Programs & Examples On #Directx 11

DirectX 11 is the 11th version of Microsoft's DirectX API, which is used to develop and handle tasks related to Multimedia, such as game programming, 3d visualizations and video on Microsoft platforms. DirectX 11 runs on Windows Vista, Windows 7, Windows 8, Windows 10, and Xbox One.

How to 'foreach' a column in a DataTable using C#?

In LINQ you could do something like:

foreach (var data in from DataRow row in dataTable.Rows
                     from DataColumn col in dataTable.Columns
                              row[col] != null
                          select row[col])
    // do something with data

How to install JDBC driver in Eclipse web project without facing java.lang.ClassNotFoundexception

What you should not do do (especially when working on a shared project)

Ok, after had the same issue and after reading some answers here and other places. it seems that putting external lib into WEB-INF/lib is not that good idea as it pollute webapp/JRE libs with server-specific libraries - for more information check this answer"

Another solution that i do NOT recommend is: to copy it into tomcat/lib folder. although this may work, it will be hard to manage dependency for a shared(git for example) project.

Good solution 1

Create vendor folder. put there all your external lib. then, map this folder as dependency to your project. in eclipse you need to

  1. add your folder to the build path
    1. Project Properties -> Java build path
    2. Libraries -> add external lib or any other solution to add your files/folder
  2. add your build path to deployment Assembly (reference)
    1. Project Properties -> Deployment Assembly
    2. Add -> Java Build Path Entries
    3. You should now see the list of libraries on your build path that you can specify for inclusion into your finished WAR.
    4. Select the ones you want and hit Finish.

Good solution 2

Use maven (or any alternative) to manage project dependency

AccessDenied for ListObjects for S3 bucket when permissions are s3:*

To allow permissions in s3 bucket go to the permissions tab in s3 bucket and in bucket policy change the action to this which will allow all actions to be performed:


Swift: print() vs println() vs NSLog()

To add to Rob's answer, since iOS 10.0, Apple has introduced an entirely new "Unified Logging" system that supersedes existing logging systems (including ASL and Syslog, NSLog), and also surpasses existing logging approaches in performance, thanks to its new techniques including log data compression and deferred data collection.

From Apple:

The unified logging system provides a single, efficient, performant API for capturing messaging across all levels of the system. This unified system centralizes the storage of log data in memory and in a data store on disk.

Apple highly recommends using os_log going forward to log all kinds of messages, including info, debug, error messages because of its much improved performance compared to previous logging systems, and its centralized data collection allowing convenient log and activity inspection for developers. In fact, the new system is likely so low-footprint that it won't cause the "observer effect" where your bug disappears if you insert a logging command, interfering the timing of the bug to happen.

Performance of Activity Tracing, now part of the new Unified Logging system

You can learn more about this in details here.

To sum it up: use print() for your personal debugging for convenience (but the message won't be logged when deployed on user devices). Then, use Unified Logging (os_log) as much as possible for everything else.

How to delete a whole folder and content?

The fastest and easiest way:

public static boolean deleteFolder(File removableFolder) {
        File[] files = removableFolder.listFiles();
        if (files != null && files.length > 0) {
            for (File file : files) {
                boolean success;
                if (file.isDirectory())
                    success = deleteFolder(file);
                else success = file.delete();
                if (!success) return false;
        return removableFolder.delete();

Can I draw rectangle in XML?

Use this code

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android=""
android:shape="rectangle" >

        android:topRightRadius="5dp" />

    <solid android:color="#Efffff" />

        android:color="#25aaff" />


Angular File Upload

Very easy and fastest method is using ng2-file-upload.

Install ng2-file-upload via npm. npm i ng2-file-upload --save

At first import module in your module.

import { FileUploadModule } from 'ng2-file-upload';

Add it to [imports] under @NgModule:
imports: [ ... FileUploadModule, ... ]


<input ng2FileSelect type="file" accept=".xml" [uploader]="uploader"/>

In your commponent ts:

import { FileUploader } from 'ng2-file-upload';
uploader: FileUploader = new FileUploader({ url: "api/your_upload", removeAfterUpload: false, autoUpload: true });

It`is simplest usage of this. To know all power of this see demo

Show week number with Javascript?

Martin Schillinger's version seems to be the strictly correct one.

Since I knew I only needed it to work correctly on business week days, I went with this simpler form, based on something I found online, don't remember where:

ISOWeekday = (0 == InputDate.getDay()) ? 7 : InputDate.getDay();
ISOCalendarWeek = Math.floor( ( ((InputDate.getTime() - (new Date(InputDate.getFullYear(),0,1)).getTime()) / 86400000) - ISOWeekday + 10) / 7 );

It fails in early January on days that belong to the previous year's last week (it produces CW = 0 in those cases) but is correct for everything else.

How to convert enum value to int?

public enum Tax {


private final int value;
    private Tax(int value) {
        this.value = value;

    public String toString() {
        return Integer.toString(value);

class Test {
    System.out.println(Tax.NONE);    //Just an example.

ActionBar text color

If you want to style the subtitle also then simply add this in your custom style.

<item name="android:subtitleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>

People who are looking to get the same result for AppCompat library then this is what I used:

<?xml version="1.0" encoding="utf-8"?>
<style name="CustomActivityTheme" parent="@style/Theme.AppCompat.Light.DarkActionBar">
        <item name="android:actionBarStyle">@style/MyActionBar</item>
        <item name="actionBarStyle">@style/MyActionBar</item>
        <!-- other activity and action bar styles here -->

    <!-- style for the action bar backgrounds -->
    <style name="MyActionBar" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="android:background">@drawable/actionbar_background</item>
        <item name="background">@drawable/actionbar_background</item>
        <item name="android:titleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
        <item name="android:subtitleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
        <item name="titleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
        <item name="subtitleTextStyle">@style/MyTheme.ActionBar.TitleTextStyle</item>
    <style name="MyTheme.ActionBar.TitleTextStyle" parent="@style/TextAppearance.AppCompat.Widget.ActionBar.Title">
        <item name="android:textColor">@color/color_title</item>

adding classpath in linux

I don't like setting CLASSPATH. CLASSPATH is a global variable and as such it is evil:

  • If you modify it in one script, suddenly some java programs will stop working.
  • If you put there the libraries for all the things which you run, and it gets cluttered.
  • You get conflicts if two different applications use different versions of the same library.
  • There is no performance gain as libraries in the CLASSPATH are not shared - just their name is shared.
  • If you put the dot (.) or any other relative path in the CLASSPATH that means a different thing in each place - that will cause confusion, for sure.

Therefore the preferred way is to set the classpath per each run of the jvm, for example:

java -Xmx500m -cp ".:../somejar.jar:../mysql-connector-java-5.1.6-bin.jar"    "folder.subfolder../dit1/some.xml

If it gets long the standard procedure is to wrap it in a bash or batch script to save typing.

Browser Caching of CSS files

Unless you've messed with your server, yes it's cached. All the browsers are supposed to handle it the same. Some people (like me) might have their browsers configured so that it doesn't cache any files though. Closing the browser doesn't invalidate the file in the cache. Changing the file on the server should cause a refresh of the file however.

Unable to Install Any Package in Visual Studio 2015

I am using Visual Studio 2015 Update 3 and I managed to reproduce this error (despite Update 3 allegedly containing a fix).

As suggested above, a reliable fix is to do the following... 1) Exit Visual Studio, 2) Delete the packages folder, 3) Restart VS.

But... if you don't want to immediately exit VS for some reason, I was still able to add/remove packages from all projects by choosing the 'Manage NuGet Packages for Solution' option, rather than the individual Project with the issue.

Get absolute path of initially run script

__FILE__ constant will give you absolute path to current file.


The question was changed to ask how to retrieve the initially executed script instead of the currently running script. The only (??) reliable way to do that is to use the debug_backtrace function.

$stack = debug_backtrace();
$firstFrame = $stack[count($stack) - 1];
$initialFile = $firstFrame['file'];

An exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll

An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll

    private const string strconneciton = "Data Source=.;Initial Catalog=Employees;Integrated Security=True";
    SqlConnection con = new SqlConnection(strconneciton);

    private void button1_Click(object sender, EventArgs e)

        SqlCommand cmd = new SqlCommand("insert into EmployeeData (Name,S/O,Address,Phone,CellNo,CNICNO,LicenseNo,LicenseDistrict,LicenseValidPhoto,ReferenceName,ReferenceContactNo) values ( '" + textName.Text + "','" + textSO.Text + "','" + textAddress.Text + "','" + textPhone.Text + "','" + textCell.Text + "','" + textCNIC.Text + "','" + textLicenseNo.Text + "','" + textLicenseDistrict.Text + "','" + textLicensePhoto.Text + "','" + textReferenceName.Text + "','" + textContact.Text + "' )", con);

error: Libtool library used but 'LIBTOOL' is undefined

For mac it's simple:

brew install libtool

Git log to get commits only for a specific branch

BUT I would like to avoid the need of knowing the other branches names.

I don't think this is possible: a branch in Git is always based on another one or at least on another commit, as explained in "git diff doesn't show enough":

enter image description here

You need a reference point for your log to show the right commits.

As mentioned in "GIT - Where did I branch from?":

branches are simply pointers to certain commits in a DAG

So even if git log master..mybranch is one answer, it would still show too many commits, if mybranch is based on myotherbranch, itself based on master.

In order to find that reference (the origin of your branch), you can only parse commits and see in which branch they are, as seen in:

Changing line colors with ggplot()

color and fill are separate aesthetics. Since you want to modify the color you need to use the corresponding scale:

d + scale_color_manual(values=c("#CC6666", "#9999CC"))

is what you want.

Importing JSON into an Eclipse project

You should take the json implementation from here : .

  • Download the *.jar
  • Add it to the classpath (right-click on the project, Properties->Libraries and add new JAR.)

Reading and writing binary file

If you want to do this the C++ way, do it like this:

#include <fstream>
#include <iterator>
#include <algorithm>

int main()
    std::ifstream input( "C:\\Final.gif", std::ios::binary );
    std::ofstream output( "C:\\myfile.gif", std::ios::binary );

        std::istreambuf_iterator<char>( ),

If you need that data in a buffer to modify it or something, do this:

#include <fstream>
#include <iterator>
#include <vector>

int main()
    std::ifstream input( "C:\\Final.gif", std::ios::binary );

    // copies all data into buffer
    std::vector<unsigned char> buffer(std::istreambuf_iterator<char>(input), {});


Android notification is not showing

I think that you forget the

addAction(int icon, CharSequence title, PendingIntent intent)

Look here: Add Action

rails 3 validation on uniqueness on multiple attributes

Dont work for me, need to put scope in plural

validates_uniqueness_of :teacher_id, :scopes => [:semester_id, :class_id]

JSON to PHP Array using file_get_contents

Check some typo ','

$jsonD = '{
                    "adate":"2 Hours ago",
                    "adesc":"test desc",
                    "adate":"20 Hours ago",
                    "adesc":"test desc1",
                    "adate":"1 Days ago",
                    "adesc":"test123 desc",
                    "adate":"2 Days ago",
                    "adesc":"test12345 desc",

$parseJ = json_decode($jsonD,true);


Most efficient way to create a zero filled JavaScript array?

ES6 solution:

[ Array(5)].map(x => 0); // [0, 0, 0, 0, 0]

$.focus() not working

Found a solution elsewhere on the net...


did not work.


did work.

QED symbol in latex

As described here, you can redefine the command \qedsymbol, in your case - to \blacksquare:


This works both with \qed command and proof environment.

submit form on click event using jquery

it's because the name of the submit button is named "submit", change it to anything but "submit", try "submitme" and retry it. It should then work.

TypeError: expected str, bytes or os.PathLike object, not _io.BufferedReader

I think it has to do with your second element in storbinary. You are trying to open file, but it is already a pointer to the file you opened in line file = open(local_path,'rb'). So, try to use ftp.storbinary("STOR " + i, file).

Get the length of a String

Right now (in Swift 2.3) if you use:


the method will return a "Distance" type, if you need the method to return an Integer you should type cast like so:

var count = myString.characters.count as Int

How to: "Separate table rows with a line"

If you don't want to use CSS try this one between your rows:

    <td class="divider"><hr /></td>


c# - How to get sum of the values from List?

Use Sum()

 List<string> foo = new List<string>();

 Console.Write(foo.Sum(x => Convert.ToInt32(x)));



Android: making a fullscreen application

According to this document, add the following code to onCreate

getWindow().getDecorView().setSystemUiVisibility(SYSTEM_UI_FLAG_IMMERSIVE_STICKY |

jQuery: Slide left and slide right

You can always just use jQuery to add a class, .addClass or .toggleClass. Then you can keep all your styles in your CSS and out of your scripts.

Replace a string in shell script using a variable

I had a similar requirement to this but my replace var contained an ampersand. Escaping the ampersand like this solved my problem:

replace="salt & pepper"
echo "pass the salt" | sed "s/salt/${replace/&/\&}/g"

Changing font size and direction of axes text in ggplot2

Use theme():

d <- data.frame(x=gl(10, 1, 10, labels=paste("long text label ", letters[1:10])), y=rnorm(10))
ggplot(d, aes(x=x, y=y)) + geom_point() +
theme(text = element_text(size=20))

How to use timeit module

# ????????? ????? ?????

def gen_prime(x):
    multiples = []
    results = []
    for i in range(2, x+1):
        if i not in multiples:
            for j in range(i*i, x+1, i):

    return results

import timeit

# ???????? ?????

start_time = timeit.default_timer()
print(timeit.default_timer() - start_time)

# start_time = timeit.default_timer()
# gen_prime(1001)
# print(timeit.default_timer() - start_time)

WCF Service , how to increase the timeout?

The best way is to change any setting you want in your code.

Check out the below example:

using(WCFServiceClient client = new WCFServiceClient ())
    client.Endpoint.Binding.SendTimeout = new TimeSpan(0, 1, 30);

SQLSTATE[42S22]: Column not found: 1054 Unknown column - Laravel

You don't have a field named user_email in the members table ... as for why, I'm not sure as the code "looks" like it should try to join on different fields

Does the Auth::attempt method perform a join of the schema? Run grep -Rl 'class Auth' /path/to/framework and find where the attempt method is and what it does.

UIAlertController custom font, size, color

I'm using it.

[[UIView appearanceWhenContainedIn:[UIAlertController class], nil] setTintColor:[UIColor blueColor]];

Add one line (AppDelegate) and works for all UIAlertController.

How to resolve TypeError: Cannot convert undefined or null to object

Below snippet is sufficient to understand how I encountered the same issue but in a different scenario and how I solved it using the guidance in the accepted answer. In my case I was trying to log the keys of object present in the 0th index of the 'defaultViewData' array using Object.keys() method.

defaultViewData = [{"name": "DEFAULT_VIEW_PLP","value": {"MSH25": "LIST"}}] 

console.log('DEFAULT_VIEW', Object.keys(this.props.defaultViewData[0]));

The console.log was not getting printed and I was getting the same error as posted in this question. To prevent that error I added below condition

    if(this.props.defaultViewData[0]) {
  console.log('DEFAULT_VIEW', Object.keys(this.props.defaultViewData[0]));

Adding this check ensured that I didn't get this error. I hope this helps for someone.

Note: This is React.js code. (although to understand the problem it doesn't matter).

How to close a GUI when I push a JButton?

You may use Window#dispose() method to release all of the native screen resources, subcomponents, and all of its owned children.

The System.exit(0) will terminates the currently running Java Virtual Machine.

C# Base64 String to JPEG Image

So with the code you have provided.

var bytes = Convert.FromBase64String(resizeImage.Content);
using (var imageFile = new FileStream(filePath, FileMode.Create))
    imageFile.Write(bytes ,0, bytes.Length);

How to list all installed packages and their versions in Python?

yes! you should be using pip as your python package manager ( )

with pip installed packages, you can do a

pip freeze

and it will list all installed packages. You should probably also be using virtualenv and virtualenvwrapper. When you start a new project, you can do

mkvirtualenv my_new_project

and then (inside that virtualenv), do

pip install all_your_stuff

This way, you can workon my_new_project and then pip freeze to see which packages are installed for that virtualenv/project.

for example:

?  ~  mkvirtualenv yo_dude
New python executable in yo_dude/bin/python
Installing setuptools............done.
Installing pip...............done.
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/predeactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/postdeactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/preactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/postactivate
virtualenvwrapper.user_scripts creating /Users/aaylward/dev/virtualenvs/yo_dude/bin/get_env_details

(yo_dude)?  ~  pip install django
Downloading/unpacking django
  Downloading Django-1.4.1.tar.gz (7.7Mb): 7.7Mb downloaded
  Running egg_info for package django

Installing collected packages: django
  Running install for django
    changing mode of build/scripts-2.7/ from 644 to 755

    changing mode of /Users/aaylward/dev/virtualenvs/yo_dude/bin/ to 755
Successfully installed django
Cleaning up...

(yo_dude)?  ~  pip freeze

(yo_dude)?  ~  

or if you have a python package with a requirements.pip file,

mkvirtualenv my_awesome_project
pip install -r requirements.pip
pip freeze

will do the trick

WPF popup window

Simply show a new window with two buttons. Add property to contain user result.

Failed to auto-configure a DataSource: 'spring.datasource.url' is not specified

Since you have added both mongodb and data-jpa dependencies in your pom.xml file, it was creating a dependency conflict like below


Try removing jpa dependency and run. It should work fine.

How many bits or bytes are there in a character?

There are 8 bits in a byte (normally speaking in Windows).

However, if you are dealing with characters, it will depend on the charset/encoding. Unicode character can be 2 or 4 bytes, so that would be 16 or 32 bits, whereas Windows-1252 sometimes incorrectly called ANSI is only 1 bytes so 8 bits.

In Asian version of Windows and some others, the entire system runs in double-byte, so a character is 16 bits.


Per Matteo's comment, all contemporary versions of Windows use 16-bits internally per character.

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

react-native - Fit Image in containing View, not the whole screen size

If you know the aspect ratio for example, if your image is square you can set either the height or the width to fill the container and get the other to be set by the aspectRatio property

Here is the style if you want the height be set automatically:

    width: '100%',
    height: undefined,
    aspectRatio: 1,

Note: height must be undefined

How to use a variable from a cursor in the select statement of another cursor in pl/sql

You can certainly do something like

SQL> ed
Wrote file afiedt.buf

  1  begin
  2    for d in (select * from dept)
  3    loop
  4      for e in (select * from emp where deptno=d.deptno)
  5      loop
  6        dbms_output.put_line( 'Employee ' || e.ename ||
  7                              ' in department ' || d.dname );
  8      end loop;
  9    end loop;
 10* end;
SQL> /
Employee CLARK in department ACCOUNTING
Employee KING in department ACCOUNTING
Employee MILLER in department ACCOUNTING
Employee smith in department RESEARCH
Employee JONES in department RESEARCH
Employee SCOTT in department RESEARCH
Employee ADAMS in department RESEARCH
Employee FORD in department RESEARCH
Employee ALLEN in department SALES
Employee WARD in department SALES
Employee MARTIN in department SALES
Employee BLAKE in department SALES
Employee TURNER in department SALES
Employee JAMES in department SALES

PL/SQL procedure successfully completed.

Or something equivalent using explicit cursors.

SQL> ed
Wrote file afiedt.buf

  1  declare
  2    cursor dept_cur
  3        is select *
  4             from dept;
  5    d dept_cur%rowtype;
  6    cursor emp_cur( p_deptno IN dept.deptno%type )
  7        is select *
  8             from emp
  9            where deptno = p_deptno;
 10    e emp_cur%rowtype;
 11  begin
 12    open dept_cur;
 13    loop
 14      fetch dept_cur into d;
 15      exit when dept_cur%notfound;
 16      open emp_cur( d.deptno );
 17      loop
 18        fetch emp_cur into e;
 19        exit when emp_cur%notfound;
 20        dbms_output.put_line( 'Employee ' || e.ename ||
 21                              ' in department ' || d.dname );
 22      end loop;
 23      close emp_cur;
 24    end loop;
 25    close dept_cur;
 26* end;
 27  /
Employee CLARK in department ACCOUNTING
Employee KING in department ACCOUNTING
Employee MILLER in department ACCOUNTING
Employee smith in department RESEARCH
Employee JONES in department RESEARCH
Employee SCOTT in department RESEARCH
Employee ADAMS in department RESEARCH
Employee FORD in department RESEARCH
Employee ALLEN in department SALES
Employee WARD in department SALES
Employee MARTIN in department SALES
Employee BLAKE in department SALES
Employee TURNER in department SALES
Employee JAMES in department SALES

PL/SQL procedure successfully completed.

However, if you find yourself using nested cursor FOR loops, it is almost always more efficient to let the database join the two results for you. After all, relational databases are really, really good at joining. I'm guessing here at what your tables look like and how they relate based on the code you posted but something along the lines of

            FROM all_users,
           WHERE length(all_users.username) = 3
             AND all_users.username = org.username )
  <<do something>>

Java replace issues with ' (apostrophe/single quote) and \ (backslash) together

If you want to use it in JavaScript then you can use


But in Java


will work perfectly.

SP: special character

Otherwise you can use Apache's EscapeUtil. It will solve your problem.

Docker-compose: node_modules not present in a volume after npm install succeeds

You can try something like this in your Dockerfile:

FROM node:0.12
WORKDIR /worker
CMD bash ./

Then you should use the Volume like this:

  - worker/:/worker:rw

The startscript should be a part of your worker repository and looks like this:

npm install
npm start

So the node_modules are a part of your worker volume and gets synchronized and the npm scripts are executed when everything is up.

Android, How can I Convert String to Date?

It could be a good idea to be careful with the Locale upon which c.getTime().toString(); depends.

One idea is to store the time in seconds (e.g. UNIX time). As an int you can easily compare it, and then you just convert it to string when displaying it to the user.

Type Checking: typeof, GetType, or is?

if (c is UserControl) c.Enabled = enable;

Setting width and height

Use this, it works fine.

<canvas id="totalschart" style="height:400px;width: content-box;"></canvas>

and under options,


Plotting multiple lines, in different colors, with pandas dataframe

Another simple way is to use the pivot function to format the data as you need first.

df.plot() does the rest

df = pd.DataFrame([
    ['red', 0, 0],
    ['red', 1, 1],
    ['red', 2, 2],
    ['red', 3, 3],
    ['red', 4, 4],
    ['red', 5, 5],
    ['red', 6, 6],
    ['red', 7, 7],
    ['red', 8, 8],
    ['red', 9, 9],
    ['blue', 0, 0],
    ['blue', 1, 1],
    ['blue', 2, 4],
    ['blue', 3, 9],
    ['blue', 4, 16],
    ['blue', 5, 25],
    ['blue', 6, 36],
    ['blue', 7, 49],
    ['blue', 8, 64],
    ['blue', 9, 81],
], columns=['color', 'x', 'y'])

df = df.pivot(index='x', columns='color', values='y')



pivot effectively turns the data into:

enter image description here

How to format strings using printf() to get equal length in the output

There's also the rather low-tech solution of counting adding spaces by hand to make your messages line up. Nothing prevents you from including a few trailing spaces in your message strings.

Google Maps Android API v2 Authorization failure

Also check this post: Google Map Android Api V2 Sample Code not working, if you are completely sure you did the right steps then follow the second answer, the authentication gets cached somewhere, try to uninstall the application manually (just like you do with a normal application) then "Run" again the project

How to select rows for a specific date, ignoring time in SQL Server

I know it's been a while on this question, but I was just looking for the same answer and found this seems to be the simplest solution:

select * from sales where datediff(dd, salesDate, '20101111') = 0

I actually use it more to find things within the last day or two, so my version looks like this:

select * from sales where datediff(dd, salesDate, getdate()) = 0

And by changing the 0 for today to a 1 I get yesterday's transactions, 2 is the day before that, and so on. And if you want everything for the last week, just change the equals to a less-than-or-equal-to:

select * from sales where datediff(dd, salesDate, getdate()) <= 7

Submitting the value of a disabled input field

I know this is old but I just ran into this problem and none of the answers are suitable. nickf's solution works but it requires javascript. The best way is to disable the field and still pass the value is to use a hidden input field to pass the value to the form. For example,

<input type="text" value="22.2222" disabled="disabled" />
<input type="hidden" name="lat" value="22.2222" />

This way the value is passed but the user sees the greyed out field. The readonly attribute does not gray it out.

Select the values of one property on all objects of an array in PowerShell

I think you might be able to use the ExpandProperty parameter of Select-Object.

For example, to get the list of the current directory and just have the Name property displayed, one would do the following:

ls | select -Property Name

This is still returning DirectoryInfo or FileInfo objects. You can always inspect the type coming through the pipeline by piping to Get-Member (alias gm).

ls | select -Property Name | gm

So, to expand the object to be that of the type of property you're looking at, you can do the following:

ls | select -ExpandProperty Name

In your case, you can just do the following to have a variable be an array of strings, where the strings are the Name property:

$objects = ls | select -ExpandProperty Name

Codeigniter $this->input->post() empty while $_POST is working correctly

My issue was with an ajax call. I was using this:

type: 'posts',

instead of

type: 'post',

Syntax, D'oh!

How to add title to seaborn boxplot

For a single boxplot:

import seaborn as sb

For more boxplot in the same plot:

import seaborn as sb


import seaborn as sb
myarray=[78.195229, 59.104538, 19.884109, 25.941648, 72.234825, 82.313911]

How to get EditText value and display it on screen through TextView?

    new View.OnClickListener()
        public void onClick(View view)
            String s1=tt.getText().toString();

How to open link in new tab on html?

You could do it like this:

<a href="" target="_blank" rel="noopener noreferrer">Open</a>

Originally was:

<a href=""></a>

Also look at the following url on MDN for more information about security and privacy:

which in turn has a link to a good article named Target="_blank" - the most underestimated vulnerability ever:

Count the number of occurrences of each letter in string


#define filename "somefile.txt"

int main()
    FILE *fp;
    int count[26] = {0}, i, c;  
    char ch;
    char alpha[27] = "abcdefghijklmnopqrstuwxyz";
    fp = fopen(filename,"r");
    if(fp == NULL)
        printf("file not found\n");
    while( (ch = fgetc(fp)) != EOF) {
        c = 0;
        while(alpha[c] != '\0') {

            if(alpha[c] == ch) {
    for(i = 0; i<26;i++) {
        printf("character %c occured %d number of times\n",alpha[i], count[i]);
    return 0;

Removing double quotes from a string in Java

You can just go for String replace method.-

line1 = line1.replace("\"", "");

Display a message in Visual Studio's output window when not debug mode?

The Trace.WriteLine method is a conditionally compiled method. That means that it will only be executed if the TRACE constant is defined when the code is compiled. By default in Visual Studio, TRACE is only defined in DEBUG mode.

Right Click on the Project and Select Properties. Go to the Compile tab. Select Release mode and add TRACE to the defined preprocessor constants. That should fix the issue for you.

Convert an image (selected by path) to base64 string

You can convert it like this

  string test = @"C:/image/1.gif";
  byte[] bytes = System.Text.ASCIIEncoding.ASCII.GetBytes(test);
  string base64String = System.Convert.ToBase64String(bytes);
  Console.WriteLine("Base 64 string: " + base64String);



Return HTML content as a string, given URL. Javascript Function

after you get the response just do call this function to append data to your body element

function createDiv(responsetext)
    var _body = document.getElementsByTagName('body')[0];
    var _div = document.createElement('div');
    _div.innerHTML = responsetext;

@satya code modified as below

function httpGet(theUrl)
    if (window.XMLHttpRequest)
    {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    {// code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
    }"GET", theUrl, false);

How to install latest version of openssl Mac OS X El Capitan

This is an old question but still answering it in present-day context as many of the above answers may not work now.

The problem is that the Path is still pointing to the old version. Two solutions can be provided for resolution :

  1. Uninstall old version of openssl package brew uninstall openssl and then reinstall the new version : brew install openssl
  2. point the PATH to the new version of openssl.First install the new version and now(or if) you have installed the latest version, point the path to it: echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.bash_profile

How do I ignore an error on 'git pull' about my local changes would be overwritten by merge?

I had a special case of this: I had a file with --assume-unchanged on it. It was hard to locate, as the git status command was not showing any changes

How to retrieve form values from HTTPPOST, dictionary or?

You could have your controller action take an object which would reflect the form input names and the default model binder will automatically create this object for you:

public ActionResult SubmitAction(SomeModel model)
    var value1 = model.SimpleProp1;
    var value2 = model.SimpleProp2;
    var value3 = model.ComplexProp1.SimpleProp1;

    ... return something ...

Another (obviously uglier) way is:

public ActionResult SubmitAction()
    var value1 = Request["SimpleProp1"];
    var value2 = Request["SimpleProp2"];
    var value3 = Request["ComplexProp1.SimpleProp1"];

    ... return something ...

RS256 vs HS256: What's the difference?

short answer, specific to OAuth2,

  • HS256 user client secret to generate the token signature and same secret is required to validate the token in back-end. So you should have a copy of that secret in your back-end server to verify the signature.
  • RS256 use public key encryption to sign the token.Signature(hash) will create using private key and it can verify using public key. So, no need of private key or client secret to store in back-end server, but back-end server will fetch the public key from openid configuration url in your tenant (https://[tenant]/.well-known/openid-configuration) to verify the token. KID parameter inside the access_toekn will use to detect the correct key(public) from openid-configuration.

How do I view / replay a chrome network debugger har file saved with content?

Edit: Harhar is now open source. I have updated the URL below.

If you use an Avalanche load generator, you can use Harhar to replay a HAR file at very high load:

This tool handles the "content" you use when you "Save as HAR with content."

Connect to SQL Server database from Node.js

I am not sure did you see this list of MS SQL Modules for Node JS

Share your experience after using one if possible .

Good Luck

On Windows, running "import tensorflow" generates No module named "_pywrap_tensorflow" error

In case you are trying to install tensorflow GPU in Windows, you can find this easy interesting tutorial.

Note: If you are using PyCharm for example, you have to change the interpreter to the created conda environment.

Getting Current date, time , day in laravel

How about

    $date = Carbon::now();
    return $date->toArray();

will give you

  "year": 2019,
  "month": 1,
  "day": 27,
  "dayOfWeek": 0,
  "dayOfYear": 26,
  "hour": 10,
  "minute": 28,
  "second": 55,
  "englishDayOfWeek": "Sunday",
  "micro": 967721,
  "timestamp": 1548570535,
  "formatted": "2019-01-27 10:28:55",
  "timezone": {
    "timezone_type": 3,
    "timezone": "Asia/Dubai"

The same props are accessible through

    return [
             'date' => $date->format('Y-m-d'),
              'year' => $date->year,
              'month' => $date->month,
              'day' => $date->day,
              'hour' => $date->hour,
              'isSaturday' => $date->isSaturday(),

Print Pdf in C#

Another approach, if you simply wish to print a PDF file programmatically, is to use the LPR command:

LPR is available on newer versions of Windows too (e.g. Vista/7), but you need to enable it in the Optional Windows Components.

For example:

Process.Start("LPR -S printerdnsalias -P raw C:\files\file.pdf");

You can also use the printer IP address instead of the alias.

This assumes that your printer supports PDF Direct Printing otherwise this will only work for PostScript and ASCII files. Also, the printer needs to have a network interface installed and you need to know it's IP address or alias.

java.util.Date format SSSSSS: if not microseconds what are the last 3 digits?

SSSSSS is microseconds. Let us say the time is 10:30:22 (Seconds 22) and 10:30:22.1 would be 22 seconds and 1/10 of a second . Extending the same logic , 10:32.22.000132 would be 22 seconds and 132/1,000,000 of a second, which is nothing but microseconds.

PHP 7: Missing VCRUNTIME140.dll

If you've followed Adam's instructions and you're still getting this error make sure you've installed the right variants (x86 or x64).

I had VC14x64 with PHP7x86 and I still got this error. Changing PHP7 to x64 fixed it. It's easy to miss you accidentally installed the wrong version.

How to add spacing between UITableViewCell

My situation was i used custom UIView to viewForHeader in section also heightForHeader in section return constant height say 40, issue was when there is no data all header views were touched to each other. so i wanted to space between the section in absent of data so i fixed by just changing "tableview style" plane to "Group".and it worked for me.

IBOutlet and IBAction

The traditional way to flag a method so that it will appear in Interface Builder, and you can drag a connection to it, has been to make the method return type IBAction. However, if you make your method void, instead (IBAction is #define'd to be void), and provide an (id) argument, the method is still visible. This provides extra flexibility, al

All 3 of these are visible from Interface Builder:

-(void) someMethod1:(id) sender; 
-(IBAction) someMethod2; 
-(IBAction) someMethod3:(id) sender;

See Apple's Interface Builder User Guide for details, particularly the section entitled Xcode Integration.

React component initialize state from props

set the state data inside constructor like this

constructor(props) {
    this.state = {
      productdatail: this.props.productdetailProps

it will not going to work if u set in side componentDidMount() method through props.

Using LIKE in an Oracle IN clause

select * from tbl
 where exists (select 1 from all_likes where all_likes.value = substr(tbl.my_col,0, length(tbl.my_col)))

Downloading a picture via urllib and python

import urllib
f = open('00000001.jpg','wb')

How to put a jpg or png image into a button in HTML

Use <button> element instead of <input type=button />

How to use index in select statement?

By using the column that the index is applied to within your conditions, it will be included automatically. You do not have to use it, but it will speed up queries when it is used.

SELECT * FROM TABLE WHERE attribute = 'value'

Will use the appropriate index.

how to concat two columns into one with the existing column name in mysql?

I am a novice and I did it this way:

Create table Name1
F_Name varchar(20),
L_Name varchar(20),

Insert into Name1
('Tom', 'Bombadil', 32),
('Danny', 'Fartman', 43),
('Stephine', 'Belchlord', 33),
('Corry', 'Smallpants', 95)

Update Name1
Set F_Name = CONCAT(F_Name, ' ', L_Name)

Alter Table Name1
Drop column L_Name

Update Table_Name
Set F_Name

Split output of command by columns using Bash?

Your command

ps | egrep 11383 | cut -d" " -f 4

misses a tr -s to squeeze spaces, as unwind explains in his answer.

However, you maybe want to use awk, since it handles all of these actions in a single command:

ps | awk '/11383/ {print $4}'

This prints the 4th column in those lines containing 11383. If you want this to match 11383 if it appears in the beginning of the line, then you can say ps | awk '/^11383/ {print $4}'.

Importing files from different folder

Instead of just doing an import ..., do this :

from <MySubFolder> import <MyFile>

MyFile is inside the MySubFolder.

C# - Winforms - Global Variables

yes you can by using static class. like this:

static class Global
    private static string _globalVar = "";

    public static string GlobalVar
        get { return _globalVar; }
        set { _globalVar = value; }

and for using any where you can write:

GlobalClass.GlobalVar = "any string value"

Meaning of = delete after function declaration

This is new thing in C++ 0x standards where you can delete an inherited function.

What is the current directory in a batch file?

It is the directory from where you run the command to execute your batch file.

As mentioned in the above answers you can add the below command to your script to verify:

> set current_dir=%cd%
> echo %current_dir%  

Keyboard shortcuts are not active in Visual Studio with Resharper installed

This worked for me.

Setting to Resharper / Options / KeyBoard & Menus / None / Apply and Save

and then

Resharper / Options / KeyBoard & Menus / Set to Visual Studio / Apply and Save

Object of class stdClass could not be converted to string

In General to get rid of

Object of class stdClass could not be converted to string.

try to use echo '<pre>'; print_r($sql_query); for my SQL Query got the result as

stdClass Object
    [num_rows] => 1
    [row] => Array
            [option_id] => 2
            [type] => select
            [sort_order] => 0

    [rows] => Array
            [0] => Array
                    [option_id] => 2
                    [type] => select
                    [sort_order] => 0



In order to acces there are different methods E.g.: num_rows, row, rows

echo $query2->row['option_id'];

Will give the result as 2

Change image size via parent div

I am doing this way:

<div class="card-logo">
    <img height="100%" width="100%" src="http://someimage.jpg">

and CSS:

.card-logo {
    width: 20%;

I prefer this way, as if I need to upscale - I can use 150% as well

jQuery: How can I create a simple overlay?

Here's a fully encapsulated version which adds an overlay (including a share button) to any IMG element where data-photo-overlay='true.



<img id="my-photo-id" src="" alt="Photo" data-photo-overlay="true" />


#photoOverlay {
    background: #ccc;
    background: rgba(0, 0, 0, .5);
    display: none;
    height: 50px;
    left: 0;
    position: absolute;
    text-align: center;
    top: 0;
    width: 50px;
    z-index: 1000;

#photoOverlayShare {
    background: #fff;
    border: solid 3px #ccc;
    color: #ff6a00;
    cursor: pointer;
    display: inline-block;
    font-size: 14px;
    margin-left: auto;
    margin: 15px;
    padding: 5px;
    position: absolute;
    left: calc(100% - 100px);
    text-transform: uppercase;
    width: 50px;


(function () {
    // Add photo overlay hover behavior to selected images

    // Create photo overlay elements
    var _isPhotoOverlayDisplayed = false;
    var _photoId;
    var _photoOverlay = $("<div id='photoOverlay'></div>");
    var _photoOverlayShareButton = $("<div id='photoOverlayShare'>Share</div>");

    // Add photo overlay events

    // Add photo overlay elements to document

    // Show photo overlay
    function showPhotoOverlay(e) {
        // Get sender 
        var sender = $( || e.srcElement);

        // Check to see if overlay is already displayed
        if (!_isPhotoOverlayDisplayed) {
            // Set overlay properties based on sender

            // Position overlay on top of photo
            if (sender[0].x) {
                _photoOverlay.css("left", sender[0].x + "px");
                _photoOverlay.css("top", sender[0].y) + "px";
            else {
                // Handle IE incompatibility
                _photoOverlay.css("left", sender.offset().left);
                _photoOverlay.css("top", sender.offset().top);

            // Get photo Id
            _photoId = sender.attr("id");

            // Show overlay
            _photoOverlay.animate({ opacity: "toggle" });
            _isPhotoOverlayDisplayed = true;

    // Hide photo overlay
    function hidePhotoOverlay(e) {
        if (_isPhotoOverlayDisplayed) {
            _photoOverlay.animate({ opacity: "toggle" });
            _isPhotoOverlayDisplayed = false;

    // Share photo
    function sharePhoto() {
        alert("TODO: Share photo. [PhotoId = " + _photoId + "]");

Accessing a value in a tuple that is in a list

You can also use sequence unpacking with zip:

L = [(1,2),(2,3),(4,5),(3,4),(6,7),(6,7),(3,8)]

_, res = zip(*L)


# (2, 3, 5, 4, 7, 7, 8)

This also creates a tuple _ from the discarded first elements. Extracting only the second is possible, but more verbose:

from itertools import islice

res = next(islice(zip(*L), 1, None))

Secure random token in Node.js has a method for it :)

var value = crypto.random(/* desired length */)

Message "Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout"

You can also get timeout errors based on silly typos. e.g This seemingly innocuous mistake:

describe('Something', () => {
  it('Should do something', () => {

  it('Should do nothing', something_that_does_not_exist => {

Produces the following error:

FAIL src/TestNothing.spec.js (5.427s)
  ? Something › Should do nothing

    Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout.
      at node_modules/jest-jasmine2/build/queue_runner.js:68:21
      at Timeout.callback [as _onTimeout] (node_modules/jsdom/lib/jsdom/browser/Window.js:678:19)

Whilst the code sample posted doesn't suffer from this it might be a cause of failures elsewhere. Also note that I'm not setting a timeout for anything anywhere - either here or in the config. The 5000ms is just the default setting.

Search a string in a file and delete it from this file by Shell Script

sed -i '/pattern/d' file

Use 'd' to delete a line. This works at least with GNU-Sed.

If your Sed doesn't have the option, to change a file in place, maybe you can use an intermediate file, to store the modification:

sed '/pattern/d' file > tmpfile && mv tmpfile file

Writing directly to the source usually doesn't work: sed '/pattern/d' file > file so make a copy before trying out, if you doubt it.

CSS-Only Scrollable Table with fixed headers

if it gets rock hard where all the mentioned solutions don't work (as it got for me), try a two-tabled solutioned, as I explained in this answer

How to Insert Double or Single Quotes

To Create New Quoted Values from Unquoted Values

  • Column A contains the names.
  • Put the following formula into Column B = """" & A1 & """"
  • Copy Column B and Paste Special -> Values

Using a Custom Function

Public Function Enquote(cell As Range, Optional quoteCharacter As String = """") As Variant
    Enquote = quoteCharacter & cell.value & quoteCharacter
End Function


=OfficePersonal.xls!Enquote(A1, "'")

To get permanent quoted strings, you will have to copy formula values and paste-special-values.

Error: "Could Not Find Installable ISAM"

I used this to update a excel 12 xlsx file

        System.Data.OleDb.OleDbConnection MyConnection;
        System.Data.OleDb.OleDbCommand myCommand = new System.Data.OleDb.OleDbCommand();
        MyConnection = new System.Data.OleDb.OleDbConnection("provider=Microsoft.ACE.OLEDB.12.0;Data Source='D:\\Programming\\Spreadsheet-Current.xlsx';Extended Properties='Excel 12.0;HDR=YES;';");
        myCommand.Connection = MyConnection;
        string sql = "Update [ArticlesV2$] set [ID]='Test' where [ActualPageId]=114";// 
        myCommand.CommandText = sql;

ERROR: Sonar server 'http://localhost:9000' can not be reached

You should configure the sonar-runner to use your existing SonarQube server. To do so, you need to update its conf/ file and specify the SonarQube server URL, username, password, and JDBC URL as well. See for details.

If you don't yet have an up and running SonarQube server, then you can launch one locally (with the default configuration) - it will bind to http://localhost:9000 and work with the default sonar-runner configuration. See for details on how to get started with the SonarQube server.

Git status shows files as changed even though contents are the same

In my case, files were exactly the same (content, line endings, filemodes, md5 checksum, everything), yet were still visible in git status.

What helped was

# Garbage collect stuffs from .git
git gc

# commit stuff
git add . 
git commit -m "temporary" 

# this doesn't change contents
git reset HEAD^1 --soft    

After that, git status showed only one editted file that I editted.

Evaluate if list is empty JSTL

There's also the function tags, a bit more flexible:

<%@ taglib uri="" prefix="fn" %>
<c:if test="${fn:length(list) > 0}">

And here's the tag documentation.

Find all stored procedures that reference a specific column in some table

You can use the below query to identify the values. But please keep in mind that this will not give you the results from encrypted stored procedure.

FROM syscomments comments
    ,sys.objects objects
WHERE = objects.object_id
    AND TEXT LIKE '%CreatedDate%'

Question mark characters displaying within text, why is this?

I usually curse MS word and then run the following Wscript.

// replace with path to a file that needs cleaning
PATH = "test.html"

var go=WScript.CreateObject("Scripting.FileSystemObject");
var content=go.GetFile(PATH).OpenAsTextStream().ReadAll();
var out=go.CreateTextFile("clean-"+PATH, true);

// symbols


Twitter Bootstrap button click to toggle expand/collapse text section above button

Based on the doc

<div class="row">
    <div class="span4 collapse-group">
        <p class="collapse">Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p>
        <p><a class="btn" href="#">View details &raquo;</a></p>
$('.row .btn').on('click', function(e) {
    var $this = $(this);
    var $collapse = $this.closest('.collapse-group').find('.collapse');

Working demo.

What does "implements" do on a class?

Interfaces are implemented through classes. They are purely abstract classes, if you will.

In PHP when a class implements from an interface, the methods defined in that interface are to be strictly followed. When a class inherits from a parent class, method parameters may be altered. That is not the case for interfaces:

interface ImplementMeStrictly {
   public function foo($a, $b);

class Obedient implements ImplementMeStrictly {
   public function foo($a, $b, $c) 

will cause an error, because the interface wasn't implemented as defined. Whereas:

class InheritMeLoosely {
   public function foo($a)

class IDoWhateverWithFoo extends InheritMeLoosely {
   public function foo()

Is allowed.

Removing duplicates from a list of lists

k=[[1, 2], [4], [5, 6, 2], [1, 2], [3], [5, 2], [3], [8], [9]]
kl.extend(x for x in k if x not in kl)

which prints,

[[1, 2], [4], [5, 6, 2], [3], [5, 2], [8], [9]]

how to set start value as "0" in chartjs?

For Chart.js 2.*, the option for the scale to begin at zero is listed under the configuration options of the linear scale. This is used for numerical data, which should most probably be the case for your y-axis. So, you need to use this:

options: {
    scales: {
        yAxes: [{
            ticks: {
                beginAtZero: true

A sample line chart is also available here where the option is used for the y-axis. If your numerical data is on the x-axis, use xAxes instead of yAxes. Note that an array (and plural) is used for yAxes (or xAxes), because you may as well have multiple axes.

Adding form action in html in laravel

Form Post Action :

<form method="post" action="{{url('login')}}" accept-charset="UTF-8">

Change your Route : In Routes -> Web.php


Finding modified date of a file/folder

To get the modified date on a single file try:

$lastModifiedDate = (Get-Item "C:\foo.tmp").LastWriteTime

To compare with another:

$dateA= $lastModifiedDate 
$dateB= (Get-Item "C:\other.tmp").LastWriteTime

if ($dateA -ge $dateB) {
  Write-Host("C:\foo.tmp was modified at the same time or after C:\other.tmp")
} else {
  Write-Host("C:\foo.tmp was modified before C:\other.tmp")

Detecting when Iframe content has loaded (Cross browser)

to detect when the iframe has loaded and its document is ready?

It's ideal if you can get the iframe to tell you itself from a script inside the frame. For example it could call a parent function directly to tell it it's ready. Care is always required with cross-frame code execution as things can happen in an order you don't expect. Another alternative is to set ‘var isready= true;’ in its own scope, and have the parent script sniff for ‘contentWindow.isready’ (and add the onload handler if not).

If for some reason it's not practical to have the iframe document co-operate, you've got the traditional load-race problem, namely that even if the elements are right next to each other:

<img id="x" ... />
<script type="text/javascript">
    document.getElementById('x').onload= function() {

there is no guarantee that the item won't already have loaded by the time the script executes.

The ways out of load-races are:

  1. on IE, you can use the ‘readyState’ property to see if something's already loaded;

  2. if having the item available only with JavaScript enabled is acceptable, you can create it dynamically, setting the ‘onload’ event function before setting source and appending to the page. In this case it cannot be loaded before the callback is set;

  3. the old-school way of including it in the markup:

    <img onload="callback(this)" ... />

Inline ‘onsomething’ handlers in HTML are almost always the wrong thing and to be avoided, but in this case sometimes it's the least bad option.

Print text in Oracle SQL Developer SQL Worksheet window

You could set echo to on:

set echo on
REM Querying table
select * from dual;

In SQLDeveloper, hit F5 to run as a script.

How to activate an Anaconda environment

If this happens you would need to set the PATH for your environment (so that it gets the right Python from the environment and Scripts\ on Windows).

Imagine you have created an environment called py33 by using:

conda create -n py33 python=3.3 anaconda

Here the folders are created by default in Anaconda\envs, so you need to set the PATH as:

set PATH=C:\Anaconda\envs\py33\Scripts;C:\Anaconda\envs\py33;%PATH%

Now it should work in the command window:

activate py33

The line above is the Windows equivalent to the code that normally appears in the tutorials for Mac and Linux:

$ source activate py33

More info:!topic/anaconda/8T8i11gO39U

Does `anaconda` create a separate PYTHONPATH variable for each new environment?

SOAP-ERROR: Parsing WSDL: Couldn't load from - but works on WAMP

Try enabling openssl extension in your php.ini if it is disabled. This way I could access the web service without need of any extra arguments, i.e.,

$client = new SoapClient(url);

Show/hide image with JavaScript


<img id="theImage" src="yourImage.png">
<a id="showImage">Show image</a>


document.getElementById("showImage").onclick = function() {
    document.getElementById("theImage").style.display = "block";


#theImage { display:none; }

Moving from JDK 1.7 to JDK 1.8 on Ubuntu

Add the repository and update apt-get:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update

Install Java8 and set it as default:

sudo apt-get install oracle-java8-set-default

Check version:

java -version

pandas python how to count the number of records or rows in a dataframe

Regards to your question... counting one Field? I decided to make it a question, but I hope it helps...

Say I have the following DataFrame

import numpy as np
import pandas as pd

df = pd.DataFrame(np.random.normal(0, 1, (5, 2)), columns=["A", "B"])

You could count a single column by


both evaluate to 5.

The cool thing (or one of many w.r.t. pandas) is that if you have NA values, count takes that into consideration.

So if I did

df['A'][1::2] = np.NAN

The result would be

 A    3
 B    5

Twitter-Bootstrap-2 logo image on top of navbar

You have to also add the "navbar-brand" class to your image a container, also you have to include it inside the .navbar-inner container, like so:

 <div class="navbar navbar-fixed-top">
   <div class="navbar-inner">
     <div class="container">
        <a class="navbar-brand" href="index.html"> <img src="images/57x57x300.jpg"></a>

How can I get the count of milliseconds since midnight for the current?

You can use java.util.Calendar class to get time in milliseconds. Example:

Calendar cal = Calendar.getInstance();
int milliSec = cal.get(Calendar.MILLISECOND);
// print milliSec

java.util.Date date = cal.getTime();
System.out.println("Output: " +  new SimpleDateFormat("yyyy/MM/dd-HH:mm:ss:SSS").format(date));

How to find all the subclasses of a class given its name?

If you just want direct subclasses then .__subclasses__() works fine. If you want all subclasses, subclasses of subclasses, and so on, you'll need a function to do that for you.

Here's a simple, readable function that recursively finds all subclasses of a given class:

def get_all_subclasses(cls):
    all_subclasses = []

    for subclass in cls.__subclasses__():

    return all_subclasses

Wireshark vs Firebug vs Fiddler - pros and cons?

The benefit of WireShark is that it could possibly show you errors in levels below the HTTP protocol. Fiddler will show you errors in the HTTP protocol.

If you think the problem is somewhere in the HTTP request issued by the browser, or you are just looking for more information in regards to what the server is responding with, or how long it is taking to respond, Fiddler should do.

If you suspect something may be wrong in the TCP/IP protocol used by your browser and the server (or in other layers below that), go with WireShark.

Webdriver findElements By xpath

Instead of




Can an html element have multiple ids?

No you cannot have multiple ids for a single tag, but I have seen a tag with a name attribute and an id attribute which are treated the same by some applications.

How do I ignore files in Subversion?

Also, if you use Tortoise SVN you can do this:

  1. In context menu select "TortoiseSVN", then "Properties"
  2. In appeared window click "New", then "Advanced"
  3. In appeared window opposite to "Property name" select or type "svn:ignore", opposite to "Property value" type desired file name or folder name or file mask (in my case it was "*/target"), click "Apply property recursively"
  4. Ok. Ok.
  5. Commit

Javascript : get <img> src and set as variable?

in this situation, you would grab the element by its id using getElementById and then just use .src

var youtubeimgsrc = document.getElementById("youtubeimg").src;

Invalid length for a Base-64 char array

I'm not Reputable enough to upvote or comment yet, but LukeH's answer was spot on for me.

As AES encryption is the standard to use now, it produces a base64 string (at least all the encrypt/decrypt implementations I've seen). This string has a length in multiples of 4 (string.length % 4 = 0)

The strings I was getting contained + and = on the beginning or end, and when you just concatenate that into a URL's querystring, it will look right (for instance, in an email you generate), but when the the link is followed and the .NET page recieves it and puts it into this.Page.Request.QueryString, those special characters will be gone and your string length will not be in a multiple of 4.

As the are special characters at the FRONT of the string (ex: +), as well as = at the end, you can't just add some = to make up the difference as you are altering the cypher text in a way that doesn't match what was actually in the original querystring.

So, wrapping the cypher text with HttpUtility.URLEncode (not HtmlEncode) transforms the non-alphanumeric characters in a way that ensures .NET parses them back into their original state when it is intepreted into the querystring collection.

The good thing is, we only need to do the URLEncode when generating the querystring for the URL. On the incoming side, it's automatically translated back into the original string value.

Here's some example code

string cryptostring = MyAESEncrypt(MySecretString);
string URL = WebFunctions.ToAbsoluteUrl("~/ResetPassword.aspx?RPC=" + HttpUtility.UrlEncode(cryptostring));

presenting ViewController with NavigationViewController swift

My navigation bar was not showing, so I have used the following method in Swift 2 iOS 9

let viewController = self.storyboard?.instantiateViewControllerWithIdentifier("Dashboard") as! Dashboard

// Creating a navigation controller with viewController at the root of the navigation stack.
let navController = UINavigationController(rootViewController: viewController)
self.presentViewController(navController, animated:true, completion: nil)

Why is Git better than Subversion?

Why I think Subversion is better than Git (at least for the projects I work on), mainly due to its usability, and simpler workflow:

Git merge is not possible because I have unmerged files

I repeatedly had the same challenge sometime ago. This problem occurs mostly when you are trying to pull from the remote repository and you have some files on your local instance conflicting with the remote version, if you are using git from an IDE such as IntelliJ, you will be prompted and allowed to make a choice if you want to retain your own changes or you prefer the changes in the remote version to overwrite yours'. If you don't make any choice then you fall into this conflict. all you need to do is run:

git merge --abort # The unresolved conflict will be cleared off

And you can continue what you were doing before the break.

How to convert <font size="10"> to px?

Using the data points from the accepted answer you can use polynomial interpolation to obtain a formula.

WolframAlpha Input: interpolating polynomial {{1,.63},{2,.82}, {3,1}, {4,1.13}, {5,1.5}, {6, 2}, {7,3}}

Formula: 0.00223611x^6 - 0.0530417x^5 + 0.496319x^4 - 2.30479x^3 + 5.51644x^2 - 6.16717x + 3.14

And use in Groovy code:

import java.math.*
def convert = {x -> (0.00223611*x**6 - 0.053042*x**5 + 0.49632*x**4 - 2.30479*x**3 + 5.5164*x**2 - 6.167*x + 3.14).setScale(2, RoundingMode.HALF_UP) }
(1..7).each { i -> println(convert(i)) }

Gradle store on local file system

On my windows machine with "Buildship 2.0.2" plugin installed in eclipse, dependencies are stored :


What is the T-SQL syntax to connect to another SQL Server?

Try PowerShell Type like:

$cn = new-object"Data Source=server1;Initial Catalog=db1;User ID=user1;Password=password1");
$cmd = new-object"exec Proc1", $cn);
$cmd.CommandTimeout = 0

numpy matrix vector multiplication

Simplest solution

Use or See the documentation here.

>>> a = np.array([[ 5, 1 ,3], 
                  [ 1, 1 ,1], 
                  [ 1, 2 ,1]])
>>> b = np.array([1, 2, 3])
>>> print
array([16, 6, 8])

This occurs because numpy arrays are not matrices, and the standard operations *, +, -, / work element-wise on arrays. Instead, you could try using numpy.matrix, and * will be treated like matrix multiplication.

Other Solutions

Also know there are other options:

  • As noted below, if using python3.5+ the @ operator works as you'd expect:

    >>> print(a @ b)
    array([16, 6, 8])
  • If you want overkill, you can use numpy.einsum. The documentation will give you a flavor for how it works, but honestly, I didn't fully understand how to use it until reading this answer and just playing around with it on my own.

    >>> np.einsum('ji,i->j', a, b)
    array([16, 6, 8])
  • As of mid 2016 (numpy 1.10.1), you can try the experimental numpy.matmul, which works like with two major exceptions: no scalar multiplication but it works with stacks of matrices.

    >>> np.matmul(a, b)
    array([16, 6, 8])
  • numpy.inner functions the same way as for matrix-vector multiplication but behaves differently for matrix-matrix and tensor multiplication (see Wikipedia regarding the differences between the inner product and dot product in general or see this SO answer regarding numpy's implementations).

    >>> np.inner(a, b)
    array([16, 6, 8])
    # Beware using for matrix-matrix multiplication though!
    >>> b = a.T
    >>>, b)
    array([[35,  9, 10],
           [ 9,  3,  4],
           [10,  4,  6]])
    >>> np.inner(a, b) 
    array([[29, 12, 19],
           [ 7,  4,  5],
           [ 8,  5,  6]])

Rarer options for edge cases

  • If you have tensors (arrays of dimension greater than or equal to one), you can use numpy.tensordot with the optional argument axes=1:

    >>> np.tensordot(a, b, axes=1)
    array([16,  6,  8])
  • Don't use numpy.vdot if you have a matrix of complex numbers, as the matrix will be flattened to a 1D array, then it will try to find the complex conjugate dot product between your flattened matrix and vector (which will fail due to a size mismatch n*m vs n).

Stop MySQL service windows

On windows 10

If you wanna close it open command prompt with work with admin. Write NET STOP MySQL80. Its done. If you wanna open again so you must write NET START MySQL80

If you do not want it to be turned on automatically when not in use, it automatically runs when the computer is turned on and consumes some ram.

Open services.msc find Mysql80 , look at properties and turn start type manuel or otomaticly again as you wish.


You can find stats-dot-com - personally I think their are better than opta. ESPN seems don't provide data in full and do not provide live data feeds (unfortunatelly).

We've been seeking for official data feed providing for our fantasy games ( and still staying with stats-com mainly (used opta, datafactory as well)

Mixing C# & VB In The Same Project

At the risk of echoing every other answer, no, you cannot mix them in the same project.

That aside, if you just finished converting VB to C#, why would you write new code in VB?

How to show the text on a ImageButton?

you can use a regular Button and the android:drawableTop attribute (or left, right, bottom) instead.

CSS: How to align vertically a "label" and "input" inside a "div"?

This works cross-browser, provides more accessibility and comes with less markup. ditch the div. Wrap the label

     display: block; 
     height: 35px; 
     line-height: 35px; 
     border: 1px solid #000; 

input{margin-top:15px; height:20px}

<label for="name">Name: <input type="text" id="name" /></label>

include antiforgerytoken in ajax post ASP.NET MVC

You have incorrectly specified the contentType to application/json.

Here's an example of how this might work.


public class HomeController : Controller
    public ActionResult Index()
        return View();

    public ActionResult Index(string someValue)
        return Json(new { someValue = someValue });


@using (Html.BeginForm(null, null, FormMethod.Post, new { id = "__AjaxAntiForgeryForm" }))

<div id="myDiv" data-url="@Url.Action("Index", "Home")">
    Click me to send an AJAX request to a controller action
    decorated with the [ValidateAntiForgeryToken] attribute

<script type="text/javascript">
    $('#myDiv').submit(function () {
        var form = $('#__AjaxAntiForgeryForm');
        var token = $('input[name="__RequestVerificationToken"]', form).val();
            url: $(this).data('url'),
            type: 'POST',
            data: { 
                __RequestVerificationToken: token, 
                someValue: 'some value' 
            success: function (result) {
        return false;

HTTP post XML data in C#

In General:

An example of an easy way to post XML data and get the response (as a string) would be the following function:

public string postXMLData(string destinationUrl, string requestXml)
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destinationUrl);
    byte[] bytes;
    bytes = System.Text.Encoding.ASCII.GetBytes(requestXml);
    request.ContentType = "text/xml; encoding='utf-8'";
    request.ContentLength = bytes.Length;
    request.Method = "POST";
    Stream requestStream = request.GetRequestStream();
    requestStream.Write(bytes, 0, bytes.Length);
    HttpWebResponse response;
    response = (HttpWebResponse)request.GetResponse();
    if (response.StatusCode == HttpStatusCode.OK)
        Stream responseStream = response.GetResponseStream();
        string responseStr = new StreamReader(responseStream).ReadToEnd();
        return responseStr;
    return null;

In your specific situation:

Instead of:

request.ContentType = "application/x-www-form-urlencoded";


request.ContentType = "text/xml; encoding='utf-8'";

Also, remove:

string postData = "XMLData=" + Sendingxml;

And replace:

byte[] byteArray = Encoding.UTF8.GetBytes(postData);


byte[] byteArray = Encoding.UTF8.GetBytes(Sendingxml.ToString());

How to set Java environment path in Ubuntu

Ubuntu installs openjdk6 to /usr/lib/jvm/java-6-openjdk path. So you will have the bin in /usr/lib/jvm/java-6-openjdk/bin. Usually the classpath is automatically set for the java & related executables.

Proper use of errors

Simple solution to emit and show message by Exception.

try {
  throw new TypeError("Error message");
catch (e){
  console.log((<Error>e).message);//conversion to Error type


Above is not a solution if we don't know what kind of error can be emitted from the block. In such cases type guards should be used and proper handling for proper error should be done - take a look on @Moriarty answer.

How to get MD5 sum of a string using python?

Try This 
import hashlib
user = input("Enter text here ")
h = hashlib.md5(user.encode())
h2 = h.hexdigest()

How can I do an OrderBy with a dynamic string parameter?

The simplest & the best solution:

mylist.OrderBy(s => s.GetType().GetProperty("PropertyName").GetValue(s));

#1146 - Table 'phpmyadmin.pma_recent' doesn't exist

You have to run the create_tables.sql inside the examples/ folder on phpMyAdmin to create the tables needed for the advanced features. That or disable those features by commenting them on the config file.

Javascript ES6/ES5 find in array and change

An other approach is to use splice.

The splice() method changes the contents of an array by removing or replacing existing elements and/or adding new elements in place.

N.B : In case you're working with reactive frameworks, it will update the "view", your array "knowing" you've updated it.

Answer :

var item = {...}
var items = [{id:2}, {id:2}, {id:2}];

let foundIndex = items.findIndex(element => ===
items.splice(foundIndex, 1, item)

And in case you want to only change a value of an item, you can use find function :

// Retrieve item and assign ref to updatedItem
let updatedItem = items.find((element) => { return === })

// Modify object property
updatedItem.aProp = ds.aProp

How can I turn a DataTable to a CSV?

The following shorter version opens fine in Excel, maybe your issue was the trailing comma

.net = 3.5

StringBuilder sb = new StringBuilder(); 

string[] columnNames = dt.Columns.Cast<DataColumn>().
                                  Select(column => column.ColumnName).
sb.AppendLine(string.Join(",", columnNames));

foreach (DataRow row in dt.Rows)
    string[] fields = row.ItemArray.Select(field => field.ToString()).
    sb.AppendLine(string.Join(",", fields));

File.WriteAllText("test.csv", sb.ToString());

.net >= 4.0

And as Tim pointed out, if you are on .net>=4, you can make it even shorter:

StringBuilder sb = new StringBuilder(); 

IEnumerable<string> columnNames = dt.Columns.Cast<DataColumn>().
                                  Select(column => column.ColumnName);
sb.AppendLine(string.Join(",", columnNames));

foreach (DataRow row in dt.Rows)
    IEnumerable<string> fields = row.ItemArray.Select(field => field.ToString());
    sb.AppendLine(string.Join(",", fields));

File.WriteAllText("test.csv", sb.ToString());

As suggested by Christian, if you want to handle special characters escaping in fields, replace the loop block by:

foreach (DataRow row in dt.Rows)
    IEnumerable<string> fields = row.ItemArray.Select(field => 
      string.Concat("\"", field.ToString().Replace("\"", "\"\""), "\""));
    sb.AppendLine(string.Join(",", fields));

And last suggestion, you could write the csv content line by line instead of as a whole document, to avoid having a big document in memory.

How can I hide an HTML table row <tr> so that it takes up no space?


<input type="checkbox" id="attraction" checked="checked" onchange="updateMap()">poi.attraction</input>


function updateMap() {
     map.setOptions({'styles': getStyles() });

function getStyles() {
    var styles = [];
    for (var i=0; i < types.length; i++) {
      var style = {};
      var type = types[i];
      var enabled = document.getElementById(type).checked;
      style['featureType'] = 'poi.' + type;
      style['elementType'] = 'labels';
      style['stylers'] = [{'visibility' : (enabled ? 'on' : 'off') }];
    return styles;

Phone number validation Android

Here is how you can do it succinctly in Kotlin:

fun String.isPhoneNumber() =
            length in 4..10 && all { it.isDigit() }

What is the difference between 'classic' and 'integrated' pipeline mode in IIS7?

Classic mode (the only mode in IIS6 and below) is a mode where IIS only works with ISAPI extensions and ISAPI filters directly. In fact, in this mode, ASP.NET is just an ISAPI extension (aspnet_isapi.dll) and an ISAPI filter (aspnet_filter.dll). IIS just treats ASP.NET as an external plugin implemented in ISAPI and works with it like a black box (and only when it's needs to give out the request to ASP.NET). In this mode, ASP.NET is not much different from PHP or other technologies for IIS.

Integrated mode, on the other hand, is a new mode in IIS7 where IIS pipeline is tightly integrated (i.e. is just the same) as ASP.NET request pipeline. ASP.NET can see every request it wants to and manipulate things along the way. ASP.NET is no longer treated as an external plugin. It's completely blended and integrated in IIS. In this mode, ASP.NET HttpModules basically have nearly as much power as an ISAPI filter would have had and ASP.NET HttpHandlers can have nearly equivalent capability as an ISAPI extension could have. In this mode, ASP.NET is basically a part of IIS.

How to check if an array element exists?

You can also use array_keys for number of occurrences

$i=count(array_keys($array, 6));
 echo "Element exists in Array";

Allowing the "Enter" key to press the submit button, as opposed to only using MouseClick

In the ActionListener Class you can simply add

public void actionPerformed(ActionEvent event) {
    if (event.getSource()==textField){
    else if (event.getSource()==textButton) {
        //do something

Swipe to Delete and the "More" button (like in Mail app on iOS 7)

As of iOS 11 this is publicly available in UITableViewDelegate. Here's some sample code:

- (UISwipeActionsConfiguration *)tableView:(UITableView *)tableView trailingSwipeActionsConfigurationForRowAtIndexPath:(NSIndexPath *)indexPath {
    UIContextualAction *delete = [UIContextualAction contextualActionWithStyle:UIContextualActionStyleDestructive
                                                                       handler:^(UIContextualAction * _Nonnull action, __kindof UIView * _Nonnull sourceView, void (^ _Nonnull completionHandler)(BOOL)) {
                                                                           NSLog(@"index path of delete: %@", indexPath);

    UIContextualAction *rename = [UIContextualAction contextualActionWithStyle:UIContextualActionStyleNormal
                                                                       handler:^(UIContextualAction * _Nonnull action, __kindof UIView * _Nonnull sourceView, void (^ _Nonnull completionHandler)(BOOL)) {
                                                                           NSLog(@"index path of rename: %@", indexPath);

    UISwipeActionsConfiguration *swipeActionConfig = [UISwipeActionsConfiguration configurationWithActions:@[rename, delete]];
    swipeActionConfig.performsFirstActionWithFullSwipe = NO;

    return swipeActionConfig;

Also available:

- (UISwipeActionsConfiguration *)tableView:(UITableView *)tableView leadingSwipeActionsConfigurationForRowAtIndexPath:(NSIndexPath *)indexPath;


How to put a delay on AngularJS instant search?

Just for users redirected here:

As introduced in Angular 1.3 you can use ng-model-options attribute:

       placeholder="live search..." 
       ng-model-options="{ debounce: 250 }"

LINQ's Distinct() on a particular property

Please give a try with below code.

var Item = GetAll().GroupBy(x => x .Id).ToList();

ASP.Net which user account running Web Service on IIS 7?

Server 2008

Start Task Manager Find w3wp.exe process (description IIS Worker Process) Check User Name column to find who you're IIS process is running as.

In the IIS GUI you can configure your application pool to run as a specific user: Application Pool default Advanced Settings Identity

Here's the info from Microsoft on setting up Application Pool Identites:

(unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

it worked for me by neutralizing the '\' by f = open('F:\\file.csv')

Get month and year from a datetime in SQL Server 2005

( Month(Created) + ',' + Year(Created) ) AS Date

Split text with '\r\n'

This worked for me.

string stringSeparators = "\r\n";
string text = sr.ReadToEnd();
string lines = text.Replace(stringSeparators, "");
lines = lines.Replace("\\r\\n", "\r\n");

The first replace replaces the \r\n from the text file's new lines, and the second replaces the actual \r\n text that is converted to \\r\\n when the files is read. (When the file is read \ becomes \\).

null vs empty string in Oracle

This is because Oracle internally changes empty string to NULL values. Oracle simply won't let insert an empty string.

On the other hand, SQL Server would let you do what you are trying to achieve.

There are 2 workarounds here:

  1. Use another column that states whether the 'description' field is valid or not
  2. Use some dummy value for the 'description' field where you want it to store empty string. (i.e. set the field to be 'stackoverflowrocks' assuming your real data will never encounter such a description value)

Both are, of course, stupid workarounds :)

How to reduce the space between <p> tags?

Setting both margin-bottom and margin-top to 0em will remove a space between paragraphs:

<style type="text/css">
p {margin-bottom: 0em; margin-top: 0em;}

How to Copy Text to Clip Board in Android?

Kotlin helper method to attach click to copy Texts on a TextView

Put this method somewhere in Util class. This method attach click listener on textview to Copy Content of textView to a clipText on click of that textView

 * Param:  cliplabel, textview, context
fun attachClickToCopyText(textView: TextView?, clipLabel: String, context: Context?) {
    if (textView != null && null != context) {
        textView.setOnClickListener {
            val clipboard = context.getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
            val clip = ClipData.newPlainText(clipLabel, textView!!.text)
            clipboard.primaryClip = clip
                    "Copied $clipLabel", Snackbar.LENGTH_LONG).show()


Relative imports - ModuleNotFoundError: No module named x

As was stated in the comments to the original post, this seemed to be an issue with the python interpreter I was using for whatever reason, and not something wrong with the python scripts. I switched over from the WinPython bundle to the official python 3.6 from and it worked just fine. thanks for the help everyone :)

Passing data through intent using Serializable

Create your custom object and implement Serializable. Next, you can use intent.putExtra("", <your-serializable-object>).

In the second activity, you read it using getIntent().getSerializableExtra("")

Otherwise, follow this and this page.

Why use #ifndef CLASS_H and #define CLASS_H in .h file but not in .cpp?

main.cpp doesn't have to know what is in class.cpp. It just has to know the declarations of the functions/classes that it goes to use, and these declarations are in class.h.

The linker links between the places where the functions/classes declared in class.h are used and their implementations in class.cpp

How to return value from function which has Observable subscription inside?

While the previous answers may work in a fashion, I think that using BehaviorSubject is the correct way if you want to continue using observables.

        (data:any) => {

In the Service:

let myBehaviorSubject = new BehaviorSubjet(value);

In component.ts:

this.myService.myBehaviorSubject.subscribe(data => this.myData = data)

I hope this helps!

Default visibility for C# classes and members (fields, methods, etc.)?

By default, the access modifier for a class is internal. That means to say, a class is accessible within the same assembly. But if we want the class to be accessed from other assemblies then it has to be made public.

Spring MVC How take the parameter value of a GET HTTP Request in my controller method?

As explained in the documentation, by using an @RequestParam annotation:

public @ResponseBody String byParameter(@RequestParam("foo") String foo) {
    return "Mapped by path + method + presence of query parameter! (MappingController) - foo = "
           + foo;

How to add header row to a pandas DataFrame

You can use names directly in the read_csv

names : array-like, default None List of column names to use. If file contains no header row, then you should explicitly pass header=None

Cov = pd.read_csv("path/to/file.txt", 
                  names=["Sequence", "Start", "End", "Coverage"])

How to define relative paths in Visual Studio Project?

Instead of using relative paths, you could also use the predefined macros of VS to achieve this.

$(ProjectDir) points to the directory of your .vcproj file, $(SolutionDir) is the directory of the .sln file.

You get a list of available macros when opening a project, go to
Properties → Configuration Properties → C/C++ → General
and hit the three dots:

project properties

In the upcoming dialog, hit Macros to see the macros that are predefined by the Studio (consult MSDN for their meaning):

additional include directories

You can use the Macros by typing $(MACRO_NAME) (note the $ and the round brackets).

Push eclipse project to GitHub with EGit

The key lies in when you create the project in eclipse.

First step, you create the Java project in eclipse. Right click on the project and choose Team > Share>Git.

In the Configure Git Repository dialog, ensure that you select the option to create the Repository in the parent folder of the project.. enter image description here Then you can push to github.

N.B: Eclipse will give you a warning about putting git repositories in your workspace. So when you create your project, set your project directory outside the default workspace.

Delete dynamically-generated table row using jQuery

When cloning, by default it will not clone the events. The added rows do not have an event handler attached to them. If you call clone(true) then it should handle them as well.

How can I execute a PHP function in a form action?

require_once ( 'username.php' );

if (isset($_POST['textfield'])) {
    echo username();

echo '
<form name="form1" method="post" action="">
      <input type="text" name="textfield" id="textfield">
      <input type="submit" name="button" id="button" value="Submit">

You need to run the function in the page the form is sent to.

How to clear Facebook Sharer cache?

I thing these two links have a wide discussion on your problem related stuff. fb:ref clear cashes by calling


like this


You can study the related stuff from here fb:ref. I hope it will work for you

How to initialize a variable of date type in java?

To initialize to current date, you could do something like:

Date firstDate = new Date();

To get it from String, you could use SimpleDateFormat like:

String dateInString = "10-Jan-2016";
SimpleDateFormat formatter = new SimpleDateFormat("dd-MMM-yyyy");
try {
    Date date = formatter.parse(dateInString);
} catch (ParseException e) {
    //handle exception if date is not in "dd-MMM-yyyy" format

HttpContext.Current.Request.Url.Host what it returns?

The Host property will return the domain name you used when accessing the site. So, in your development environment, since you're requesting


It's returning localhost. You can break apart your URL like so:

Protocol: http
Host: localhost
Port: 950
PathAndQuery: /m/pages/SearchResults.aspx?search=knight&filter=kitchen

How to combine 2 plots (ggplot) into one plot?

Dummy data (you should supply this for us)

visual1 = data.frame(ISSUE_DATE=runif(100,2006,2008),COUNTED=runif(100,0,50))
visual2 = data.frame(ISSUE_DATE=runif(100,2006,2008),COUNTED=runif(100,0,50))


visuals = rbind(visual1,visual2)
visuals$vis=c(rep("visual1",100),rep("visual2",100)) # 100 points of each flavour

Now do:

 ggplot(visuals, aes(ISSUE_DATE,COUNTED,group=vis,col=vis)) + 
   geom_point() + geom_smooth()

and adjust colours etc to taste.

enter image description here

converting a javascript string to a html object

In addition to Gaby aka's method, we can find elements inside htmlObject in this way -


Fiddle is available here -

Round a divided number in Bash

I think this should be enough.

$ echo "3/2" | bc 

How to import and export components using React + ES6 + webpack?

I Hope this is Helpfull

Step 1: App.js is (main module) import the Login Module

import React, { Component } from 'react';
import './App.css';
import Login from './login/login';

class App extends Component {
  render() {
    return (
      <Login />

export default App;

Step 2: Create Login Folder and create login.js file and customize your needs it automatically render to App.js Example Login.js

import React, { Component } from 'react';
import '../login/login.css';

class Login extends Component {
  render() {
    return (
      <div className="App">
        <header className="App-header">
          <h1 className="App-title">Welcome to React</h1>
        <p className="App-intro">
          To get started, edit <code>src/App.js</code> and save to reload.

export default Login;

Server Discovery And Monitoring engine is deprecated

It is important to run your mongod command and keep the server running. If not, you will still be seeing this error.

I attach you my code:

const mongodb = require('mongodb')
const MongoClient = mongodb.MongoClient

const connectionURL = 'mongodb://'
const databaseName = 'task-manager'

MongoClient.connect(connectionURL, {useNewUrlParser: true, useUnifiedTopology: true}, (error, client) => {
    if(error) {
        return console.log('Error connecting to the server.')

    console.log('Succesfully connected.')

What's the difference between Instant and LocalDateTime?

Table of all date-time types in Java, both modern and legacy


Instant and LocalDateTime are two entirely different animals: One represents a moment, the other does not.

  • Instant represents a moment, a specific point in the timeline.
  • LocalDateTime represents a date and a time-of-day. But lacking a time zone or offset-from-UTC, this class cannot represent a moment. It represents potential moments along a range of about 26 to 27 hours, the range of all time zones around the globe. A LocalDateTime value is inherently ambiguous.

Incorrect Presumption

LocalDateTime is rather date/clock representation including time-zones for humans.

Your statement is incorrect: A LocalDateTime has no time zone. Having no time zone is the entire point of that class.

To quote that class’ doc:

This class does not store or represent a time-zone. Instead, it is a description of the date, as used for birthdays, combined with the local time as seen on a wall clock. It cannot represent an instant on the time-line without additional information such as an offset or time-zone.

So Local… means “not zoned, no offset”.


enter image description here

An Instant is a moment on the timeline in UTC, a count of nanoseconds since the epoch of the first moment of 1970 UTC (basically, see class doc for nitty-gritty details). Since most of your business logic, data storage, and data exchange should be in UTC, this is a handy class to be used often.

Instant instant = ;  // Capture the current moment in UTC.


enter image description here

The class OffsetDateTime class represents a moment as a date and time with a context of some number of hours-minutes-seconds ahead of, or behind, UTC. The amount of offset, the number of hours-minutes-seconds, is represented by the ZoneOffset class.

If the number of hours-minutes-seconds is zero, an OffsetDateTime represents a moment in UTC the same as an Instant.


enter image description here

The ZoneOffset class represents an offset-from-UTC, a number of hours-minutes-seconds ahead of UTC or behind UTC.

A ZoneOffset is merely a number of hours-minutes-seconds, nothing more. A zone is much more, having a name and a history of changes to offset. So using a zone is always preferable to using a mere offset.


enter image description here

A time zone is represented by the ZoneId class.

A new day dawns earlier in Paris than in Montréal, for example. So we need to move the clock’s hands to better reflect noon (when the Sun is directly overhead) for a given region. The further away eastward/westward from the UTC line in west Europe/Africa the larger the offset.

A time zone is a set of rules for handling adjustments and anomalies as practiced by a local community or region. The most common anomaly is the all-too-popular lunacy known as Daylight Saving Time (DST).

A time zone has the history of past rules, present rules, and rules confirmed for the near future.

These rules change more often than you might expect. Be sure to keep your date-time library's rules, usually a copy of the 'tz' database, up to date. Keeping up-to-date is easier than ever now in Java 8 with Oracle releasing a Timezone Updater Tool.

Specify a proper time zone name in the format of Continent/Region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 2-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

Time Zone = Offset + Rules of Adjustments

ZoneId z = ZoneId.of( “Africa/Tunis” ) ; 


enter image description here

Think of ZonedDateTime conceptually as an Instant with an assigned ZoneId.

ZonedDateTime = ( Instant + ZoneId )

To capture the current moment as seen in the wall-clock time used by the people of a particular region (a time zone):

ZonedDateTime zdt = z ) ;  // Pass a `ZoneId` object such as `ZoneId.of( "Europe/Paris" )`. 

Nearly all of your backend, database, business logic, data persistence, data exchange should all be in UTC. But for presentation to users you need to adjust into a time zone expected by the user. This is the purpose of the ZonedDateTime class and the formatter classes used to generate String representations of those date-time values.

ZonedDateTime zdt = instant.atZone( z ) ;
String output = zdt.toString() ;                 // Standard ISO 8601 format.

You can generate text in localized format using DateTimeFormatter.

DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.FULL ).withLocale( Locale.CANADA_FRENCH ) ; 
String outputFormatted = zdt.format( f ) ;

mardi 30 avril 2019 à 23 h 22 min 55 s heure de l’Inde

LocalDate, LocalTime, LocalDateTime

Diagram showing only a calendar for a LocalDate.

Diagram showing only a clock for a LocalTime.

Diagram showing a calendar plus clock for a LocalDateTime.

The "local" date time classes, LocalDateTime, LocalDate, LocalTime, are a different kind of critter. The are not tied to any one locality or time zone. They are not tied to the timeline. They have no real meaning until you apply them to a locality to find a point on the timeline.

The word “Local” in these class names may be counter-intuitive to the uninitiated. The word means any locality, or every locality, but not a particular locality.

So for business apps, the "Local" types are not often used as they represent just the general idea of a possible date or time not a specific moment on the timeline. Business apps tend to care about the exact moment an invoice arrived, a product shipped for transport, an employee was hired, or the taxi left the garage. So business app developers use Instant and ZonedDateTime classes most commonly.

So when would we use LocalDateTime? In three situations:

  • We want to apply a certain date and time-of-day across multiple locations.
  • We are booking appointments.
  • We have an intended yet undetermined time zone.

Notice that none of these three cases involve a single certain specific point on the timeline, none of these are a moment.

One time-of-day, multiple moments

Sometimes we want to represent a certain time-of-day on a certain date, but want to apply that into multiple localities across time zones.

For example, "Christmas starts at midnight on the 25th of December 2015" is a LocalDateTime. Midnight strikes at different moments in Paris than in Montréal, and different again in Seattle and in Auckland.

LocalDate ld = LocalDate.of( 2018 , Month.DECEMBER , 25 ) ;
LocalTime lt = LocalTime.MIN ;   // 00:00:00
LocalDateTime ldt = LocalDateTime.of( ld , lt ) ;  // Christmas morning anywhere. 

Another example, "Acme Company has a policy that lunchtime starts at 12:30 PM at each of its factories worldwide" is a LocalTime. To have real meaning you need to apply it to the timeline to figure the moment of 12:30 at the Stuttgart factory or 12:30 at the Rabat factory or 12:30 at the Sydney factory.

Booking appointments

Another situation to use LocalDateTime is for booking future events (ex: Dentist appointments). These appointments may be far enough out in the future that you risk politicians redefining the time zone. Politicians often give little forewarning, or even no warning at all. If you mean "3 PM next January 23rd" regardless of how the politicians may play with the clock, then you cannot record a moment – that would see 3 PM turn into 2 PM or 4 PM if that region adopted or dropped Daylight Saving Time, for example.

For appointments, store a LocalDateTime and a ZoneId, kept separately. Later, when generating a schedule, on-the-fly determine a moment by calling LocalDateTime::atZone( ZoneId ) to generate a ZonedDateTime object.

ZonedDateTime zdt = ldt.atZone( z ) ;  // Given a date, a time-of-day, and a time zone, determine a moment, a point on the timeline.

If needed, you can adjust to UTC. Extract an Instant from the ZonedDateTime.

Instant instant = zdt.toInstant() ;  // Adjust from some zone to UTC. Same moment, same point on the timeline, different wall-clock time.

Unknown zone

Some people might use LocalDateTime in a situation where the time zone or offset is unknown.

I consider this case inappropriate and unwise. If a zone or offset is intended but undetermined, you have bad data. That would be like storing a price of a product without knowing the intended currency (dollars, pounds, euros, etc.). Not a good idea.

All date-time types

For completeness, here is a table of all the possible date-time types, both modern and legacy in Java, as well as those defined by the SQL standard. This might help to place the Instant & LocalDateTime classes in a larger context.

Table of all date-time types in Java (both modern & legacy) as well as SQL standard.

Notice the odd choices made by the Java team in designing JDBC 4.2. They chose to support all the java.time times… except for the two most commonly used classes: Instant & ZonedDateTime.

But not to worry. We can easily convert back and forth.

Converting Instant.

// Storing
OffsetDateTime odt = instant.atOffset( ZoneOffset.UTC ) ;
myPreparedStatement.setObject( … , odt ) ;

// Retrieving
OffsetDateTime odt = myResultSet.getObject( … , OffsetDateTime.class ) ;
Instant instant = odt.toInstant() ;

Converting ZonedDateTime.

// Storing
OffsetDateTime odt = zdt.toOffsetDateTime() ;
myPreparedStatement.setObject( … , odt ) ;

// Retrieving
OffsetDateTime odt = myResultSet.getObject( … , OffsetDateTime.class ) ;
ZoneId z = ZoneId.of( "Asia/Kolkata" ) ;
ZonedDateTime zdt = odt.atZone( z ) ; 

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.

Where to obtain the java.time classes?

Table of which java.time library to use with which version of Java or Android

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Getting Class type from String

Not sure what you are asking, but... Class.forname, maybe?

How to override !important?

Disclaimer: Avoid !important at all cost.

This is a dirty, dirty hack, but you can override an !important, without an !important, by using an (infinitely looping or very long lasting) animation on the property you're trying to override the importants on.

@keyframes forceYellow {_x000D_
  from {_x000D_
    background-color: yellow;_x000D_
  to {_x000D_
    background-color: yellow;_x000D_
div {_x000D_
  width: 100px;_x000D_
  height: 100px;_x000D_
  margin: 0 auto;_x000D_
  background: red !important;_x000D_
  animation: 1s linear infinite forceYellow;_x000D_

ASP.NET MVC Html.DropDownList SelectedValue

The code in the previous MVC 3 post does not work but it is a good start. I will fix it. I have tested this code and it works in MVC 3 Razor C# This code uses the ViewModel pattern to populate a property that returns a List<SelectListItem>.

The Model class

public class Product
    public string Name { get; set; }
    public decimal Price { get; set; }

The ViewModel class

using System.Web.Mvc;

public class ProductListviewModel
    public List<SelectListItem> Products { get; set; }

The Controller Method

public ViewResult List()
    var productList = new List<SelectListItem>();

    foreach (Product p in Products)
        productList.Add(new SelectListItem
            Value = p.ProductId.ToString(),
            Text = "Product: " + p.Name + " " + p.Price.ToString(),
            // To set the selected item use the following code 
            // Note: you should not set every item to selected
            Selected = true

    ProductListViewModel productListVM = new ProductListViewModeld();

    productListVM.Products = productList;

    return View(productListVM);

The view

@model MvcApp.ViewModels.ProductListViewModel

@using (Html.BeginForm())
    @Html.DropDownList("Products", Model.Products)

The HTML output will be something like

<select id="Products" name="Products">
    <option value="3">Product: Widget 10.00</option>
    <option value="4">Product: Gadget 5.95</option>

depending on how you format the output. I hope this helps. The code does work.

Load local HTML file in a C# WebBrowser

quite late but it's the first hit i found from google

Instead of using the current directory or getting the assembly, just use the Application.ExecutablePath property:

//using System.IO;  
string applicationDirectory = Path.GetDirectoryName(Application.ExecutablePath);
string myFile = Path.Combine(applicationDirectory, "Sample.html");
webMain.Url = new Uri("file:///" + myFile);

Pass form data to another page with php

The best way to accomplish that is to use POST which is a method of Hypertext Transfer Protocol



<form action="site2.php" method="post">
Name: <input type="text" name="name">
Email: <input type="text" name="email">
<input type="submit">




 Hello <?php echo $_POST["name"]; ?>!<br>
 Your mail is <?php echo $_POST["mail"]; ?>.



Hello "name" !

Your email is "[email protected]" .

How to unlock android phone through ADB

If you want to open your phone without touching it here is the way


  1. Make sure you have completed the adb setup in both pc and android
  2. open cmd(Command Prompt)
  3. type adb devices to cheek if your phone is ready or not
  4. If it shows something like
List of devices attached
059c97f4        device

then enter the following command

adb shell input keyevent 26 && adb shell input swipe 600 600 0 0 && adb shell input text <pass> && adb shell input keyevent 66

put your password in <pass> and done. You phone is hopefully opened

WPF Datagrid Get Selected Cell Value

I was to dumb to find the Solution...

For me (VB):

 Dim string= Datagrid.SelectedCells(0).Item(0).ToString

RegEx - Match Numbers of Variable Length

Try this:


The {1,3} means "match between 1 and 3 of the preceding characters".