   WHILE @TextPos <= @InputLen AND @ChunkLen <> 0

      -- get current chunk
      SET @Chunk = SUBSTRING(@list_text, @TextPos, 8000)

      -- setup initial variable values
      SET @ChunkPos = 1
      SET @ChunkLen = DATALENGTH(@Chunk)
      SET @DelimPos = CHARINDEX(@DelimChar, @Chunk, @ChunkPos)

      -- loop over the chunk, until the last delimiter
      WHILE @ChunkPos <= @ChunkLen AND @DelimPos <> 0

         -- see if this is a full delimiter
         IF SUBSTRING(@list_text, (@TextPos + @DelimPos - 1), @DelimLen) = @Delimiter

            -- insert position
            INSERT INTO #list_items (item_order, item_begpos, item_endpos)
            VALUES (@ItemOrder, @ItemBegPos, (@TextPos + @DelimPos - 1) - 1)

            -- adjust positions
            SET @ItemOrder = @ItemOrder + 1
            SET @ItemBegPos = (@TextPos + @DelimPos - 1) + @DelimLen
            SET @ChunkPos = @DelimPos + @DelimLen


            -- adjust positions
            SET @ChunkPos = @DelimPos + 1


         -- find next delimiter      
         SET @DelimPos = CHARINDEX(@DelimChar, @Chunk, @ChunkPos)


      -- adjust positions
      SET @TextPos = @TextPos + @ChunkLen


   -- handle last item
   IF @ItemBegPos <= @InputLen

      -- insert position
      INSERT INTO #list_items (item_order, item_begpos, item_endpos)
      VALUES (@ItemOrder, @ItemBegPos, @InputLen)


   -- delete the bad items
   DELETE FROM #list_items
   WHERE item_endpos < item_begpos

   -- return list items
   SELECT SUBSTRING(@list_text, item_begpos, (item_endpos - item_begpos + 1)) AS item_text, item_order, item_begpos, item_endpos
   FROM #list_items
   ORDER BY item_order


DROP TABLE #list_items


/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */


Check if space is in a string

word = ' '
while True:
    if ' ' in word:
        word = raw_input("Please enter a single word: ")
        print "Thanks"

This is more idiomatic python - comparison against True or False is not necessary - just use the value returned by the expression ' ' in word.

Also, you don't need to use pastebin for such a small snippet of code - just copy the code into your post and use the little 1s and 0s button to make your code look like code.

How to pass parameters or arguments into a gradle task

I would suggest the method presented on the Gradle forum:

def createMinifyCssTask(def brand, def sourceFile, def destFile) {
    return tasks.create("minify${brand}Css", com.eriwen.gradle.css.tasks.MinifyCssTask) {
        source = sourceFile
        dest = destFile

I have used this method myself to create custom tasks, and it works very well.

How do I enable MSDTC on SQL Server?

I've found that the best way to debug is to use the microsoft tool called DTCPing

  1. Copy the file to both the server (DB) and the client (Application server/client pc)
    • Start it at the server and the client
    • At the server: fill in the client netbios computer name and try to setup a DTC connection
    • Restart both applications.
    • At the client: fill in the server netbios computer name and try to setup a DTC connection

I've had my fare deal of problems in our old company network, and I've got a few tips:

  • if you get the error message "Gethostbyname failed" it means the computer can not find the other computer by its netbios name. The server could for instance resolve and ping the client, but that works on a DNS level. Not on a netbios lookup level. Using WINS servers or changing the LMHOST (dirty) will solve this problem.
  • if you get an error "Acces Denied", the security settings don't match. You should compare the security tab for the msdtc and get the server and client to match. One other thing to look at is the RestrictRemoteClients value. Depending on your OS version and more importantly the Service Pack, this value can be different.
  • Other connection problems:
    • The firewall between the server and the client must allow communication over port 135. And more importantly the connection can be initiated from both sites (I had a lot of problems with the firewall people in my company because they assumed only the server would open an connection on to that port)
    • The protocol returns a random port to connect to for the real transaction communication. Firewall people don't like that, they like to restrict the ports to a certain range. You can restrict the RPC dynamic port generation to a certain range using the keys as described in How to configure RPC dynamic port allocation to work with firewalls.

In my experience, if the DTCPing is able to setup a DTC connection initiated from the client and initiated from the server, your transactions are not the problem any more.

Data access object (DAO) in Java

DAO is an act like as "Persistence Manager " in 3 tier architecture as well as DAO also design pattern as you can consult "Gang of Four" book. Your application service layer just need to call the method of DAO class without knowing hidden & internal details of DAO's method.

Parsing a YAML file in Python, and accessing the data?

Since PyYAML's yaml.load() function parses YAML documents to native Python data structures, you can just access items by key or index. Using the example from the question you linked:

import yaml
with open('tree.yaml', 'r') as f:
    doc = yaml.load(f)

To access branch1 text you would use:

txt = doc["treeroot"]["branch1"]
print txt
"branch1 text"

because, in your YAML document, the value of the branch1 key is under the treeroot key.

How to get the number of days of difference between two dates on mysql?

Use the DATEDIFF() function.

Example from documentation:

SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30');
    -> 1

In C - check if a char exists in a char array

You want

strchr (const char *s, int c)

If the character c is in the string s it returns a pointer to the location in s. Otherwise it returns NULL. So just use your list of invalid characters as the string.

how to make log4j to write to the console as well

Write the root logger as below for logging on both console and FILE


And write the respective definitions like Target, Layout, and ConversionPattern (MaxFileSize for file etc).

How to get table cells evenly spaced?

Make a surrounding div-tag, and set for it display: grid in its style attribute.

<div style='display: grid; 
            text-align: center;
            background-color: antiquewhite'

The text-align property is set only to show, that the text in the regular table cells are affected by it, even though it is set on the surrounding div. The same with the background-color but it is hard to say which element actually holds the background-color.

How can I export the schema of a database in PostgreSQL?

For Linux: (data excluded)

  • pg_dump -s -t tablename databasename > dump.sql (For a specific table in database)

  • pg_dump -s databasename > dump.sql (For the entire database)

How to extract this specific substring in SQL Server?

Assuming they always exist and are not part of your data, this will work:

declare @string varchar(8000) = '23;chair,red [$3]'
select substring(@string, charindex(';', @string) + 1, charindex(' [', @string) - charindex(';', @string) - 1)

Return value in a Bash function

$(...) captures the text sent to stdout by the command contained within. return does not output to stdout. $? contains the result code of the last command.

fun1 (){
  return 34

fun2 (){
  local res=$?
  echo $res

Browse for a directory in C#

string folderPath = "";
FolderBrowserDialog folderBrowserDialog1 = new FolderBrowserDialog();
if (folderBrowserDialog1.ShowDialog() == DialogResult.OK) {
    folderPath = folderBrowserDialog1.SelectedPath ;

How do I update a formula with Homebrew?

You can't use brew install to upgrade an installed formula. If you want upgrade all of outdated formulas, you can use the command below.

brew outdated | xargs brew upgrade

Delaying a jquery script until everything else has loaded

This code block solve my problem,

<script type="text/javascript">_x000D_
  $(window).bind("load", function () {_x000D_
    // Code here_x000D_

How to use addTarget method in swift 3

Try with swift 3

cell.TaxToolTips.tag = indexPath.row
        cell.TaxToolTips.addTarget(self, action: #selector(InheritanceTaxViewController.displayToolTipDetails(_:)), for:.touchUpInside)

 @objc func displayToolTipDetails(_ sender : UIButton) {
        let tooltipString = TaxToolTipsArray[sender.tag]
        self.displayMyAlertMessage(userMessage: tooltipString, status: 202)    

col align right

For The Bootstrap 4+

This Code Worked Well for me

<div class="row">
        <div class="col">
            <div class="ml-auto">
                this content will be in the Right
        <div class="col mr-auto">
            <div class="mr-auto">
                this content will be in the leftt

Static Initialization Blocks

Here's an example:

  private static final HashMap<String, String> MAP = new HashMap<String, String>();
  static {
    MAP.put("banana", "honey");
    MAP.put("peanut butter", "jelly");
    MAP.put("rice", "beans");

The code in the "static" section(s) will be executed at class load time, before any instances of the class are constructed (and before any static methods are called from elsewhere). That way you can make sure that the class resources are all ready to use.

It's also possible to have non-static initializer blocks. Those act like extensions to the set of constructor methods defined for the class. They look just like static initializer blocks, except the keyword "static" is left off.

How to run PyCharm in Ubuntu - "Run in Terminal" or "Run"?

The question is already answered, Updating answer to add the PyCharm bin directory to $PATH var, so that pycharm editor can be opened from anywhere(path) in terminal.

Edit the bashrc file,

nano .bashrc

Add following line at the end of bashrc file

export PATH="<path-to-unpacked-pycharm-installation-directory>/bin:$PATH"

Now you can open pycharm from anywhere in terminal

How to set default values for Angular 2 component properties?

That is interesting subject. You can play around with two lifecycle hooks to figure out how it works: ngOnChanges and ngOnInit.

Basically when you set default value to Input that's mean it will be used only in case there will be no value coming on that component. And the interesting part it will be changed before component will be initialized.

Let's say we have such components with two lifecycle hooks and one property coming from input.

  selector: 'cmp',
export class Login implements OnChanges, OnInit {
  @Input() property: string = 'default';

  ngOnChanges(changes) {

  ngOnInit() {


Situation 1

Component included in html without defined property value

As result we will see in console: Init default

That's mean onChange was not triggered. Init was triggered and property value is default as expected.

Situation 2

Component included in html with setted property <cmp [property]="'new value'"></cmp>

As result we will see in console:

Changed new value Object {}

Init new value

And this one is interesting. Firstly was triggered onChange hook, which setted property to new value, and previous value was empty object! And only after that onInit hook was triggered with new value of property.

How can I make Bootstrap columns all the same height?

I'm surprised I couldn't find a worthwhile solution here late 2018. I went ahead and figured it out a Bootstrap 3 solution myself using flexbox.

Clean and simple example:

Example of matched column widths in Bootstrap 3


<div class="row row-equal">
    <div class="col-lg-4 col-md-4 col-sm-4 col-xs-12 col-equal">
    <div class="col-lg-4 col-md-4 col-sm-4 col-xs-12 col-equal">
        <img src="//">
    <div class="col-lg-4 col-md-4 col-sm-4 col-xs-12 col-equal">


img {
  width: 100%;
p {
  padding: 2em;
@media (min-width: 768px) {
  .row-equal {
    display: flex;
    flex-wrap: wrap;
  .col-equal {
    margin: auto;

View working demo:

SQLite select where empty?

There are several ways, like:

where some_column is null or some_column = ''


where ifnull(some_column, '') = ''


where coalesce(some_column, '') = ''


where ifnull(length(some_column), 0) = 0

Query to select data between two dates with the format m/d/yyyy

DateTime dt1 = this.dateTimePicker1.Value.Date;
DateTime dt2 = this.dateTimePicker2.Value.Date.AddMinutes(1440);
String query = "SELECT * FROM student WHERE sdate BETWEEN '" + dt1 + "' AND '" + dt2 + "'";

I want to declare an empty array in java and then I want do update it but the code is not working

Your code compiles just fine. However, your array initialization line is wrong:

int array[]={};

What this does is declare an array with a size equal to the number of elements in the brackets. Since there is nothing in the brackets, you're saying the size of the array is 0 - this renders the array completely useless, since now it can't store anything.

Instead, you can either initialize the array right in your original line:

int array[] = { 5, 5, 5, 5 };

Or you can declare the size and then populate it:

int array[] = new int[4];
// ...while loop

If you don't know the size of the array ahead of time (for example, if you're reading a file and storing the contents), you should use an ArrayList instead, because that's an array that grows in size dynamically as more elements are added to it (in layman's terms).

How to include multiple js files using jQuery $.getScript() method

This works for me:

function getScripts(scripts) {
    var prArr = [];
    scripts.forEach(function(script) { 
            prArr .push(new Promise(function(resolve){
                $.getScript(script, function () {
    return Promise.all(prArr, function(){
        return true;

And use it:

var jsarr = ['script1.js','script2.js'];

JFrame Maximize window

@kgiannakakis answer is fully correct, but if someone stuck into this problem and uses Java 6 on Linux (by example, Mint 19 Cinnamon), MAXIMIZED_BOTH state is sometimes not applied.

You could try to call pack() method after setting this state.

Code example:

public MainFrame() {
    setContentPane(contentPanel); //some JPanel is here
    setPreferredSize(new Dimension(1200, 800));
    setMinimumSize(new Dimension(1200, 800));
    setSize(new Dimension(1200, 800));

This is not necessary if you are using Java 7+ or Java 6 on Windows.

window.onload vs <body onload=""/>

window.onload = myOnloadFunc and <body onload="myOnloadFunc();"> are different ways of using the same event. Using window.onload is less obtrusive though - it takes your JavaScript out of the HTML.

All of the common JavaScript libraries, Prototype, ExtJS, Dojo, JQuery, YUI, etc. provide nice wrappers around events that occur as the document is loaded. You can listen for the window onLoad event, and react to that, but onLoad is not fired until all resources have been downloaded, so your event handler won't be executed until that last huge image has been fetched. In some cases that's exactly what you want, in others you might find that listening for when the DOM is ready is more appropriate - this event is similar to onLoad but fires without waiting for images, etc. to download.

Catch a thread's exception in the caller thread in Python

I know I'm a bit late to the party here but I was having a very similar problem but it included using tkinter as a GUI, and the mainloop made it impossible to use any of the solutions that depend on .join(). Therefore I adapted the solution given in the EDIT of the original question, but made it more general to make it easier to understand for others.

Here is the new thread class in action:

import threading
import traceback
import logging

class ExceptionThread(threading.Thread):
    def __init__(self, *args, **kwargs):
        threading.Thread.__init__(self, *args, **kwargs)

    def run(self):
            if self._target:
                self._target(*self._args, **self._kwargs)
        except Exception:

def test_function_1(input):
    raise IndexError(input)

if __name__ == "__main__":
    input = 'useful'

    t1 = ExceptionThread(target=test_function_1, args=[input])

Of course you can always have it handle the exception some other way from logging, such as printing it out, or having it output to the console.

This allows you to use the ExceptionThread class exactly like you would the Thread class, without any special modifications.

How to tell if UIViewController's view is visible

The view's window property is non-nil if a view is currently visible, so check the main view in the view controller:

Invoking the view method causes the view to load (if it is not loaded) which is unnecessary and may be undesirable. It would be better to check first to see if it is already loaded. I've added the call to isViewLoaded to avoid this problem.

if (viewController.isViewLoaded && viewController.view.window) {
    // viewController is visible

Since iOS9 it has became easier:

if viewController.viewIfLoaded?.window != nil {
    // viewController is visible

Or if you have a UINavigationController managing the view controllers, you could check its visibleViewController property instead.

"Cannot update paths and switch to branch at the same time"

You can use these commands: git remote update, git fetch, git checkout -b branch_nameA origin:branch_nameB

I think maybe it's because of your local branch can not track remote branch

VBA changing active workbook

Use ThisWorkbook which will refer to the original workbook which holds the code.

Alternatively at code start

Dim Wb As Workbook
Set Wb = ActiveWorkbook

sample code that activates all open books before returning to ThisWorkbook

Sub Test()
Dim Wb As Workbook
Dim Wb2 As Workbook
Set Wb = ThisWorkbook
For Each Wb2 In Application.Workbooks
End Sub

export html table to csv

I used Calumah's function posted above, but I did run into an issue with his code as poisted.

The rows are joined with a semicolon


but the link generated has "text/csv" as the content type

Maybe in Windows that isn't a problem, but in Excel for Mac that throws things off. I changed the array join to a comma and it worked perfect.

Pandas column of lists, create a row for each list element

I found the easiest way was to:

  1. Convert the samples column into a DataFrame
  2. Joining with the original df
  3. Melting

Shown here:

    df.samples.apply(lambda x: pd.Series(x)).join(df).\

        subject  trial_num sample  value
    0         1          1      0  -0.24
    1         1          2      0   0.14
    2         1          3      0  -0.67
    3         2          1      0  -1.52
    4         2          2      0  -0.00
    5         2          3      0  -1.73
    6         1          1      1  -0.70
    7         1          2      1  -0.70
    8         1          3      1  -0.29
    9         2          1      1  -0.70
    10        2          2      1  -0.72
    11        2          3      1   1.30
    12        1          1      2  -0.55
    13        1          2      2   0.10
    14        1          3      2  -0.44
    15        2          1      2   0.13
    16        2          2      2  -1.44
    17        2          3      2   0.73

It's worth noting that this may have only worked because each trial has the same number of samples (3). Something more clever may be necessary for trials of different sample sizes.

Get Element value with minidom with Python

Probably something like this if it's the text part you want...

from xml.dom.minidom import parse
dom = parse("C:\\eve.xml")
name = dom.getElementsByTagName('name')

print " ".join(t.nodeValue for t in name[0].childNodes if t.nodeType == t.TEXT_NODE)

The text part of a node is considered a node in itself placed as a child-node of the one you asked for. Thus you will want to go through all its children and find all child nodes that are text nodes. A node can have several text nodes; eg.


You want both 'blabla' and 'znylpx'; hence the " ".join(). You might want to replace the space with a newline or so, or perhaps by nothing.

Do fragments really need an empty constructor?

Here is my simple solution:

1 - Define your fragment

public class MyFragment extends Fragment {

    private String parameter;

    public MyFragment() {

    public void setParameter(String parameter) {
        this.parameter = parameter;

2 - Create your new fragment and populate the parameter

    myfragment = new MyFragment();
    myfragment.setParameter("here the value of my parameter");

3 - Enjoy it!

Obviously you can change the type and the number of parameters. Quick and easy.

Copy data from one existing row to another existing row in SQL?

Copy a value from one row to any other qualified rows within the same table (or different tables):

UPDATE `your_table` t1, `your_table` t2
SET t1.your_field = t2.your_field
WHERE t1.other_field = some_condition
AND t1.another_field = another_condition
AND t2.source_id = 'explicit_value'

Start off by aliasing the table into 2 unique references so the SQL server can tell them apart

Next, specify the field(s) to copy.

Last, specify the conditions governing the selection of the rows

Depending on the conditions you may copy from a single row to a series, or you may copy a series to a series. You may also specify different tables, and you can even use sub-selects or joins to allow using other tables to control the relationships.

What's the difference between ".equals" and "=="?

(1) == can be be applied for both primitives and object types, but equals() method can be applied for only object types.

(2) == cannot be overridden for content comparison, but equals method can be overridden for content comparison(ex; String class, wrapper classes, collection classes).

(3) == gives incomparable types error when try to apply for heterogeneous types , where as equals method returns false.

Lambda function in list comprehensions

This question touches a very stinking part of the "famous" and "obvious" Python syntax - what takes precedence, the lambda, or the for of list comprehension.

I don't think the purpose of the OP was to generate a list of squares from 0 to 9. If that was the case, we could give even more solutions:

squares = []
for x in range(10): squares.append(x*x)
  • this is the good ol' way of imperative syntax.

But it's not the point. The point is W(hy)TF is this ambiguous expression so counter-intuitive? And I have an idiotic case for you at the end, so don't dismiss my answer too early (I had it on a job interview).

So, the OP's comprehension returned a list of lambdas:

[(lambda x: x*x) for x in range(10)]

This is of course just 10 different copies of the squaring function, see:

>>> [lambda x: x*x for _ in range(3)]
[<function <lambda> at 0x00000000023AD438>, <function <lambda> at 0x00000000023AD4A8>, <function <lambda> at 0x00000000023AD3C8>]

Note the memory addresses of the lambdas - they are all different!

You could of course have a more "optimal" (haha) version of this expression:

>>> [lambda x: x*x] * 3
[<function <lambda> at 0x00000000023AD2E8>, <function <lambda> at 0x00000000023AD2E8>, <function <lambda> at 0x00000000023AD2E8>]

See? 3 time the same lambda.

Please note, that I used _ as the for variable. It has nothing to do with the x in the lambda (it is overshadowed lexically!). Get it?

I'm leaving out the discussion, why the syntax precedence is not so, that it all meant:

[lambda x: (x*x for x in range(10))]

which could be: [[0, 1, 4, ..., 81]], or [(0, 1, 4, ..., 81)], or which I find most logical, this would be a list of 1 element - a generator returning the values. It is just not the case, the language doesn't work this way.

BUT What, If...

What if you DON'T overshadow the for variable, AND use it in your lambdas???

Well, then crap happens. Look at this:

[lambda x: x * i for i in range(4)]

this means of course:

[(lambda x: x * i) for i in range(4)]

BUT it DOESN'T mean:

[(lambda x: x * 0), (lambda x: x * 1), ... (lambda x: x * 3)]

This is just crazy!

The lambdas in the list comprehension are a closure over the scope of this comprehension. A lexical closure, so they refer to the i via reference, and not its value when they were evaluated!

So, this expression:

[(lambda x: x * i) for i in range(4)]

IS roughly EQUIVALENT to:

[(lambda x: x * 3), (lambda x: x * 3), ... (lambda x: x * 3)]

I'm sure we could see more here using a python decompiler (by which I mean e.g. the dis module), but for Python-VM-agnostic discussion this is enough. So much for the job interview question.

Now, how to make a list of multiplier lambdas, which really multiply by consecutive integers? Well, similarly to the accepted answer, we need to break the direct tie to i by wrapping it in another lambda, which is getting called inside the list comprehension expression:


>>> a = [(lambda x: x * i) for i in (1, 2)]
>>> a[1](1)
>>> a[0](1)


>>> a = [(lambda y: (lambda x: y * x))(i) for i in (1, 2)]
>>> a[1](1)
>>> a[0](1)

(I had the outer lambda variable also = i, but I decided this is the clearer solution - I introduced y so that we can all see which witch is which).

Edit 2019-08-30:

Following a suggestion by @josoler, which is also present in an answer by @sheridp - the value of the list comprehension "loop variable" can be "embedded" inside an object - the key is for it to be accessed at the right time. The section "After" above does it by wrapping it in another lambda and calling it immediately with the current value of i. Another way (a little bit easier to read - it produces no 'WAT' effect) is to store the value of i inside a partial object, and have the "inner" (original) lambda take it as an argument (passed supplied by the partial object at the time of the call), i.e.:

After 2:

>>> from functools import partial
>>> a = [partial(lambda y, x: y * x, i) for i in (1, 2)]
>>> a[0](2), a[1](2)
(2, 4)

Great, but there is still a little twist for you! Let's say we wan't to make it easier on the code reader, and pass the factor by name (as a keyword argument to partial). Let's do some renaming:

After 2.5:

>>> a = [partial(lambda coef, x: coef * x, coef=i) for i in (1, 2)]
>>> a[0](1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: <lambda>() got multiple values for argument 'coef'


>>> a[0]()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: <lambda>() missing 1 required positional argument: 'x'

Wait... We're changing the number of arguments by 1, and going from "too many" to "too few"?

Well, it's not a real WAT, when we pass coef to partial in this way, it becomes a keyword argument, so it must come after the positional x argument, like so:

After 3:

>>> a = [partial(lambda x, coef: coef * x, coef=i) for i in (1, 2)]
>>> a[0](2), a[1](2)
(2, 4)

I would prefer the last version over the nested lambda, but to each their own...

Edit 2020-08-18:

Thanks to commenter dasWesen, I found out that this stuff is covered in the Python documentation: - it deals with loops instead of list comprehensions, but the idea is the same - global or nonlocal variable access in the lambda function. There's even a solution - using default argument values (like for any function):

>>> a = [lambda x, coef=i: coef * x for i in (1, 2)]
>>> a[0](2), a[1](2)
(2, 4)

This way the coef value is bound to the value of i at the time of function definition (see James Powell's talk "Top To Down, Left To Right", which also explains why mutable default values are shunned).

Convert String with Dot or Comma as decimal separator to number in JavaScript

This answer accepts some edge cases that others don't:

  • Only thousand separator: 1.000.000 => 1000000
  • Exponentials: 1.000e3 => 1000e3 (1 million)

Run the code snippet to see all the test suite.

const REGEX_UNWANTED_CHARACTERS = /[^\d\-.,]/g
const REGEX_PERIODS_EXEPT_LAST = /\.(?=.*\.)/g

export function formatNumber(number) {
  // Handle exponentials
  if ((number.match(/e/g) ?? []).length === 1) {
    const numberParts = number.split('e')
    return `${formatNumber(numberParts[0])}e${formatNumber(numberParts[1])}`

  const sanitizedNumber = number

  // Handle only thousands separator
  if (
    ((sanitizedNumber.match(/,/g) ?? []).length >= 2 && !sanitizedNumber.includes('.')) ||
    ((sanitizedNumber.match(/\./g) ?? []).length >= 2 && !sanitizedNumber.includes(','))
  ) {
    return sanitizedNumber.replace(/[.,]/g, '')

  return sanitizedNumber.replace(/,/g, '.').replace(REGEX_PERIODS_EXEPT_LAST, '')

function formatNumberToNumber(number) {
  return Number(formatNumber(number))

const REGEX_UNWANTED_CHARACTERS = /[^\d\-.,]/g
const REGEX_PERIODS_EXEPT_LAST = /\.(?=.*\.)/g

function formatNumber(number) {
  if ((number.match(/e/g) ?? []).length === 1) {
    const numberParts = number.split('e')
    return `${formatNumber(numberParts[0])}e${formatNumber(numberParts[1])}`

  const sanitizedNumber = number

  if (
    ((sanitizedNumber.match(/,/g) ?? []).length >= 2 && !sanitizedNumber.includes('.')) ||
    ((sanitizedNumber.match(/\./g) ?? []).length >= 2 && !sanitizedNumber.includes(','))
  ) {
    return sanitizedNumber.replace(/[.,]/g, '')

  return sanitizedNumber.replace(/,/g, '.').replace(REGEX_PERIODS_EXEPT_LAST, '')

const testCases = [




document.getElementById('tbody').innerHTML = testCases.reduce((total, input) => {
  return `${total}<tr><td>${input}</td><td>${formatNumber(input)}</td></tr>`
}, '')
  <tbody id="tbody"></tbody>

How can I get the value of a registry key from within a batch script?

Thanks, i just need to use:

SETLOCAL EnableExtensions

And put a:


Into the REG QUERY called in the FOR command. Thanks a lot again! :)

Run Jquery function on window events: load, resize, and scroll?

just call your function inside the events.


$(document).ready(function(){  // or  $(window).load(function(){


$(window).resize(function () {


$(window).scroll(function () {

or bind all event in one function

$(window).on("load scroll resize",function(e){

how to set ul/li bullet point color?

A couple ways this can be done:

This will make it a square

  list-style-type: square;

This will make it green

  color: #0F0;

This will prevent the text from being green

li p
  color: #000;

However that will require that all text within lists be in paragraphs so that the color is not overridden.

A better way is to make an image of a green square and use:

  list-style: url(green-square.png);

Generating 8-character only UUIDs

It is not possible since a UUID is a 16-byte number per definition. But of course, you can generate 8-character long unique strings (see the other answers).

Also be careful with generating longer UUIDs and substring-ing them, since some parts of the ID may contain fixed bytes (e.g. this is the case with MAC, DCE and MD5 UUIDs).

Oracle SQL - DATE greater than statement

you have to use the To_Date() function to convert the string to date !

Can you "compile" PHP code and upload a binary-ish file, which will just be run by the byte code interpreter?

PHP doesn't really get compiled as with many programs. You can use Zend's encoder to make it unreadable though.

Space between two rows in a table?

since I have a background image behind the table, faking it with white padding wouldn't work. I opted to put an empty row in-between each row of content:

<tr class="spacer"><td></td></tr>

then use css to give the spacer rows a certain height and transparent background.

#include errors detected in vscode

  • Left mouse click on the bulb of error line
  • Click Edit Include path
  • Then this window popup

enter image description here

  • Just set Compiler path

npm throws error without sudo

Changing the owner on "system-global" folders is a hack. On a fresh install, I would configure NPM to use an already writable location for "user-global" programs:

npm config set prefix ~/npm

Then make sure you add that folder to your path:

export PATH="$PATH:$HOME/npm/bin"

See @ErikAndreas' answer to NPM modules won't install globally without sudo and longer step-by-step guide by @sindresorhus with also sets $MANPATH.

List of lists into numpy array

If your list of lists contains lists with varying number of elements then the answer of Ignacio Vazquez-Abrams will not work. Instead there are at least 3 options:

1) Make an array of arrays:

y=numpy.array([numpy.array(xi) for xi in x])
>>><type 'numpy.ndarray'>
>>><type 'numpy.ndarray'>

2) Make an array of lists:

>>><type 'numpy.ndarray'>
>>><type 'list'>

3) First make the lists equal in length:

length = max(map(len, x))
y=numpy.array([xi+[None]*(length-len(xi)) for xi in x])
>>>array([[1, 2, None],
>>>       [1, 2, 3],
>>>       [1, None, None]], dtype=object)

Authentication issue when debugging in VS2013 - iis express

As I was researching this I found my answer, but can't find the answer on the internet, so I thought I'd share this:

I fixed my issue by modifying my applicationhost.config file. My file was saved in the "\My Documents\IISExpress\config" folder.

It seems that VS2013 was ignoring my web.config file and applying different authentication methods.

I had to modify this portion of the file to look like the below. In truth, I only modified the anonymousAuthentication to be false and the windowsAuthentication mode to true.


  <anonymousAuthentication enabled="false" userName="" />

  <basicAuthentication enabled="false" />

  <clientCertificateMappingAuthentication enabled="false" />

  <digestAuthentication enabled="false" />

  <iisClientCertificateMappingAuthentication enabled="false">

  <windowsAuthentication enabled="true">
      <add value="Negotiate" />
      <add value="NTLM" />


What is the current directory in a batch file?

Your bat file should be in the directory that the bat file is/was in when you opened it. However if you want to put it into a different directory you can do so with cd [whatever directory]

Explain ExtJS 4 event handling

Just wanted to add a couple of pence to the excellent answers above: If you are working on pre Extjs 4.1, and don't have application wide events but need them, I've been using a very simple technique that might help: Create a simple object extending Observable, and define any app wide events you might need in it. You can then fire those events from anywhere in your app, including actual html dom element and listen to them from any component by relaying the required elements from that component.

Ext.define('Lib.MessageBus', {
    extend: 'Ext.util.Observable',

    constructor: function() {
             * describe the event


Then you can, from any other component:

 this.relayEvents(MesageBus, ['event1', 'event2'])

And fire them from any component or dom element:

 MessageBus.fireEvent('event1', somearg);

 <input type="button onclick="MessageBus.fireEvent('event2', 'somearg')">

How to load a resource from WEB-INF directory of a web archive

Here is how it works for me with no Servlet use.

Let's say I am trying to access web.xml in project/WebContent/WEB-INF/web.xml

  1. In project property Source-tab add source folder by pointing to the parent container for WEB-INF folder (in my case WebContent )

  2. Now let's use class loader:

    InputStream inStream = class.getClass().getClassLoader().getResourceAsStream("Web-INF/web.xml")

how to check the version of jar file?

I'm late this but you can try the following two methods

using these needed classes

import java.util.jar.Attributes;
import java.util.jar.Manifest;

These methods let me access the jar attributes. I like being backwards compatible and use the latest. So I used this

public Attributes detectClassBuildInfoAttributes(Class sourceClass) throws MalformedURLException, IOException {
    String className = sourceClass.getSimpleName() + ".class";
    String classPath = sourceClass.getResource(className).toString();
    if (!classPath.startsWith("jar")) {
      // Class not from JAR
      return null;
    String manifestPath = classPath.substring(0, classPath.lastIndexOf("!") + 1) + 
    Manifest manifest = new Manifest(new URL(manifestPath).openStream());
    return manifest.getEntries().get("Build-Info");

public String retrieveClassInfoAttribute(Class sourceClass, String attributeName) throws MalformedURLException, IOException {
    Attributes version_attr = detectClassBuildInfoAttributes(sourceClass);

    String attribute = version_attr.getValue(attributeName);

    return attribute;

This works well when you are using maven and need pom details for known classes. Hope this helps.

Find the nth occurrence of substring in a string

Simplest way?

text = "This is a test from a test ok" 

firstTest = text.find('test')

print text.find('test', firstTest + 1)

Angular 4 - get input value

You can use (keyup) or (change) events, see example below:

in HTML:

<input (keyup)="change($event)">


<input (change)="change($event)">

in Component:

change(event) {console.log(;}

How to find all duplicate from a List<string>?

For what it's worth, here is my way:

List<string> list = new List<string>(new string[] { "cat", "Dog", "parrot", "dog", "parrot", "goat", "parrot", "horse", "goat" });
Dictionary<string, int> wordCount = new Dictionary<string, int>();

//count them all:
list.ForEach(word =>
    string key = word.ToLower();
    if (!wordCount.ContainsKey(key))
        wordCount.Add(key, 0);

//remove words appearing only once:
wordCount.Keys.ToList().FindAll(word => wordCount[word] == 1).ForEach(key => wordCount.Remove(key));

Console.WriteLine(string.Format("Found {0} duplicates in the list:", wordCount.Count));
wordCount.Keys.ToList().ForEach(key => Console.WriteLine(string.Format("{0} appears {1} times", key, wordCount[key])));

How to use regex in XPath "contains" function

If you're using Selenium with Firefox you should be able to use EXSLT extensions, and regexp:test()

Does this work for you?

String expr = "//*[regexp:test(@id, 'sometext[0-9]+_text')]";

How to write a Python module/package?

A module is a file containing Python definitions and statements. The file name is the module name with the suffix .py

create then write the following function as its content:

def helloworld():
   print "hello"

Then you can import hello:

>>> import hello
>>> hello.helloworld()

To group many .py files put them in a folder. Any folder with an is considered a module by python and you can call them a package


You can go about with the import statement on your module the usual way.

For more information, see 6.4. Packages.

Is there a command to restart computer into safe mode?

In the command prompt, type the command below and press Enter.

bcdedit /enum

Under the Windows Boot Loader sections, make note of the identifier value.

To start in safe mode from command prompt :

bcdedit /set {identifier} safeboot minimal 

Then enter the command line to reboot your computer.

Set initially selected item in Select list in Angular2

Update to angular 4.X.X, there is a new way to mark an option selected:

<select [compareWith]="byId" [(ngModel)]="selectedItem">
  <option *ngFor="let item of items" [ngValue]="item">{{}}

byId(item1: ItemModel, item2: ItemModel) {
  return ===;

Some tutorial here

How to hash a string into 8 digits?

Yes, you can use the built-in hashlib module or the built-in hash function. Then, chop-off the last eight digits using modulo operations or string slicing operations on the integer form of the hash:

>>> s = 'she sells sea shells by the sea shore'

>>> # Use hashlib
>>> import hashlib
>>> int(hashlib.sha1(s.encode("utf-8")).hexdigest(), 16) % (10 ** 8)

>>> # Use hash()
>>> abs(hash(s)) % (10 ** 8)

How to create a file in a directory in java?

The best way to do it is:

String path = "C:" + File.separator + "hello" + File.separator + "hi.txt";
// Use relative path for Unix systems
File f = new File(path);


Can I try/catch a warning?

Be careful with the @ operator - while it suppresses warnings it also suppresses fatal errors. I spent a lot of time debugging a problem in a system where someone had written @mysql_query( '...' ) and the problem was that mysql support was not loaded into PHP and it threw a silent fatal error. It will be safe for those things that are part of the PHP core but please use it with care.

bob@mypc:~$ php -a
Interactive shell

php > echo @something(); // this will just silently die...

No further output - good luck debugging this!

bob@mypc:~$ php -a
Interactive shell

php > echo something(); // lets try it again but don't suppress the error
PHP Fatal error:  Call to undefined function something() in php shell code on line 1
PHP Stack trace:
PHP   1. {main}() php shell code:0

This time we can see why it failed.

jQuery posting JSON

In case you are sending this post request to a cross domain, you should check out this link.

Your server is not accepting the cross site post request. So the server configuration needs to be changed to allow cross site requests.

How to perform a sum of an int[] array

Here is an efficient way to solve this question using For loops in Java

 public static void main(String[] args) {

    int [] numbers = { 1, 2, 3, 4 };
    int size = numbers.length;

    int sum = 0;
    for (int i = 0; i < size; i++) {
        sum += numbers[i];


How To Inject AuthenticationManager using Java Configuration in a Custom Filter

Override method authenticationManagerBean in WebSecurityConfigurerAdapter to expose the AuthenticationManager built using configure(AuthenticationManagerBuilder) as a Spring bean:

For example:

   public AuthenticationManager authenticationManagerBean() throws Exception {
       return super.authenticationManagerBean();

Figuring out whether a number is a Double in Java

Since this is the first question from Google I'll add the JavaScript style typeof alternative here as well:

myObject.getClass().getName() // String

TypeError: Converting circular structure to JSON in nodejs

I came across this issue when not using async/await on a asynchronous function (api call). Hence adding them / using the promise handlers properly cleared the error.

React eslint error missing in props validation

It seems that the problem is in eslint-plugin-react.

It can not correctly detect what props were mentioned in propTypes if you have annotated named objects via destructuring anywhere in the class.

There was similar problem in the past

In Tensorflow, get the names of all the Tensors in a graph

Previous answers are good, I'd just like to share a utility function I wrote to select Tensors from a graph:

def get_graph_op(graph, and_conds=None, op='and', or_conds=None):
    """Selects nodes' names in the graph if:
    - The name contains all items in and_conds
    - OR/AND depending on op
    - The name contains any item in or_conds

    Condition starting with a "!" are negated.
    Returns all ops if no optional arguments is given.

        graph (tf.Graph): The graph containing sought tensors
        and_conds (list(str)), optional): Defaults to None.
            "and" conditions
        op (str, optional): Defaults to 'and'. 
            How to link the and_conds and or_conds:
            with an 'and' or an 'or'
        or_conds (list(str), optional): Defaults to None.
            "or conditions"

        list(str): list of relevant tensor names
    assert op in {'and', 'or'}

    if and_conds is None:
        and_conds = ['']
    if or_conds is None:
        or_conds = ['']

    node_names = [ for n in graph.as_graph_def().node]

    ands = {
        n for n in node_names
        if all(
            cond in n if '!' not in cond
            else cond[1:] not in n
            for cond in and_conds

    ors = {
        n for n in node_names
        if any(
            cond in n if '!' not in cond
            else cond[1:] not in n
            for cond in or_conds

    if op == 'and':
        return [
            n for n in node_names
            if n in ands.intersection(ors)
    elif op == 'or':
        return [
            n for n in node_names
            if n in ands.union(ors)

So if you have a graph with ops:


Then running

get_graph_op(tf.get_default_graph(), ['dense', '!kernel'], 'or', ['Assign'])



Error parsing XHTML: The content of elements must consist of well-formed character data or markup

Facelets is a XML based view technology which uses XHTML+XML to generate HTML output. XML has five special characters which has special treatment by the XML parser:

  • < the start of a tag.
  • > the end of a tag.
  • " the start and end of an attribute value.
  • ' the alternative start and end of an attribute value.
  • & the start of an entity (which ends with ;).

In case of <, the XML parser is implicitly looking for the tag name and the end tag >. However, in your particular case, you were using < as a JavaScript operator, not as an XML entity. This totally explains the XML parsing error you got:

The content of elements must consist of well-formed character data or markup.

In essence, you're writing JavaScript code in the wrong place, a XML document instead of a JS file, so you should be escaping all XML special characters accordingly. The < must be escaped as &lt;.

So, essentially, the

for (var i = 0; i < length; i++) {

must become

for (var i = 0; i &lt; length; i++) {

to make it XML-valid.

However, this makes the JavaScript code harder to read and maintain. As stated in Mozilla Developer Network's excellent document Writing JavaScript for XHTML, you should be placing the JavaScript code in a character data (CDATA) block. Thus, in JSF terms, that would be:

        // ...

The XML parser will interpret the block's contents as "plain vanilla" character data and not as XML and hence interpret the XML special characters "as-is".

But, much better is to just put the JS code in its own JS file which you include by <script src>, or in JSF terms, the <h:outputScript>.

<h:outputScript name="functions.js" target="head" />

This way you don't need to worry about XML-special characters in your JS code. Additional advantage is that this gives the browser the opportunity to cache the JS file so that average response size is smaller.

See also:

Why are the Level.FINE logging messages not showing?


As mentioned by @Sheepy, the reason why it doesn't work is that java.util.logging.Logger has a root logger that defaults to Level.INFO, and the ConsoleHandler attached to that root logger also defaults to Level.INFO. Therefore, in order to see the FINE (, FINER or FINEST) output, you need to set the default value of the root logger and its ConsoleHandler to Level.FINE as follows:


The problem of your Update (solution)

As mentioned by @mins, you will have the messages printed twice on the console for INFO and above: first by the anonymous logger, then by its parent, the root logger which also has a ConsoleHandler set to INFO by default. To disable the root logger, you need to add this line of code: logger.setUseParentHandlers(false);

There are other ways to prevent logs from being processed by default Console handler of the root logger mentioned by @Sheepy, e.g.:

Logger.getLogger("").getHandlers()[0].setLevel( Level.OFF );

But Logger.getLogger("").setLevel( Level.OFF ); won't work because it only blocks the message passed directly to the root logger, not the message comes from a child logger. To illustrate how the Logger Hierarchy works, I draw the following diagram:

enter image description here

public void setLevel(Level newLevel) set the log level specifying which message levels will be logged by this logger. Message levels lower than this value will be discarded. The level value Level.OFF can be used to turn off logging. If the new level is null, it means that this node should inherit its level from its nearest ancestor with a specific (non-null) level value.

Running Python code in Vim

I have this on my .vimrc:

"map <F9> :w<CR>:!python %<CR>"

which saves the current buffer and execute the code with presing only Esc + F9

windows batch file rename

@echo off
pushd "pathToYourFolder" || exit /b
for /f "eol=: delims=" %%F in ('dir /b /a-d *_*.jpg') do (
  for /f "tokens=1* eol=_ delims=_" %%A in ("%%~nF") do ren "%%F" "%%~nB_%%A%%~xF"

Note: The name is split at the first occurrence of _. If a file is named "part1_part2_part3.jpg", then it will be renamed to "part2_part3_part1.jpg"

Checking if an object is a given type in Swift

I have 2 ways of doing it:

if let thisShape = aShape as? Square 



Here is a detailed example:

class Shape { }
class Square: Shape { } 
class Circle: Shape { }

var aShape = Shape()
aShape = Square()

if let thisShape = aShape as? Square {
    println("Its a square")
} else {
    println("Its not a square")

if aShape.isKindOfClass(Square) {
    println("Its a square")
} else {
    println("Its not a square")

Edit: 3 now:

let myShape = Shape()
if myShape is Shape {
    print("yes it is")

How to get an input text value in JavaScript

<script type="text/javascript">
function kk(){
    var lol = document.getElementById('lolz').value;


<body onload="onload();">
    <input type="text" name="enter" class="enter" id="lolz" value=""/>
    <input type="button" value="click" onclick="kk();"/>

use this

How to use a Java8 lambda to sort a stream in reverse order?

You can adapt the solution you linked in How to sort ArrayList<Long> in Java in decreasing order? by wrapping it in a lambda:

.sorted((f1, f2) ->, f1.lastModified())

note that f2 is the first argument of, not the second, so the result will be reversed.

How to override the [] operator in Python?

You need to use the __getitem__ method.

class MyClass:
    def __getitem__(self, key):
        return key * 2

myobj = MyClass()
myobj[3] #Output: 6

And if you're going to be setting values you'll need to implement the __setitem__ method too, otherwise this will happen:

>>> myobj[5] = 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: MyClass instance has no attribute '__setitem__'

C#: Dynamic runtime cast

Try a generic:

public static T CastTo<T>(this dynamic obj, bool safeCast) where T:class
      return (T)obj;
      if(safeCast) return null;
      else throw;

This is in extension method format, so its usage would be as if it were a member of dynamic objects:

dynamic myDynamic = new Something();
var typedObject = myDynamic.CastTo<Something>(false);

EDIT: Grr, didn't see that. Yes, you could reflectively close the generic, and it wouldn't be hard to hide in a non-generic extension method:

public static dynamic DynamicCastTo(this dynamic obj, Type castTo, bool safeCast)
   MethodInfo castMethod = this.GetType().GetMethod("CastTo").MakeGenericMethod(castTo);
   return castMethod.Invoke(null, new object[] { obj, safeCast });

I'm just not sure what you'd get out of this. Basically you're taking a dynamic, forcing a cast to a reflected type, then stuffing it back in a dynamic. Maybe you're right, I shouldn't ask. But, this'll probably do what you want. Basically when you go into dynamic-land, you lose the need to perform most casting operations as you can discover what an object is and does through reflective methods or trial and error, so there aren't many elegant ways to do this.

Find Oracle JDBC driver in Maven repository

You can find a Github simple sample project for use a Oracle JDBC Driver on Maven Project here.

You can find all explication for your continous integration + a sample and run on Travis-CI.


SELECT INTO Variable in MySQL DECLARE causes syntax error?

You can also use SET instead of DECLARE

SET @myvar := (SELECT somevalue INTO myvar FROM mytable WHERE uid=1);

SELECT myvar;

How to disable phone number linking in Mobile Safari?

I had an ABN (Australian Business Number) that iPad Safari insisted on turning into a phone number link. None of the suggestions helped. My solution was to put img tags between the numbers.

ABN 98<img class="PreventSafariFromTurningIntoLink" /> 009<img /> 675<img /> 709

The class exists only to document what the img tags are for.

Works on iPad 1 (4.3.1) and iPad 2 (4.3.3).

How to export data as CSV format from SQL Server using sqlcmd?

You can do it in a hackish way. Careful using the sqlcmd hack. If the data has double quotes or commas you will run into trouble.

You can use a simple script to do it properly:

' Data Exporter                                                 '
'                                                               '
' Description: Allows the output of data to CSV file from a SQL '
'       statement to either Oracle, SQL Server, or MySQL        '
' Author: C. Peter Chen,                   '
' Version Tracker:                                              '
'       1.0   20080414 Original version                         '
'   1.1   20080807 Added email functionality                '
option explicit
dim dbType, dbHost, dbName, dbUser, dbPass, outputFile, email, subj, body, smtp, smtpPort, sqlstr

' Configuration '
dbType = "oracle"                 ' Valid values: "oracle", "sqlserver", "mysql"
dbHost = "dbhost"                 ' Hostname of the database server
dbName = "dbname"                 ' Name of the database/SID
dbUser = "username"               ' Name of the user
dbPass = "password"               ' Password of the above-named user
outputFile = "c:\output.csv"      ' Path and file name of the output CSV file
email = "[email protected]"           ' Enter email here should you wish to email the CSV file (as attachment); if no email, leave it as empty string ""
  subj = "Email Subject"          ' The subject of your email; required only if you send the CSV over email
  body = "Put a message here!"    ' The body of your email; required only if you send the CSV over email
  smtp = ""        ' Name of your SMTP server; required only if you send the CSV over email
  smtpPort = 25                   ' SMTP port used by your server, usually 25; required only if you send the CSV over email
sqlStr = "select user from dual"  ' SQL statement you wish to execute
' End Configuration '

dim fso, conn

'Create filesystem object 
set fso = CreateObject("Scripting.FileSystemObject")

'Database connection info
set Conn = CreateObject("ADODB.connection")
Conn.ConnectionTimeout = 30
Conn.CommandTimeout = 30
if dbType = "oracle" then"Provider=MSDAORA.1;User ID=" & dbUser & ";Password=" & dbPass & ";Data Source=" & dbName & ";Persist Security Info=False")
elseif dbType = "sqlserver" then"Driver={SQL Server};Server=" & dbHost & ";Database=" & dbName & ";Uid=" & dbUser & ";Pwd=" & dbPass & ";")
elseif dbType = "mysql" then"DRIVER={MySQL ODBC 3.51 Driver}; SERVER=" & dbHost & ";PORT=3306;DATABASE=" & dbName & "; UID=" & dbUser & "; PASSWORD=" & dbPass & "; OPTION=3")
end if

' Subprocedure to generate data.  Two parameters:
'   1. fPath=where to create the file
'   2. sqlstr=the database query
sub MakeDataFile(fPath, sqlstr)
    dim a, showList, intcount
    set a = fso.createtextfile(fPath)

    set showList = conn.execute(sqlstr)
    for intcount = 0 to showList.fields.count -1
        if intcount <> showList.fields.count-1 then
            a.write """" & showList.fields(intcount).name & ""","
            a.write """" & showList.fields(intcount).name & """"
        end if
    a.writeline ""

    do while not showList.eof
        for intcount = 0 to showList.fields.count - 1
            if intcount <> showList.fields.count - 1 then
                a.write """" & showList.fields(intcount).value & ""","
                a.write """" & showList.fields(intcount).value & """"
            end if
        a.writeline ""
    set showList = nothing

    set a = nothing
end sub

' Call the subprocedure
call MakeDataFile(outputFile,sqlstr)

' Close
set fso = nothing
set conn = nothing

if email <> "" then
    dim objMessage
    Set objMessage = CreateObject("CDO.Message")
    objMessage.Subject = "Test Email from vbs"
    objMessage.From = email
    objMessage.To = email
    objMessage.TextBody = "Please see attached file."
    objMessage.AddAttachment outputFile

    objMessage.Configuration.Fields.Item ("") = 2
    objMessage.Configuration.Fields.Item ("") = smtp
    objMessage.Configuration.Fields.Item ("") = smtpPort


end if

'You're all done!!  Enjoy the file created.
msgbox("Data Writer Done!")

Source: Writing SQL output to CSV with VBScript.

Delete all files of specific type (extension) recursively down a directory using a batch file

If you are trying to delete certain .extensions in the C: drive use this cmd:

del /s c:\*.blaawbg

I had a customer that got a encryption virus and i needed to find all junk files and delete them.

Google Chrome display JSON AJAX response as tree and not as a plain text

The correct content-type for JSON data is application/json. I assume that is what you are missing.

What is a Data Transfer Object (DTO)?

The principle behind Data Transfer Object is to create new Data Objects that only include the necessary properties you need for a specific data transaction.

Benefits include:

Make data transfer more secure Reduce transfer size if you remove all unnecessary data.

Read More:

Select folder dialog WPF

Microsoft.Win32.OpenFileDialog is the standard dialog that any application on Windows uses. Your user won't be surprised by its appearance when you use WPF in .NET 4.0

The dialog was altered in Vista. WPF in .NET 3.0 and 3.5 still used the legacy dialog but that was fixed in .NET 4.0. I can only guess that you started this thread because you are seeing that old dialog. Which probably means you're actually running a program that is targeting 3.5. Yes, the Winforms wrapper did get the upgrade and shows the Vista version. System.Windows.Forms.OpenFileDialog class, you'll need to add a reference to System.Windows.Forms.

How to remove decimal part from a number in C#

here is a trick

a =  double.Parse(a.ToString().Split(',')[0])

org.springframework.web.client.HttpClientErrorException: 400 Bad Request

This is what worked for me. Issue is earlier I didn't set Content Type(header) when I used exchange method.

MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();
map.add("param1", "123");
map.add("param2", "456");
map.add("param3", "789");
map.add("param4", "123");
map.add("param5", "456");

HttpHeaders headers = new HttpHeaders();

final HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<MultiValueMap<String, String>>(map ,
JSONObject jsonObject = null;

try {
    RestTemplate restTemplate = new RestTemplate();
    ResponseEntity<String> responseEntity =
            "https://url", HttpMethod.POST, entity,

    if (responseEntity.getStatusCode() == HttpStatus.CREATED) {
        try {
            jsonObject = new JSONObject(responseEntity.getBody());
        } catch (JSONException e) {
            throw new RuntimeException("JSONException occurred");
  } catch (final HttpClientErrorException httpClientErrorException) {
        throw new ExternalCallBadRequestException();
  } catch (HttpServerErrorException httpServerErrorException) {
        throw new ExternalCallServerErrorException(httpServerErrorException);
  } catch (Exception exception) {
        throw new ExternalCallServerErrorException(exception);

ExternalCallBadRequestException and ExternalCallServerErrorException are the custom exceptions here.

Note: Remember HttpClientErrorException is thrown when a 4xx error is received. So if the request you send is wrong either setting header or sending wrong data, you could receive this exception.

Difference between `Optional.orElse()` and `Optional.orElseGet()`

Considering the following code:

import java.util.Optional;

// one class needs to have a main() method
public class Test
  public String orelesMethod() {
    System.out.println("in the Method");
    return "hello";

  public void test() {
    String value;
    value = Optional.<String>ofNullable("test").orElseGet(this::orelesMethod);

    value = Optional.<String>ofNullable("test").orElse(orelesMethod());

  // arguments are passed using the text field below this editor
  public static void main(String[] args)
    Test test = new Test();


if we get value in this way: Optional.<String>ofNullable(null), there is no difference between orElseGet() and orElse(), but if we get value in this way: Optional.<String>ofNullable("test"), orelesMethod() in orElseGet() will not be called but in orElse() it will be called

Is it possible to put CSS @media rules inline?


No, Media Queries cannot be used in this way

<span style="@media (...) { ... }"></span>


But if you want provided a specific behavior usable on the fly AND responsive, you can use the style markup and not the attribute.


<style scoped>
.on-the-fly-behavior {
    background-image: url('particular_ad.png'); 
@media (max-width: 300px) {
    .on-the-fly-behavior {
        background-image: url('particular_ad_small.png');
<span class="on-the-fly-behavior"></span>

See the code working in live on CodePen

In my Blog for example, I inject a <style> markup in <head> just after <link> declaration for CSS and it's contain the content of a textarea provided beside of real content textarea for create extra-class on the fly when I wrote an artitle.

Note : the scoped attribute is a part of HTML5 specification. If you do not use it, the validator will blame you but browsers currently not support the real purpose : scoped the content of <style> only on immediatly parent element and that element's child elements. Scoped is not mandatory if the <style> element is in <head> markup.

UPDATE: I advice to always use rules in the mobile first way so previous code should be:

<style scoped>
/* 0 to 299 */
.on-the-fly-behavior {
    background-image: url('particular_ad_small.png'); 
/* 300 to X */
@media (min-width: 300px) { /* or 301 if you want really the same as previously.  */
    .on-the-fly-behavior {   
        background-image: url('particular_ad.png');
<span class="on-the-fly-behavior"></span>

Saving a high resolution image in R

You can do the following. Add your ggplot code after the first line of code and end with

tiff("test.tiff", units="in", width=5, height=5, res=300)
# insert ggplot code

res=300 specifies that you need a figure with a resolution of 300 dpi. The figure file named 'test.tiff' is saved in your working directory.

Change width and height in the code above depending on the desired output.

Note that this also works for other R plots including plot, image, and pheatmap.

Other file formats

In addition to TIFF, you can easily use other image file formats including JPEG, BMP, and PNG. Some of these formats require less memory for saving.

Re-sign IPA (iPhone)

The answers to this question are a little out of date and missing potentially key steps, so this is an updated guide for installing an app from an external developer.

----- How to Resign an iOS App -----

Let's say you receive an app (e.g. MyApp.ipa) from another developer, and you want to be able to install and run it on your devices (by using ideviceinstaller, for example).

Prepare New Signing Assets

The first step is to attain a Provisioning Profile which includes all of the devices you wish to install and run on. Ensure that the profile contains a certificate that you have installed in your Keychain Access (e.g. iPhone Developer: Some Body (XXXXXXXXXX) ). Download the profile (MyProfile.mobileprovision) so you can replace the profile embedded in the app.

Next, we are going to prepare an entitlements file to include in the signing. Open up your terminal and run the following.

$ security cms -D -i path/to/MyProfile.mobileprovision > provision.plist

This will create an xml file describing your Provisioning Profile. Next, we want to extract the entitlements into a file.

$ /usr/libexec/PlistBuddy -x -c 'Print :Entitlements' provision.plist > entitlements.plist

Replace The Provisioning Profile and Resign App

If you are working with a .ipa file, first, unzip the app (if you have a .app instead, you can skip this step).

$ unzip MyApp.ipa

Your working directory will now contain Payload/ and Payload/ Next, remove the old code signature files.

$ rm -rf Payload/

Replace the existing provisioning profile (i.e. embedded.mobileprovision) with your own.

$ cp path/to/MyProfile.mobileprovision Payload/

Now sign the app with the certificate included in your provisioning profile and the entitlements.plist that you created earlier.

$ /usr/bin/codesign -f -s "iPhone Developer: Some Body (XXXXXXXXXX)" --entitlements entitlements.plist Payload/

IMPORTANT: You must also resign all frameworks included in the app. You will find these in Payload/ If the app is written in Swift or if it includes any additional frameworks these must be resigned or the app will install but not run.

$ /usr/bin/codesign -f -s "iPhone Developer: Some Body (XXXXXXXXXX)" --entitlements entitlements.plist Payload/*

You can now rezip the app.

$ zip -qr MyApp-resigned.ipa Payload


You may now remove the Payload directory since you have your original app (MyApp.ipa) and your resigned version (MyApp-resigned.ipa). You can now install MyApp-resigned.ipa on any device included in your provisioning profile.

Creating a BAT file for python script


Is there a way to use shell_exec without waiting for the command to complete?

That will work but you will have to be careful not to overload your server because it will create a new process every time you call this function which will run in background. If only one concurrent call at the same time then this workaround will do the job.

If not then I would advice to run a message queue like for instance beanstalkd/gearman/amazon sqs.

what is the use of annotations @Id and @GeneratedValue(strategy = GenerationType.IDENTITY)? Why the generationtype is identity?

In a Object Relational Mapping context, every object needs to have a unique identifier. You use the @Id annotation to specify the primary key of an entity.

The @GeneratedValue annotation is used to specify how the primary key should be generated. In your example you are using an Identity strategy which

Indicates that the persistence provider must assign primary keys for the entity using a database identity column.

There are other strategies, you can see more here.

SQL update fields of one table from fields of another one

you can build and execute dynamic sql to do this, but its really not ideal

java- reset list iterator to first element of the list

You can call listIterator method again to get an instance of iterator pointing at beginning of list:

iter = list.listIterator();

How to close a window using jQuery

This will only work for windows which are opened by using; method. Try this


How can I add private key to the distribution certificate?

For Developer certificate, you need to create a developer .mobileprovision profile and install add it to your XCode. In case you want to distribute the app using an adhoc distribution profile you will require AdHoc Distribution certificate and private key installed in your keychain.

If you have not created the cert, here are steps to create it. Incase it has already been created by someone in your team, ask him to share the cert and private key. If that someone is no longer in your team then you can revoke the cert from developer account and create new.

mysqld_safe Directory '/var/run/mysqld' for UNIX socket file don't exists

See this bug:

There seems to be a temporary fix there

Create a newfile /etc/tmpfiles.d/mysql.conf:

# systemd tmpfile settings for mysql
# See tmpfiles.d(5) for details

d /var/run/mysqld 0755 mysql mysql -

After reboot, mysql should start normally.

Difference between <span> and <div> with text-align:center;?

Like other have said, span is an in-line element.

See here:

Additionally, you can make a span behave like a div by applying a

style="display: block; margin: 0px auto; text-align: center;"

Angular 2 - Using 'this' inside setTimeout

You need to use Arrow function ()=> ES6 feature to preserve this context within setTimeout.

// var that = this;                             // no need of this line
this.messageSuccess = true;

setTimeout(()=>{                           //<<<---using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

SFTP in Python? (platform independent)

There are a bunch of answers that mention pysftp, so in the event that you want a context manager wrapper around pysftp, here is a solution that is even less code that ends up looking like the following when used

path = "sftp://user:p@[email protected]/path/to/file.txt"

# Read a file
with open_sftp(path) as f:
    s = 
print s

# Write to a file
with open_sftp(path, mode='w') as f:
    f.write("Some content.") 

The (fuller) example:

This context manager happens to have auto-retry logic baked in in the event you can't connect the first time around (which surprisingly happens more often than you'd expect in a production environment...)

The context manager gist for open_sftp:

How can I assign an ID to a view programmatically?

Android id overview

An Android id is an integer commonly used to identify views; this id can be assigned via XML (when possible) and via code (programmatically.) The id is most useful for getting references for XML-defined Views generated by an Inflater (such as by using setContentView.)

Assign id via XML

  • Add an attribute of android:id="@+id/somename" to your view.
  • When your application is built, the android:id will be assigned a unique int for use in code.
  • Reference your android:id's int value in code using "" (effectively a constant.)
  • this int can change from build to build so never copy an id from gen/, just use "".
  • (Also, an id assigned to a Preference in XML is not used when the Preference generates its View.)

Assign id via code (programmatically)

  • Manually set ids using someView.setId(int);
  • The int must be positive, but is otherwise arbitrary- it can be whatever you want (keep reading if this is frightful.)
  • For example, if creating and numbering several views representing items, you could use their item number.

Uniqueness of ids

  • XML-assigned ids will be unique.
  • Code-assigned ids do not have to be unique
  • Code-assigned ids can (theoretically) conflict with XML-assigned ids.
  • These conflicting ids won't matter if queried correctly (keep reading).

When (and why) conflicting ids don't matter

  • findViewById(int) will iterate depth-first recursively through the view hierarchy from the View you specify and return the first View it finds with a matching id.
  • As long as there are no code-assigned ids assigned before an XML-defined id in the hierarchy, findViewById( will always return the XML-defined View so id'd.

Dynamically Creating Views and Assigning IDs

  • In layout XML, define an empty ViewGroup with id.
  • Such as a LinearLayout with android:id="@+id/placeholder".
  • Use code to populate the placeholder ViewGroup with Views.
  • If you need or want, assign any ids that are convenient to each view.
  • Query these child views using placeholder.findViewById(convenientInt);

  • API 17 introduced View.generateViewId() which allows you to generate a unique ID.

If you choose to keep references to your views around, be sure to instantiate them with getApplicationContext() and be sure to set each reference to null in onDestroy. Apparently leaking the Activity (hanging onto it after is is destroyed) is wasteful.. :)

Reserve an XML android:id for use in code

API 17 introduced View.generateViewId() which generates a unique ID. (Thanks to take-chances-make-changes for pointing this out.)*

If your ViewGroup cannot be defined via XML (or you don't want it to be) you can reserve the id via XML to ensure it remains unique:

Here, values/ids.xml defines a custom id:

<?xml version="1.0" encoding="utf-8"?>
    <item name="reservedNamedId" type="id"/>

Then once the ViewGroup or View has been created, you can attach the custom id


Conflicting id example

For clarity by way of obfuscating example, lets examine what happens when there is an id conflict behind the scenes.


<?xml version="1.0" encoding="utf-8"?>
    android:orientation="vertical" >
        android:orientation="horizontal" >

To simulate a conflict, lets say our latest build assigned an int value of 12..

Next, defines some adds views programmatically (via code):

int placeholderId =; // placeholderId==12
// returns *placeholder* which has id==12:
ViewGroup placeholder = (ViewGroup)this.findViewById(placeholderId);
for (int i=0; i<20; i++){
    TextView tv = new TextView(this.getApplicationContext());
    // One new TextView will also be assigned an id==12:

So placeholder and one of our new TextViews both have an id of 12! But this isn't really a problem if we query placeholder's child views:

// Will return a generated TextView:

// Whereas this will return the ViewGroup *placeholder*;
// as long as its remains 12: 

*Not so bad

Merge data frames based on rownames in R

See ?merge:

the name "row.names" or the number 0 specifies the row names.


R> de <- merge(d, e, by=0, all=TRUE)  # merge by row names (by=0 or by="row.names")
R> de[] <- 0                 # replace NA values
R> de
  Row.names   a   b   c   d   e   f   g   h   i  j  k  l  m  n  o  p  q  r  s
1         1 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10 11 12 13 14 15 16 17 18 19
2         2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9  1  0  0  0  0  0  0  0  0  0
3         3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0  0 21 22 23 24 25 26 27 28 29
1 20
2  0
3 30

React.js inline style best practices

There aren't a lot of "Best Practices" yet. Those of us that are using inline-styles, for React components, are still very much experimenting.

There are a number of approaches that vary wildly: React inline-style lib comparison chart

All or nothing?

What we refer to as "style" actually includes quite a few concepts:

  • Layout — how an element/component looks in relationship to others
  • Appearance — the characteristics of an element/component
  • Behavior and state — how an element/component looks in a given state

Start with state-styles

React is already managing the state of your components, this makes styles of state and behavior a natural fit for colocation with your component logic.

Instead of building components to render with conditional state-classes, consider adding state-styles directly:

// Typical component with state-classes
 className={classnames({ 'todo-list__item': true, 'is-complete': item.complete })} />

// Using inline-styles for state
<li className='todo-list__item'
 style={(item.complete) ? styles.complete : {}} />

Note that we're using a class to style appearance but no longer using any .is- prefixed class for state and behavior.

We can use Object.assign (ES6) or _.extend (underscore/lodash) to add support for multiple states:

// Supporting multiple-states with inline-styles
<li 'todo-list__item'
 style={Object.assign({}, item.complete && styles.complete, item.due && styles.due )}>

Customization and reusability

Now that we're using Object.assign it becomes very simple to make our component reusable with different styles. If we want to override the default styles, we can do so at the call-site with props, like so: <TodoItem dueStyle={ fontWeight: "bold" } />. Implemented like this:

<li 'todo-list__item'
         item.due && styles.due,
         item.due && this.props.dueStyles)}>


Personally, I don't see compelling reason to inline layout styles. There are a number of great CSS layout systems out there. I'd just use one.

That said, don't add layout styles directly to your component. Wrap your components with layout components. Here's an example.

// This couples your component to the layout system
// It reduces the reusability of your component
 className="col-xs-12 col-sm-6 col-md-8"
 lastName="Chan" />

// This is much easier to maintain and change
<div class="col-xs-12 col-sm-6 col-md-8">
   lastName="Chan" />

For layout support, I often try to design components to be 100% width and height.


This is the most contentious area of the "inline-style" debate. Ultimately, it's up to the component your designing and the comfort of your team with JavaScript.

One thing is certain, you'll need the assistance of a library. Browser-states (:hover, :focus), and media-queries are painful in raw React.

I like Radium because the syntax for those hard parts is designed to model that of SASS.

Code organization

Often you'll see a style object outside of the module. For a todo-list component, it might look something like this:

var styles = {
  root: {
    display: "block"
  item: {
    color: "black"

    complete: {
      textDecoration: "line-through"

    due: {
      color: "red"

getter functions

Adding a bunch of style logic to your template can get a little messy (as seen above). I like to create getter functions to compute styles:

  getStyles: function () {
    return Object.assign(
      item.props.complete && styles.complete,
      item.props.due && styles.due,
      item.props.due && this.props.dueStyles

  render: function () {
    return <li style={this.getStyles()}>{this.props.item}</li>

Further watching

I discussed all of these in more detail at React Europe earlier this year: Inline Styles and when it's best to 'just use CSS'.

I'm happy to help as you make new discoveries along the way :) Hit me up -> @chantastic

When to use window.opener / window.parent /

  • window.opener refers to the window that called ... ) to open the window from which it's called
  • window.parent refers to the parent of a window in a <frame> or <iframe>
  • refers to the top-most window from a window nested in one or more layers of <iframe> sub-windows

Those will be null (or maybe undefined) when they're not relevant to the referring window's situation. ("Referring window" means the window in whose context the JavaScript code is run.)

Bind TextBox on Enter-key press

A different solution (not using xaml but still quite clean I think).

class ReturnKeyTextBox : TextBox
    protected override void OnKeyUp(KeyEventArgs e)
        if (e.Key == Key.Return)

How to fill a datatable with List<T>

I also had to come up with an alternate solution, as none of the options listed here worked in my case. I was using an IEnumerable and the underlying data was a IEnumerable and the properties couldn't be enumerated. This did the trick:

// remove "this" if not on C# 3.0 / .NET 3.5
public static DataTable ConvertToDataTable<T>(this IEnumerable<T> data)
    List<IDataRecord> list = data.Cast<IDataRecord>().ToList();

    PropertyDescriptorCollection props = null;
    DataTable table = new DataTable();
    if (list != null && list.Count > 0)
        props = TypeDescriptor.GetProperties(list[0]);
        for (int i = 0; i < props.Count; i++)
            PropertyDescriptor prop = props[i];
            table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
    if (props != null)
        object[] values = new object[props.Count];
        foreach (T item in data)
            for (int i = 0; i < values.Length; i++)
                values[i] = props[i].GetValue(item) ?? DBNull.Value;
    return table;

Is there possibility of sum of ArrayList without looping

Given that a list can hold any type of object, there is no built in method which allows you to sum all the elements. You could do something like this:

int sum = 0;

for( Integer i : ( ArrayList<Integer> )tt ) {
  sum += i;

Alternatively you could create your own container type which inherits from ArrayList but also implements a method called sum() which implements the code above.

Determine if an element has a CSS class with jQuery

from the FAQ

elem = $("#elemid");
if ( (".class")) {
   // whatever


elem = $("#elemid");
if (elem.hasClass ("class")) {
   // whatever

ResultSet exception - before start of result set

You have to call next() before you can start reading values from the first row. beforeFirst puts the cursor before the first row, so there's no data to read.

Permission denied for relation

You should:

  1. connect to the database by means of the DBeaver with postgres user
  2. on the left tab open your database
  3. open Roles tab/dropdown
  4. select your user
  5. on the right tab press 'Permissions tab'
  6. press your schema tab
  7. press tables tab/dropdown
  8. select all tables
  9. select all required permissions checkboxes (or press Grant All)
  10. press Save

CSS text-align: center; is not centering things

To make a inline-block element align center horizontally in its parent, add text-align:center to its parent.

How to read the value of a private field from a different class in Java?

You can use jOOR for that.

class Foo {
    private final String value = "ABC";
class Bar {
    private final Foo foo = new Foo();
    public String value() {
        return org.joor.Reflect
class BarTest {
    void accessPrivateField() {
        Assertions.assertEquals(new Bar().value(), "ABC");

How to pass arguments from command line to gradle

I have written a piece of code that puts the command line arguments in the format that gradle expects.

// this method creates a command line arguments
def setCommandLineArguments(commandLineArgs) {
    // remove spaces 
    def arguments = commandLineArgs.tokenize()

            // create a string that can be used by Eval 
            def cla = "["
            // go through the list to get each argument
            arguments.each {
                    cla += "'" + "${it}" + "',"

    // remove last "," add "]" and set the args 
    return cla.substring(0, cla.lastIndexOf(',')) + "]"

my task looks like this:

task runProgram(type: JavaExec) {
    if ( project.hasProperty("commandLineArgs") ) {
            args setCommandLineArguments(commandLineArgs) )

To pass the arguments from the command line you run this:

gradle runProgram -PcommandLineArgs="arg1 arg2 arg3 arg4"    

Convert String to Uri

You can parse a String to a Uri by using Uri.parse() as shown below:

Uri myUri = Uri.parse("");

The following is an example of how you can use your newly created Uri in an implicit intent. To be viewed in a browser on the users phone.

// Creates a new Implicit Intent, passing in our Uri as the second paramater.
Intent webIntent = new Intent(Intent.ACTION_VIEW, myUri);

// Checks to see if there is an Activity capable of handling the intent
if (webIntent.resolveActivity(getPackageManager()) != null){

NB: There is a difference between Androids URI and Uri.

Convert a JSON Object to Buffer and Buffer to JSON Object back

You need to stringify the json, not calling toString

var buf = Buffer.from(JSON.stringify(obj));

And for converting string to json obj :

var temp = JSON.parse(buf.toString());

What is the difference between i++ and ++i?

The way the operator works is that it gets incremented at the same time, but if it is before a variable, the expression will evaluate with the incremented/decremented variable:

int x = 0;   //x is 0
int y = ++x; //x is 1 and y is 1

If it is after the variable the current statement will get executed with the original variable, as if it had not yet been incremented/decremented:

int x = 0;   //x is 0
int y = x++; //'y = x' is evaluated with x=0, but x is still incremented. So, x is 1, but y is 0

I agree with dcp in using pre-increment/decrement (++x) unless necessary. Really the only time I use the post-increment/decrement is in while loops or loops of that sort. These loops are the same:

while (x < 5)  //evaluates conditional statement
    //some code
    ++x;       //increments x


while (x++ < 5) //evaluates conditional statement with x value before increment, and x is incremented
    //some code

You can also do this while indexing arrays and such:

int i = 0;
int[] MyArray = new int[2];
MyArray[i++] = 1234; //sets array at index 0 to '1234' and i is incremented
MyArray[i] = 5678;   //sets array at index 1 to '5678'
int temp = MyArray[--i]; //temp is 1234 (becasue of pre-decrement);

Etc, etc...

Convert Time DataType into AM PM Format:

Here are the various ways you may pull this (depending on your needs).

Using the Time DataType:

DECLARE @Time Time = '15:04:46.217'
SELECT --'3:04PM'
       CONVERT(VarChar(7), @Time, 0),

       --' 3:04PM' --Leading Space.
       RIGHT(' ' + CONVERT(VarChar(7), @Time, 0), 7),

       --' 3:04 PM' --Space before AM/PM.
       STUFF(RIGHT(' ' + CONVERT(VarChar(7), @Time, 0), 7), 6, 0, ' '),

       --'03:04 PM' --Leading Zero.  This answers the question above.
       STUFF(RIGHT('0' + CONVERT(VarChar(7), @Time, 0), 7), 6, 0, ' ')

       --'03:04 PM' --This only works in SQL Server 2012 and above.  :)
       ,FORMAT(CAST(@Time as DateTime), 'hh:mm tt')--Comment out for SS08 or less.

Using the DateTime DataType:

DECLARE @Date DateTime = '2016-03-17 15:04:46.217'
SELECT --' 3:04PM' --No space before AM/PM.
       RIGHT(CONVERT(VarChar(19), @Date, 0), 7),

       --' 3:04 PM' --Space before AM/PM.
       STUFF(RIGHT(CONVERT(VarChar(19), @Date, 0), 7), 6, 0, ' '),

       --'3:04 PM' --No Leading Space.
       LTRIM(STUFF(RIGHT(CONVERT(VarChar(19), @Date, 0), 7), 6, 0, ' ')),

       --'03:04 PM' --Leading Zero.
       STUFF(REPLACE(RIGHT(CONVERT(VarChar(19), @Date, 0), 7), ' ', '0'), 6, 0, ' ')

       --'03:04 PM' --This only works in SQL Server 2012 and above.  :)
       ,FORMAT(@Date, 'hh:mm tt')--Comment line out for SS08 or less.

Reference requirements.txt for the install_requires kwarg in setuptools file

Another possible solution...

def gather_requirements(top_path=None):
    """Captures requirements from repo.

    Expected file format is: requirements[-_]<optional-extras>.txt

    For example:

        pip install -e .[foo]

    Would require:




    from import PipSession
    from pip.req import parse_requirements
    import re

    session = PipSession()
    top_path = top_path or os.path.realpath(os.getcwd())
    extras = {}
    for filepath in tree(top_path):
        filename = os.path.basename(filepath)
        basename, ext = os.path.splitext(filename)
        if ext == '.txt' and basename.startswith('requirements'):
            if filename == 'requirements.txt':
                extra_name = 'requirements'
                _, extra_name = re.split(r'[-_]', basename, 1)
            if extra_name:
                reqs = [str(ir.req) for ir in parse_requirements(filepath, session=session)]
                extras.setdefault(extra_name, []).extend(reqs)
    all_reqs = set()
    for key, values in extras.items():
    extras['all'] = list(all_reqs)
    return extras

and then to use...

reqs = gather_requirements()
install_reqs = reqs.pop('requirements', [])
test_reqs = reqs.pop('test', [])
    'install_requires': install_reqs,
    'test_requires': test_reqs,
    'extras_require': reqs,

"This project is incompatible with the current version of Visual Studio"

In my case it was an incompatible Project Type. Editing project file and removing ProjectTypeGuids node resolved the issue of loading the project (I had already re-targeted the framework version as advised here).

Probably the project type is not supported in the (most likely) NEW version of VS, so you will have to adjust (update) the code to work properly (if possible), but at least you can see the content through VS.

Using Composer's Autoload

There also other ways to use the composer autoload features. Ways that can be useful to load packages without namespaces or packages that come with a custom autoload function.

For example if you want to include a single file that contains an autoload function as well you can use the "files" directive as follows:

"autoload": {
    "psr-0": {
        "": "src/",
        "SymfonyStandard": "app/"
    "files": ["vendor/wordnik/wordnik-php/wordnik/Swagger.php"]

And inside the Swagger.php file we got:

function swagger_autoloader($className) {
    $currentDir = dirname(__FILE__);
    if (file_exists($currentDir . '/' . $className . '.php')) {
        include $currentDir . '/' . $className . '.php';
    } elseif (file_exists($currentDir . '/models/' . $className . '.php')) {
        include $currentDir . '/models/' . $className . '.php';

Otherwise you may want to use a classmap reference:

    "autoload": {
        "classmap": ["src/", "lib/", "Something.php"]

Note: during your tests remember to launch the composer dump-autoload command or you won't see any change!

./composer.phar dump-autoload

Happy autoloading =)

Create Local SQL Server database

After installation you need to connect to Server Name : localhost to start using the local instance of SQL Server.

Once you are connected to the local instance, right click on Databases and create a new database.

How to hide keyboard in swift on pressing return key?

  • Add UITextFieldDelegate to the class declaration:

    class ViewController: UIViewController, UITextFieldDelegate
  • Connect the textfield or write it programmatically

    @IBOutlet weak var userText: UITextField!
  • set your view controller as the text fields delegate in view did load:

    override func viewDidLoad() {
    self.userText.delegate = self
  • Add the following function

    func textFieldShouldReturn(userText: UITextField!) -> Bool {
        return true;

    with all this your keyboard will begin to dismiss by touching outside the textfield aswell as by pressing return key.

Bootstrap: Open Another Modal in Modal

data-dismiss makes the current modal window force close

data-toggle opens up a new modal with the href content inside it

<a data-dismiss="modal" data-toggle="modal" href="#lost">Click</a>


<a data-dismiss="modal" onclick="call the new div here">Click</a>

do let us know if it works.

How to use lifecycle method getDerivedStateFromProps as opposed to componentWillReceiveProps

As mentioned by Dan Abramov

Do it right inside render

We actually use that approach with memoise one for any kind of proxying props to state calculations.

Our code looks this way

// ./decorators/memoized.js  
import memoizeOne from 'memoize-one';

export function memoized(target, key, descriptor) {
  descriptor.value = memoizeOne(descriptor.value);
  return descriptor;

// ./components/exampleComponent.js
import React from 'react';
import { memoized } from 'src/decorators';

class ExampleComponent extends React.Component {
  buildValuesFromProps() {
    const {
    } = this.props
    return {
      value1: buildValue1(watchedProp1, watchedProp2),
      value2: buildValue2(watchedProp1, watchedProp3, watchedProp5),
      value3: buildValue3(watchedProp3, watchedProp4, watchedProp5),

  buildValue1(watchedProp1, watchedProp2) {
    return ...;

  buildValue2(watchedProp1, watchedProp3, watchedProp5) {
    return ...;

  buildValue3(watchedProp3, watchedProp4, watchedProp5) {
    return ...;

  render() {
    const {
    } = this.buildValuesFromProps();

    return (
        <Component1 value={value1}>
        <Component2 value={value2}>
        <Component3 value={value3}>

The benefits of it are that you don't need to code tons of comparison boilerplate inside getDerivedStateFromProps or componentWillReceiveProps and you can skip copy-paste initialization inside a constructor.


This approach is used only for proxying the props to state, in case you have some inner state logic it still needs to be handled in component lifecycles.

Are strongly-typed functions as parameters possible in TypeScript?

I realize this post is old, but there's a more compact approach that is slightly different than what was asked, but may be a very helpful alternative. You can essentially declare the function in-line when calling the method (Foo's save() in this case). It would look something like this:

class Foo {
    save(callback: (n: number) => any) : void {

    multipleCallbacks(firstCallback: (s: string) => void, secondCallback: (b: boolean) => boolean): void {
        firstCallback("hello world")

        let result: boolean = secondCallback(true)
        console.log("Resulting boolean: " + result)

var foo = new Foo()

// Single callback example.
// Just like with @RyanCavanaugh's approach, ensure the parameter(s) and return
// types match the declared types above in the `save()` method definition. number) => {
    console.log("Some number: " + newNumber)

    // This is optional, since "any" is the declared return type.
    return newNumber

// Multiple callbacks example.
// Each call is on a separate line for clarity.
// Note that `firstCallback()` has a void return type, while the second is boolean.
    (s: string) => {
         console.log("Some string: " + s)
    (b: boolean) => {
        console.log("Some boolean: " + b)
        let result = b && false

        return result

The multipleCallback() approach is very useful for things like network calls that may succeed or fail. Again assuming a network call example, when multipleCallbacks() is called, behavior for both a success and failure can be defined in one spot, which lends itself to greater clarity for future code readers.

Generally, in my experience, this approach lends itself to being more concise, less clutter, and greater clarity overall.

Good luck all!

How to move the cursor word by word in the OS X Terminal

Use Natural Text Editing preset!

enter image description here

Essentially it binds, among other key sequences, Option + LeftArrow to ^[b sequence and Option + RightArrow to ^[f

This works in fish and bash, as well as in psql terminal.

How do I turn a String into a InputStreamReader in java?

Same question as @Dan - why not StringReader ?

If it has to be InputStreamReader, then:

String charset = ...; // your charset
byte[] bytes = string.getBytes(charset);
ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
InputStreamReader isr = new InputStreamReader(bais);

Goal Seek Macro with Goal as a Formula

GoalSeek will throw an "Invalid Reference" error if the GoalSeek cell contains a value rather than a formula or if the ChangingCell contains a formula instead of a value or nothing.

The GoalSeek cell must contain a formula that refers directly or indirectly to the ChangingCell; if the formula doesn't refer to the ChangingCell in some way, GoalSeek either may not converge to an answer or may produce a nonsensical answer.

I tested your code with a different GoalSeek formula than yours (I wasn't quite clear whether some of the terms referred to cells or values).

For the test, I set:

  the GoalSeek cell  H18 = (G18^3)+(3*G18^2)+6
  the Goal cell      H32 =  11
  the ChangingCell   G18 =  0 

The code was:

Sub GSeek()
    With Worksheets("Sheet1")
        .Range("H18").GoalSeek _
        Goal:=.Range("H32").Value, _
    End With
End Sub

And the code produced the (correct) answer of 1.1038, the value of G18 at which the formula in H18 produces the value of 11, the goal I was seeking.

How to get local server host and port in Spring Boot?

You can get port info via

private String serverPort;

How to get a URL parameter in Express?

If you want to grab the query parameter value in the URL, follow below code pieces


If you want to grab the URL parameter using Express param function

Express param function to grab a specific parameter. This is considered middleware and will run before the route is called.

This can be used for validations or grabbing important information about item.

An example for this would be:

// parameter middleware that will run before the next routes
app.param('tagid', function(req, res, next, tagid) {

// check if the tagid exists
// do some validations
// add something to the tagid
var modified = tagid+ '123';

// save name to the request
req.tagid= modified;


// http://localhost:8080/api/tags/98
app.get('/api/tags/:tagid', function(req, res) {
// the tagid was found and is available in req.tagid
res.send('New tag id ' + req.tagid+ '!');

POST data in JSON format

Using the new FormData object (and other ES6 stuff), you can do this to turn your entire form into JSON:

let data = {};
let formdata = new FormData(theform);
for (let tuple of formdata.entries()) data[tuple[0]] = tuple[1];

and then just xhr.send(JSON.stringify(data)); like in Jan's original answer.

Sum values in foreach loop php

In your case IF you want to go with foreach loop than

$sum = 0;
foreach($group as $key => $value) {
   $sum += $value; 
echo $sum;

But if you want to go with direct sum of array than look on below for your solution :

$total = array_sum($group);

for only sum of array looping is time wasting.

array_sum — Calculate the sum of values in an array

$a = array(2, 4, 6, 8);
echo "sum(a) = " . array_sum($a) . "\n";

$b = array("a" => 1.2, "b" => 2.3, "c" => 3.4);
echo "sum(b) = " . array_sum($b) . "\n";

The above example will output:

sum(a) = 20
sum(b) = 6.9

How to echo text during SQL script execution in SQLPLUS

You can use SET ECHO ON in the beginning of your script to achieve that, however, you have to specify your script using @ instead of < (also had to add EXIT at the end):







sqlplus hr/oracle@orcl @/tmp/test.sql > /tmp/test.log







How to parse JSON data with jQuery / JavaScript?

var jsonP = "person" : [ { "id" : "1", "name" : "test1" },
  { "id" : "2", "name" : "test2" },
  { "id" : "3", "name" : "test3" },
  { "id" : "4", "name" : "test4" },
  { "id" : "5", "name" : "test5" } ];

var cand = document.getElementById("cand");
var json_arr = [];
    json_arr.push(key+' . '  + '<br>');
    cand.innerHTML = json_arr;

<div id="cand">

how to log in to mysql and query the database from linux terminal

In Ubuntu, all I have to do ran is sudo mysql in GNOME terminal and that's it. I can start making databases or query a data in table, etc.