Programs & Examples On #Ansi sql

ANSI SQL is the American National Standards Institute standardized Structured Query Language. ANSI SQL is the base for the different SQL dialects used by different DBMS vendors. Some vendors have their own name for it (such as Microsoft, which calls it T-SQL) whereas others stick to the name SQL.

T-SQL Cast versus Convert

You should also not use CAST for getting the text of a hash algorithm. CAST(HASHBYTES('...') AS VARCHAR(32)) is not the same as CONVERT(VARCHAR(32), HASHBYTES('...'), 2). Without the last parameter, the result would be the same, but not a readable text. As far as I know, You cannot specify that last parameter in CAST.

Simulating group_concat MySQL function in Microsoft SQL Server 2005?

To concatenate all the project manager names from projects that have multiple project managers write:

SELECT a.project_id,a.project_name,Stuff((SELECT N'/ ' + first_name + ', '+last_name FROM projects_v 
where a.project_id=project_id
 XML PATH(''),TYPE).value('text()[1]','nvarchar(max)'),1,2,N''
) mgr_names
from projects_v a
group by a.project_id,a.project_name

count number of rows in a data frame in R based on group

Here's an example that shows how table(.) (or, more closely matching your desired output, data.frame(table(.)) does what it sounds like you are asking for.

Note also how to share reproducible sample data in a way that others can copy and paste into their session.

Here's the (reproducible) sample data:

mydf <- structure(list(ID = c(110L, 111L, 121L, 131L, 141L), 
                       MONTH.YEAR = c("JAN. 2012", "JAN. 2012", 
                                      "FEB. 2012", "FEB. 2012", 
                                      "MAR. 2012"), 
                       VALUE = c(1000L, 2000L, 3000L, 4000L, 5000L)), 
                  .Names = c("ID", "MONTH.YEAR", "VALUE"), 
                  class = "data.frame", row.names = c(NA, -5L))

# 1 110  JAN. 2012  1000
# 2 111  JAN. 2012  2000
# 3 121  FEB. 2012  3000
# 4 131  FEB. 2012  4000
# 5 141  MAR. 2012  5000

Here's the calculation of the number of rows per group, in two output display formats:

# FEB. 2012 JAN. 2012 MAR. 2012 
#         2         2         1

#        Var1 Freq
# 1 FEB. 2012    2
# 2 JAN. 2012    2
# 3 MAR. 2012    1

Autoplay audio files on an iPad with HTML5

This seems to work:

iPad Sound Test  - Auto Play
<audio id="audio" src="mp3test.mp3" controls="controls" loop="loop">
<script type="text/javascript"> 
    window.onload = function() {
        var audioPlayer = document.getElementById("audio");


See it in action here: (Archived)

As of iOS 4.2 this no-longer works. Sorry.

Background image jumps when address bar hides iOS/Android/Mobile Chrome

The problem can be solved with a media query and some math. Here's a solution for a portait orientation:

@media (max-device-aspect-ratio: 3/4) {
  height: calc(100vw * 1.333 - 9%);
@media (max-device-aspect-ratio: 2/3) {
  height: calc(100vw * 1.5 - 9%);
@media (max-device-aspect-ratio: 10/16) {
  height: calc(100vw * 1.6 - 9%);
@media (max-device-aspect-ratio: 9/16) {
  height: calc(100vw * 1.778 - 9%);

Since vh will change when the url bar dissapears, you need to determine the height another way. Thankfully, the width of the viewport is constant and mobile devices only come in a few different aspect ratios; if you can determine the width and the aspect ratio, a little math will give you the viewport height exactly as vh should work. Here's the process

1) Create a series of media queries for aspect ratios you want to target.

  • use device-aspect-ratio instead of aspect-ratio because the latter will resize when the url bar dissapears

  • I added 'max' to the device-aspect-ratio to target any aspect ratios that happen to follow in between the most popular. THey won't be as precise, but they will be only for a minority of users and will still be pretty close to the proper vh.

  • remember the media query using horizontal/vertical , so for portait you'll need to flip the numbers

2) for each media query multiply whatever percentage of vertical height you want the element to be in vw by the reverse of the aspect ratio.

  • Since you know the width and the ratio of width to height, you just multiply the % you want (100% in your case) by the ratio of height/width.

3) You have to determine the url bar height, and then minus that from the height. I haven't found exact measurements, but I use 9% for mobile devices in landscape and that seems to work fairly well.

This isn't a very elegant solution, but the other options aren't very good either, considering they are:

  • Having your website seem buggy to the user,

  • having improperly sized elements, or

  • Using javascript for some basic styling,

The drawback is some devices may have different url bar heights or aspect ratios than the most popular. However, using this method if only a small number of devices suffer the addition/subtraction of a few pixels, that seems much better to me than everyone having a website resize when swiping.

To make it easier, I also created a SASS mixin:

@mixin vh-fix {
  @media (max-device-aspect-ratio: 3/4) {
    height: calc(100vw * 1.333 - 9%);
  @media (max-device-aspect-ratio: 2/3) {
    height: calc(100vw * 1.5 - 9%);
  @media (max-device-aspect-ratio: 10/16) {
    height: calc(100vw * 1.6 - 9%);
  @media (max-device-aspect-ratio: 9/16) {
    height: calc(100vw * 1.778 - 9%);

How to style a disabled checkbox?

If you're trying to stop someone from updating the checkbox so it appears disabled then just use JQuery


You can then style the checkbox.

C# Threading - How to start and stop a thread

Thread th = new Thread(function1);

void function1(){
//code here

Get the directory from a file path in java (android)

Yes. First, construct a File representing the image path:

File file = new File(a);

If you're starting from a relative path:

file = new File(file.getAbsolutePath());

Then, get the parent:

String dir = file.getParent();

Or, if you want the directory as a File object,

File dirAsFile = file.getParentFile();

Swift Modal View Controller with transparent background

You can do it like this:

In your main view controller:

func showModal() {
    let modalViewController = ModalViewController()
    modalViewController.modalPresentationStyle = .overCurrentContext
    presentViewController(modalViewController, animated: true, completion: nil)

In your modal view controller:

class ModalViewController: UIViewController {
    override func viewDidLoad() {
        view.backgroundColor = UIColor.clearColor()
        view.opaque = false

If you are working with a storyboard:

Just add a Storyboard Segue with Kind set to Present Modally to your modal view controller and on this view controller set the following values:

  • Background = Clear Color
  • Drawing = Uncheck the Opaque checkbox
  • Presentation = Over Current Context

As Crashalot pointed out in his comment: Make sure the segue only uses Default for both Presentation and Transition. Using Current Context for Presentation makes the modal turn black instead of remaining transparent.

Fastest way to count number of occurrences in a Python list

a = ['1', '1', '1', '1', '1', '1', '2', '2', '2', '2', '7', '7', '7', '10', '10']
print a.count("1")

It's probably optimized heavily at the C level.

Edit: I randomly generated a large list.

In [8]: len(a)
Out[8]: 6339347

In [9]: %timeit a.count("1")
10 loops, best of 3: 86.4 ms per loop

Edit edit: This could be done with collections.Counter

a = Counter(your_list)
print a['1']

Using the same list in my last timing example

In [17]: %timeit Counter(a)['1']
1 loops, best of 3: 1.52 s per loop

My timing is simplistic and conditional on many different factors, but it gives you a good clue as to performance.

Here is some profiling

In [24]:"a.count('1')")
         3 function calls in 0.091 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    0.091    0.091 <string>:1(<module>)
        1    0.091    0.091    0.091    0.091 {method 'count' of 'list' objects}

        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Prof
iler' objects}

In [25]:"b = Counter(a); b['1']")
         6339356 function calls in 2.143 seconds

   Ordered by: standard name

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    2.143    2.143 <string>:1(<module>)
        2    0.000    0.000    0.000    0.000
        1    0.000    0.000    0.000    0.000
        1    0.000    0.000    2.143    2.143
        1    1.788    1.788    2.143    2.143
        1    0.000    0.000    0.000    0.000 {getattr}
        1    0.000    0.000    0.000    0.000 {isinstance}
        1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Prof
iler' objects}
  6339347    0.356    0.000    0.356    0.000 {method 'get' of 'dict' objects}

! [rejected] master -> master (fetch first)

Try this git command

git push origin master --force

or short of force -f

git push origin master -f

how to get the host url using javascript from the current page

This should work:


Missing .map resource?

jQuery recently started using source maps.

For example, let's look at the minified jQuery 2.0.3 file's first few lines.

/*! jQuery v2.0.3 | (c) 2005, 2013 jQuery Foundation, Inc. |

Excerpt from Introduction to JavaScript Source Maps:

Have you ever found yourself wishing you could keep your client-side code readable and more importantly debuggable even after you've combined and minified it, without impacting performance? Well now you can through the magic of source maps.

Basically it's a way to map a combined/minified file back to an unbuilt state. When you build for production, along with minifying and combining your JavaScript files, you generate a source map which holds information about your original files. When you query a certain line and column number in your generated JavaScript you can do a lookup in the source map which returns the original location. Developer tools (currently WebKit nightly builds, Google Chrome, or Firefox 23+) can parse the source map automatically and make it appear as though you're running unminified and uncombined files.

emphasis mine

It's incredibly useful, and will only download if the user opens dev tools.


Remove the source mapping line, or do nothing. It isn't really a problem.

Side note: your server should return 404, not 500. It could point to a security problem if this happens in production.

Codesign wants to access key "access" in your keychain, I put in my login password but keeps asking me

Had the same issue. It was fixed after I entered my mac user password and hit Always Allow.

Docker: "no matching manifest for windows/amd64 in the manifest list entries"

Deprecating the ‘latest’ tag

We are deprecating the ‘latest’ tag across all our Windows base images to encourage better container practices. At the beginning of the 2019 calendar year, we will no longer publish the tag ; We’ll yank it from the available tags list.

We strongly encourage you to instead declare the specific container tag you’d like to run in production. The ‘latest’ tag is the opposite of specific; it doesn’t tell the user anything about what version the container actually is apart from the image name. You can read more about version compatibility and selecting the appropriate tag on our container docs .

JavaScript backslash (\) in variables is causing an error

The backslash \ is reserved for use as an escape character in Javascript.

To use a backslash literally you need to use two backslashes


how to print json data in console.log

I used '%j' option in console.log to print JSON objects

console.log("%j", jsonObj);

Get HTML inside iframe using jQuery

$('#iframe').load(function() {
    var src = $('#iframe').contents().find("html").html();

Select DataFrame rows between two dates

I prefer not to alter the df.

An option is to retrieve the index of the start and end dates:

import numpy as np   
import pandas as pd

#Dummy DataFrame
df = pd.DataFrame(np.random.random((30, 3)))
df['date'] = pd.date_range('2017-1-1', periods=30, freq='D')

#Get the index of the start and end dates respectively
start = df[df['date']=='2017-01-07'].index[0]
end = df[df['date']=='2017-01-14'].index[0]

#Show the sliced df (from 2017-01-07 to 2017-01-14)

which results in:

     0   1   2       date
6  0.5 0.8 0.8 2017-01-07
7  0.0 0.7 0.3 2017-01-08
8  0.8 0.9 0.0 2017-01-09
9  0.0 0.2 1.0 2017-01-10
10 0.6 0.1 0.9 2017-01-11
11 0.5 0.3 0.9 2017-01-12
12 0.5 0.4 0.3 2017-01-13
13 0.4 0.9 0.9 2017-01-14

Android Split string

String currentString = "Fruit: they taste good";
String[] separated = currentString.split(":");
separated[0]; // this will contain "Fruit"
separated[1]; // this will contain " they taste good"

You may want to remove the space to the second String:

separated[1] = separated[1].trim();

If you want to split the string with a special character like dot(.) you should use escape character \ before the dot


String currentString = "Fruit: they taste good.very nice actually";
String[] separated = currentString.split("\\.");
separated[0]; // this will contain "Fruit: they taste good"
separated[1]; // this will contain "very nice actually"

There are other ways to do it. For instance, you can use the StringTokenizer class (from java.util):

StringTokenizer tokens = new StringTokenizer(currentString, ":");
String first = tokens.nextToken();// this will contain "Fruit"
String second = tokens.nextToken();// this will contain " they taste good"
// in the case above I assumed the string has always that syntax (foo: bar)
// but you may want to check if there are tokens or not using the hasMoreTokens method

How to split one string into multiple variables in bash shell?

read with IFS are perfect for this:

$ IFS=- read var1 var2 <<< ABCDE-123456
$ echo "$var1"
$ echo "$var2"


Here is how you can read each individual character into array elements:

$ read -a foo <<<"$(echo "ABCDE-123456" | sed 's/./& /g')"

Dump the array:

$ declare -p foo
declare -a foo='([0]="A" [1]="B" [2]="C" [3]="D" [4]="E" [5]="-" [6]="1" [7]="2" [8]="3" [9]="4" [10]="5" [11]="6")'

If there are spaces in the string:

$ IFS=$'\v' read -a foo <<<"$(echo "ABCDE 123456" | sed 's/./&\v/g')"
$ declare -p foo
declare -a foo='([0]="A" [1]="B" [2]="C" [3]="D" [4]="E" [5]=" " [6]="1" [7]="2" [8]="3" [9]="4" [10]="5" [11]="6")'

Splitting a string at every n-th character

You can also split a string at every n-th character and put them each, in each index of a List :

Here I made a list of Strings named Sequence :

List < String > Sequence

Then I'm basically splitting the String "KILOSO" by every 2 words. So 'KI' 'LO' 'SO' would be incorporate in separate index of the List called Sequence.

String S = KILOSO

Sequence = Arrays.asList(S.split("(?<=\G..)"));

So when I'm doing :


It should print :

[KI, LO, SO]

to verify I can write :


it will print :


An item with the same key has already been added

I have had the same error. When i check the code then i found that declare "GET" request in my angular (font-end) side and declare "POST" request in the (back-end) side. Set POST/GET any one in both side. Then solved the error.

What is Java String interning?

Java interning() method basically makes sure that if String object is present in SCP, If yes then it returns that object and if not then creates that objects in SCP and return its references

for eg: String s1=new String("abc");
        String s2="abc";
        String s3="abc";

s1==s2// false, because 1 object of s1 is stored in heap and other in scp(but this objects doesn't have explicit reference) and s2 in scp
s2==s3// true

now if we do intern on s1

//JVM checks if there is any string in the pool with value “abc” is present? Since there is a string object in the pool with value “abc”, its reference is returned.
Notice that we are calling s1 = s1.intern(), so the s1 is now referring to the string pool object having value “abc”.
At this point, all the three string objects are referring to the same object in the string pool. Hence s1==s2 is returning true now.

Why binary_crossentropy and categorical_crossentropy give different performances for the same problem?

I came across an "inverted" issue — I was getting good results with categorical_crossentropy (with 2 classes) and poor with binary_crossentropy. It seems that problem was with wrong activation function. The correct settings were:

  • for binary_crossentropy: sigmoid activation, scalar target
  • for categorical_crossentropy: softmax activation, one-hot encoded target

WPF Datagrid set selected row

I came across this fairly recent (compared to the age of the question) TechNet article that includes some of the best techniques I could find on the topic:

WPF: Programmatically Selecting and Focusing a Row or Cell in a DataGrid

It includes details that should cover most requirements. It is important to remember that if you specify custom templates for the DataGridRow for some rows that these won't have DataGridCells inside and then the normal selection mechanisms of the grid doesn't work.

You'll need to be more specific on what datasource you've given the grid to answer the first part of your question, as the others have stated.

Correlation heatmap

If your data is in a Pandas DataFrame, you can use Seaborn's heatmap function to create your desired plot.

import seaborn as sns

Var_Corr = df.corr()
# plot the heatmap and annotation on it
sns.heatmap(Var_Corr, xticklabels=Var_Corr.columns, yticklabels=Var_Corr.columns, annot=True)

Correlation plot

From the question, it looks like the data is in a NumPy array. If that array has the name numpy_data, before you can use the step above, you would want to put it into a Pandas DataFrame using the following:

import pandas as pd
df = pd.DataFrame(numpy_data)

How do I convert speech to text?

Late to the party, so answering more for future reference.

Advances in the field + Mozilla's mindset and agenda led to these two projects towards that end:

The latter has a 12GB data-set for download. The former allows for training a model with your own audio files to my understanding

How to access the elements of a 2D array?

If you have this :

a = [[1, 1], [2, 1],[3, 1]]

You can easily access this by using :

a[0][1] = 7

Install npm (Node.js Package Manager) on Windows (w/o using Node.js MSI)

TL;DR: Install Chocolatey, Node (and NPM)

Install Chocolatey

NOTE: You might want to copy the exact command from their install page since it might change over time.

  1. Open your standard Windows command line
  2. @powershell -NoProfile -ExecutionPolicy unrestricted -Command "(iex ((new-object net.webclient).DownloadString(''))) >$null 2>&1" && SET PATH="%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"
  3. Restart console
  4. Done!

Install Node (and NPM)

  1. Because Chocolatey installs a directory different from the MSI installation, go to your system configuration and delete your previous node installation (if you have one)
  2. Install Chocolatey as described above
  3. choco install nodejs

    NOTE I used nodejs. I am not even sure what node is, but having had my fair share of troubles with node already being taken by something else in other systems, I thought, nodejs would be the safer bet right away

  4. Restart your console
  5. Beware: node -v works!
    • And npm -v also works! Awesome.

After this, I was able to install firebase-tools without problems (which I was not able to do previously), so something must have gone terribly right! :)

My rather complete story the first time around

"Chocolatey installs in seconds"

If you don't care about sarcasm or lamenting engineers on a Sunday afternoon, skip ahead to the installation instructions in the TL;DR section below.

For everyone else: I want to amend this answer which recommends using (what seems to be the hottest package management solution for Windows right now): Chocolatey

It gets the job done nice and quick. However, when I gave it a first try, it took me a while to make sense of the install instructions which are kinda convoluted. The install instructions go a bit like this (complete with what went through my head while going through it):

  • NOTE:
  • NOTE:
  • NOTE:

    three big-ass NOTEs before even knowing the basics... this makes me anxious... how wrong could things go!?

  • Installing With Restricted TLS

    not even sure what TLS is... Oh it's a good friend of SSL - Shouldn't this just be the default and just work out of the box? My browser can do HTTPS, NO PROBLEM! (just kidding... I know that SSL and TSL frequently cause a lot of pain in environments that have high security needs)

  • Option 1
  • Option 2

    eeh... great... Can't I just install?

  • Installing Behind a Proxy?

    Just... no...

  • Requirements

    uh boi...

  • Why does Chocolatey install where it does by default?


  • Before You Install


  • Can I install with a proxy?

    again with the proxy...

  • Can I install a particular version of Chocolatey?

    just any version would be fine, thank you...

  • Can I use Windows built-in compression instead of downloading 7zip?

    7zip?! Why do you even mention this?!

  • Non-Administrative Install
  • Now that sounds great!

    • "NOTE: This option should be a last resort and is considered to be an advanced scenario."
      • Sh$%!@T.

  • Alternative Installation Options


  • Command Line
    • "This really is the easiest method because it requires no configuration of PowerShell prior to executing it."

      And there you go!

While I really appreciate the fact that pitfalls and their possible solutions are discussed so extensively, maybe re-organizing them as such, and putting the Chocolatey installs in seconds promise to work by putting the "easiest method" first would be just awesome!

Named placeholders in string formatting

Based on the answer I created MapBuilder class:

public class MapBuilder {

    public static Map<String, Object> build(Object... data) {
        Map<String, Object> result = new LinkedHashMap<>();

        if (data.length % 2 != 0) {
            throw new IllegalArgumentException("Odd number of arguments");

        String key = null;
        Integer step = -1;

        for (Object value : data) {
            switch (step % 2) {
                case 0:
                    if (value == null) {
                        throw new IllegalArgumentException("Null key value");
                    key = (String) value;
                case 1:
                    result.put(key, value);

        return result;


then I created class StringFormat for String formatting:

public final class StringFormat {

    public static String format(String format, Object... args) {
        Map<String, Object> values =;

        for (Map.Entry<String, Object> entry : values.entrySet()) {
            String key = entry.getKey();
            Object value = entry.getValue();
            format = format.replace("$" + key, value.toString());

        return format;


which you could use like that:

String bookingDate = StringFormat.format("From $startDate to $endDate"), 
        "$startDate", formattedStartDate, 
        "$endDate", formattedEndDate

How can I remove space (margin) above HTML header?

Just for completeness, changing overflow to auto/hidden should do the trick too.

body {_x000D_
  margin: 0px;_x000D_
  padding: 0px;_x000D_
header {_x000D_
  margin: 0px;_x000D_
  padding: 0px;_x000D_
  height: 20em;_x000D_
  background-color: #C0C0C0;_x000D_
  overflow: auto;_x000D_
  <h1>OQ Online Judge</h1>_x000D_
  <form action="<?php echo base_url();?>/index.php/base/si" method="post">_x000D_
    <label for="email1">E-mail :</label>_x000D_
    <input type="text" name="email" id="email1">_x000D_
    <label for="password1">Password :</label>_x000D_
    <input type="password" name="password" id="password1">_x000D_
    <input type="submit" name="submit" value="Login">_x000D_

jquery can't get data attribute value

Iyap . Its work Case sensitive in data name data-x10

var variable = $('#myButton').data("x10"); // we get the value of custom data attribute

Changing date format in R

You could also use the parse_date_time function from the lubridate package:

[1] "2011-08-31"

parse_date_time returns a POSIXct object, so we use as.Date to get a date object. The first argument of parse_date_time specifies a date vector, the second argument specifies the order in which your format occurs. The orders argument makes parse_date_time very flexible.

Apache could not be started - ServerRoot must be a valid directory and Unable to find the specified module

Below solved. I have wrongly given the bin /directory/, so faced the issue:

if you installed apache at C:/httpd-2.4.41-o102s-x64-vc14-r2/Apache24
then the modules are at.. C:/httpd-2.4.41-o102s-x64-vc14-r2/Apache24/modules

So, the file           C:/httpd-2.4.41-o102s-x64-vc14-r2/Apache24/conf/httpd.conf
should have
       Define SRVROOT "C:/httpd-2.4.41-o102s-x64-vc14-r2/Apache24/"

Hope that helps

JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images

Wunderbart's post worked for me combined with statler's improvements. Adding a few more comments and syntax cleanup, and also passing back the orientation value and I have the following code feel free to use. Just call readImageFile() function below and you get back the transformed image and the original orientation.

const JpegOrientation = [

//Provided a image file, determines the orientation of the file based on the EXIF information.
//Calls the "callback" function with an index into the JpegOrientation array. 
//If the image is not a JPEG, returns 0. If  the orientation value cannot be read (corrupted file?) return -1.
function getOrientation(file, callback) {
    const reader = new FileReader();
    reader.onload = (e) => {

        const view = new DataView(;
        if (view.getUint16(0, false) !== 0xFFD8) {
            return callback(0);  //NOT A JPEG FILE
        const length = view.byteLength;
        let offset = 2;
        while (offset < length) {
            if (view.getUint16(offset+2, false) <= 8)   //unknown?
                return callback(-1);
            const marker = view.getUint16(offset, false);
            offset += 2;
            if (marker === 0xFFE1) {
                if (view.getUint32(offset += 2, false) !== 0x45786966) 
                    return callback(-1); //unknown?

                const little = view.getUint16(offset += 6, false) === 0x4949;
                offset += view.getUint32(offset + 4, little);
                const tags = view.getUint16(offset, little);
                offset += 2;
                for (var i = 0; i < tags; i++) {
                    if (view.getUint16(offset + (i * 12), little) === 0x0112) {
                        return callback(view.getUint16(offset + (i * 12) + 8, little));   //found orientation code
            else if ((marker & 0xFF00) !== 0xFF00) {
            else { 
                offset += view.getUint16(offset, false);
        return callback(-1); //unknown?

//Takes a jpeg image file as base64 and transforms it back to original, providing the
//transformed image in callback.  If the image is not a jpeg or is already in normal orientation,
//just calls the callback directly with the source.
//Set type to the desired output type if transformed, default is image/jpeg for speed.
function resetOrientation(srcBase64, srcOrientation, callback, type = "image/jpeg") {
    if (srcOrientation <= 1) {  //no transform needed
    const img = new Image();    

    img.onload = () => {
        const width = img.width;
        const height = img.height;
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext("2d");

        // set proper canvas dimensions before transform & export
        if (4 < srcOrientation && srcOrientation < 9) {
            canvas.width = height;
            canvas.height = width;
        } else {
            canvas.width = width;
            canvas.height = height;

        // transform context before drawing image
        switch (srcOrientation) {
              //case 1: normal, no transform needed
              case 2:  
                  ctx.transform(-1, 0, 0, 1, width, 0); 
              case 3:
                  ctx.transform(-1, 0, 0, -1, width, height); 
              case 4: 
                  ctx.transform(1, 0, 0, -1, 0, height); 
              case 5: 
                  ctx.transform(0, 1, 1, 0, 0, 0); 
              case 6: 
                  ctx.transform(0, 1, -1, 0, height, 0); 
              case 7: 
                  ctx.transform(0, -1, -1, 0, height, width); 
              case 8: 
                  ctx.transform(0, -1, 1, 0, 0, width); 

        // draw image
        ctx.drawImage(img, 0, 0);

        //export base64
        callback(canvas.toDataURL(type), srcOrientation);

    img.src = srcBase64;

//Read an image file, providing the returned data to callback. If the image is jpeg
//and is transformed according to EXIF info, transform it first.
//The callback function receives the image data and the orientation value (index into JpegOrientation)
export function readImageFile(file, callback) {

    getOrientation(file, (orientation) => {

        console.log("Read file \"" + + "\" with orientation: " + JpegOrientation[orientation]);

        const reader = new FileReader();
        reader.onload = () => {  //when reading complete

            const img = reader.result;
            resetOrientation(img, orientation, callback);
        reader.readAsDataURL(file);  //start read

fatal: early EOF fatal: index-pack failed

I got this error when git ran out of memory.

Freeing up some memory (in this case: letting a compile job finish) and trying again worked for me.

VBA Print to PDF and Save with Automatic File Name

Hopefully this is self explanatory enough. Use the comments in the code to help understand what is happening. Pass a single cell to this function. The value of that cell will be the base file name. If the cell contains "AwesomeData" then we will try and create a file in the current users desktop called AwesomeData.pdf. If that already exists then try AwesomeData2.pdf and so on. In your code you could just replace the lines filename = Application..... with filename = GetFileName(Range("A1"))

Function GetFileName(rngNamedCell As Range) As String
    Dim strSaveDirectory As String: strSaveDirectory = ""
    Dim strFileName As String: strFileName = ""
    Dim strTestPath As String: strTestPath = ""
    Dim strFileBaseName As String: strFileBaseName = ""
    Dim strFilePath As String: strFilePath = ""
    Dim intFileCounterIndex As Integer: intFileCounterIndex = 1

    ' Get the users desktop directory.
    strSaveDirectory = Environ("USERPROFILE") & "\Desktop\"
    Debug.Print "Saving to: " & strSaveDirectory

    ' Base file name
    strFileBaseName = Trim(rngNamedCell.Value)
    Debug.Print "File Name will contain: " & strFileBaseName

    ' Loop until we find a free file number
        If intFileCounterIndex > 1 Then
            ' Build test path base on current counter exists.
            strTestPath = strSaveDirectory & strFileBaseName & Trim(Str(intFileCounterIndex)) & ".pdf"
            ' Build test path base just on base name to see if it exists.
            strTestPath = strSaveDirectory & strFileBaseName & ".pdf"
        End If

        If (Dir(strTestPath) = "") Then
            ' This file path does not currently exist. Use that.
            strFileName = strTestPath
            ' Increase the counter as we have not found a free file yet.
            intFileCounterIndex = intFileCounterIndex + 1
        End If

    Loop Until strFileName <> ""

    ' Found useable filename
    Debug.Print "Free file name: " & strFileName
    GetFileName = strFileName

End Function

The debug lines will help you figure out what is happening if you need to step through the code. Remove them as you see fit. I went a little crazy with the variables but it was to make this as clear as possible.

In Action

My cell O1 contained the string "FileName" without the quotes. Used this sub to call my function and it saved a file.

Sub Testing()
    Dim filename As String: filename = GetFileName(Range("o1"))

    ActiveWorkbook.Worksheets("Sheet1").Range("A1:N24").ExportAsFixedFormat Type:=xlTypePDF, _
                                              filename:=filename, _
                                              Quality:=xlQualityStandard, _
                                              IncludeDocProperties:=True, _
                                              IgnorePrintAreas:=False, _
End Sub

Where is your code located in reference to everything else? Perhaps you need to make a module if you have not already and move your existing code into there.

How to sum up an array of integers in C#

If you don't prefer LINQ, it is better to use foreach loop to avoid out of index.

int[] arr = new int[] { 1, 2, 3 };
int sum = 0;
foreach (var item in arr)
   sum += item;

How do I see what character set a MySQL database / table / column is?

For databases:


In creating a Database (MySQL), default character set/collation is always LATIN, instead that you have selected a different one on initially creating your database

How can I enable "URL Rewrite" Module in IIS 8.5 in Server 2012?

First, install the URL Rewrite from a download or from the Web Platform Installer. Second, restart IIS. And, finally, close IIS and open again. The last step worked for me.

Is there "\n" equivalent in VBscript?

I think it's vbcrlf.

replace(s, vbcrlf, "<br />")

Visual Studio 2017 does not have Business Intelligence Integration Services/Projects

SSIS Integration with Visual Studio 2017 available from Aug 2017.

SSIS designer is now available for Visual Studio 2017! ARCHIVE

I installed in July 2018 and appears working fine. See Download link

Wireshark localhost traffic capture

I haven't actually tried this, but this answer from the web sounds promising:

Wireshark can't actually capture local packets on windows XP due to the nature of the windows TCP stack. When packets are sent and received on the same machine they don't seem to cross the network boundary that wireshark monitors.

However there is a way around this, you can route the local traffic out via your network gateway (router) by setting up a (temporary) static route on your windows XP machine.

Say your XP IP address is and your gateway (router) address is you could run the following command from windows XP command line to force all local traffic out and back across the network boundary, so wireshark could then track the data (note that wireshark will report packets twice in this scenario, once when they leave your pc and once when they return).

route add mask metric 1, accessed just now.

Bootstrap 4 navbar color

To change navbar background color:

.navbar-custom {

    background-color: yourcolor !important;

Ansible Ignore errors in tasks and fail at end of the playbook if any tasks had errors

Use Fail module.

  1. Use ignore_errors with every task that you need to ignore in case of errors.
  2. Set a flag (say, result = false) whenever there is a failure in any task execution
  3. At the end of the playbook, check if flag is set, and depending on that, fail the execution
- fail: msg="The execution has failed because of errors."
  when: flag == "failed"


Use register to store the result of a task like you have shown in your example. Then, use a task like this:

- name: Set flag
  set_fact: flag = failed
  when: "'FAILED' in command_result.stderr"

How to get the number of threads in a Java process

Generic solution that doesn't require a GUI like jconsole (doesn't work on remote terminals), ps works for non-java processes, doesn't require a JVM installed.

ps -o nlwp <pid>

Creating a simple login form

Check it - You can try this code for your login form design as you ask thank you.

Explain css -

First, we define property font style and width And after that I have defined form id to set background image and the border And after that I have to define the header text in tag and after that I have added new and define by.New to set background properties and width. Thanks

Create a file index.html

<!DOCTYPE html>
      <link rel="stylesheet" href="style.css">
      <div id="login_form">
         <div class="new"><span>enter login details</span></div>
         <!-- This is your header text-->
         <form name="f1" method="post" action="login.php" id="f1">
                  <td class="f1_label">User Name :</td>
                  <!-- This is your first Input Box Label-->
                     <input type="text" name="username" value="" /><!-- This is your first Input Box-->
                  <td class="f1_label">Password  :</td>
                  <!-- This is your Second Input Box Label-->
                     <input type="password" name="password" value=""  /><!-- This is your Second Input Box -->
                     <input type="submit" name="login" value="Log In" style="font-size:18px; " /><!-- This is your submit button -->

Create css file style.css

body {
    font-style: italic;
    width: 50%;
    margin: 0px auto;

#login_form {}

#f1 {
    background-color: #FFF;
    border-style: solid;
    border-width: 1px;
    padding: 23px 1px 20px 114px;

.f1_label {
    white-space: nowrap;

span {
    color: white;

.new {
    background: black;
    text-align: center;

Seeing if data is normally distributed in R

SnowsPenultimateNormalityTest certainly has its virtues, but you may also want to look at qqnorm.

X <- rlnorm(100)

Keyword not supported: "data source" initializing Entity Framework Context

Make sure you have Data Source and not DataSource in your connection string. The space is important. Trust me. I'm an idiot.

How to format a Date in MM/dd/yyyy HH:mm:ss format in JavaScript?

Try something like this

var d = new Date,
    dformat = [d.getMonth()+1,
               d.getFullYear()].join('/')+' '+

If you want leading zero's for values < 10, use this number extension

Number.prototype.padLeft = function(base,chr){
    var  len = (String(base || 10).length - String(this).length)+1;
    return len > 0? new Array(len).join(chr || '0')+this : this;
// usage
//=> 3..padLeft() => '03'
//=> 3..padLeft(100,'-') => '--3' 

Applied to the previous code:

var d = new Date,
    dformat = [(d.getMonth()+1).padLeft(),
               d.getFullYear()].join('/') +' ' +
//=> dformat => '05/17/2012 10:52:21'

See this code in jsfiddle

[edit 2019] Using ES20xx, you can use a template literal and the new padStart string extension.

var dt = new Date();_x000D_
    (dt.getMonth()+1).toString().padStart(2, '0')}/${_x000D_
    dt.getDate().toString().padStart(2, '0')}/${_x000D_
    dt.getFullYear().toString().padStart(4, '0')} ${_x000D_
    dt.getHours().toString().padStart(2, '0')}:${_x000D_
    dt.getMinutes().toString().padStart(2, '0')}:${_x000D_
    dt.getSeconds().toString().padStart(2, '0')}`_x000D_

See also

Android: Center an image

Simply add this to your ImageView.


setSupportActionBar toolbar cannot be applied to (android.widget.Toolbar) error

For adding a ToolBar that supports Material Design, the official documentation directions are probably the best to follow.

  1. Add the v7 appcompat support library.
  2. Make your activity extend AppCompatActivity.

    public class MyActivity extends AppCompatActivity {
      // ...
  3. Declare NoActionBar in the Manifest.

  4. Add a toolbar to your activity's xml layout.

  5. Call setSupportActionBar in the activity's onCreate.

    protected void onCreate(Bundle savedInstanceState) {
        Toolbar myToolbar = (Toolbar) findViewById(;

Note: You will have to import the following in the activity.


How do you set a JavaScript onclick event to a class with css

Asking about "a class" in the question title, the answer is getElementsByClassName:

  var hrefs = document.getElementsByClassName("YOUR-CLASS-NAME-HERE");
  for (var i = 0; i < hrefs.length; i++) {
   hrefs.item(i).addEventListener('click', function(e){
    e.preventDefault(); /*use if you want to prevent the original link following action*/

How can I print a quotation mark in C?

Without a backslash, special characters have a natural special meaning. With a backslash they print as they appear.

\   -   escape the next character
"   -   start or end of string
’   -   start or end a character constant
%   -   start a format specification
\\  -   print a backslash
\"  -   print a double quote
\’  -   print a single quote
%%  -   print a percent sign

The statement

printf("  \"  "); 

will print you the quotes. You can also print these special characters \a, \b, \f, \n, \r, \t and \v with a (slash) preceeding it.

SQL Query to fetch data from the last 30 days?

select status, timeplaced 
from orders 
where TIMEPLACED>'2017-06-12 00:00:00' 

jQuery Upload Progress and AJAX file upload

Uploading files is actually possible with AJAX these days. Yes, AJAX, not some crappy AJAX wannabes like swf or java.

This example might help you out:

(It also includes the drag/drop interface but that's easily ignored.)

Basically what it comes down to is this:

<input id="files" type="file" />

document.getElementById('files').addEventListener('change', function(e) {
    var file = this.files[0];
    var xhr = new XMLHttpRequest();
    (xhr.upload || xhr).addEventListener('progress', function(e) {
        var done = e.position || e.loaded
        var total = e.totalSize ||;
        console.log('xhr progress: ' + Math.round(done/total*100) + '%');
    xhr.addEventListener('load', function(e) {
        console.log('xhr upload complete', e, this.responseText);
    });'post', '/URL-HERE', true);


So basically what it comes down to is this =)


Where file is typeof Blob:

Another (better IMO) way is to use FormData. This allows you to 1) name a file, like in a form and 2) send other stuff (files too), like in a form.

var fd = new FormData;
fd.append('photo1', file);
fd.append('photo2', file2);
fd.append('other_data', 'foo bar');

FormData makes the server code cleaner and more backward compatible (since the request now has the exact same format as normal forms).

All of it is not experimental, but very modern. Chrome 8+ and Firefox 4+ know what to do, but I don't know about any others.

This is how I handled the request (1 image per request) in PHP:

if ( isset($_FILES['file']) ) {
    $filename = basename($_FILES['file']['name']);
    $error = true;

    // Only upload if on my home win dev machine
    if ( isset($_SERVER['WINDIR']) ) {
        $path = 'uploads/'.$filename;
        $error = !move_uploaded_file($_FILES['file']['tmp_name'], $path);

    $rsp = array(
        'error' => $error, // Used in JS
        'filename' => $filename,
        'filepath' => '/tests/uploads/' . $filename, // Web accessible
    echo json_encode($rsp);

What is the maximum length of a Push Notification alert text?

Here're some screenshots (banner, alert, & notification center)

AlertBannerNotification Center

CSS/HTML: Create a glowing border around an Input Field

You better use Twitter Bootstrap which contains all of this nice stuff inside. Particularly here is exactly what you want.

In addition, you can use different themes built for Twitter Bootstrap from this website

How to fix '.' is not an internal or external command error

Replacing forward(/) slash with backward(\) slash will do the job. The folder separator in Windows is \ not /

Add swipe to delete UITableViewCell

Add these two functions:

func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
    return true

func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if (editingStyle == UITableViewCellEditingStyle.Delete) {
        // handle delete (by removing the data from your array and updating the tableview)

Swift 3.0:

override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
    return true

override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if (editingStyle == UITableViewCellEditingStyle.delete) {
        // handle delete (by removing the data from your array and updating the tableview)

Swift 4.2

func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
    return true

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
    if (editingStyle == .delete) {
        // handle delete (by removing the data from your array and updating the tableview)

What is the role of the bias in neural networks?

In particular, Nate’s answer, zfy’s answer, and Pradi’s answer are great.

In simpler terms, biases allow for more and more variations of weights to be learnt/stored... (side-note: sometimes given some threshold). Anyway, more variations mean that biases add richer representation of the input space to the model's learnt/stored weights. (Where better weights can enhance the neural net’s guessing power)

For example, in learning models, the hypothesis/guess is desirably bounded by y=0 or y=1 given some input, in maybe some classification task... i.e some y=0 for some x=(1,1) and some y=1 for some x=(0,1). (The condition on the hypothesis/outcome is the threshold I talked about above. Note that my examples setup inputs X to be each x=a double or 2 valued-vector, instead of Nate's single valued x inputs of some collection X).

If we ignore the bias, many inputs may end up being represented by a lot of the same weights (i.e. the learnt weights mostly occur close to the origin (0,0). The model would then be limited to poorer quantities of good weights, instead of the many many more good weights it could better learn with bias. (Where poorly learnt weights lead to poorer guesses or a decrease in the neural net’s guessing power)

So, it is optimal that the model learns both close to the origin, but also, in as many places as possible inside the threshold/decision boundary. With the bias we can enable degrees of freedom close to the origin, but not limited to origin's immediate region.

Does calling clone() on an array also clone its contents?

The clone is a shallow copy of the array.

This test code prints:

[1, 2] / [1, 2]
[100, 200] / [100, 2]

because the MutableInteger is shared in both arrays as objects[0] and objects2[0], but you can change the reference objects[1] independently from objects2[1].

import java.util.Arrays;                                                                                                                                 

public class CloneTest {                                                                                                                                 
    static class MutableInteger {                                                                                                                        
        int value;                                                                                                                                       
        MutableInteger(int value) {                                                                                                                      
            this.value = value;                                                                                                                          
        public String toString() {                                                                                                                       
            return Integer.toString(value);                                                                                                              
    public static void main(String[] args) {                                                                                                             
        MutableInteger[] objects = new MutableInteger[] {
                new MutableInteger(1), new MutableInteger(2) };                                                
        MutableInteger[] objects2 = objects.clone();                                                                                                     
        System.out.println(Arrays.toString(objects) + " / " + 
        objects[0].value = 100;                                                                                                                          
        objects[1] = new MutableInteger(200);                                                                                                            
        System.out.println(Arrays.toString(objects) + " / " + 

Can jQuery provide the tag name?

I think you cannot use the nodeName in jQuery since nodeName is a DOM property and jQuery itself do not have a either a nodeName function or property. But based on the respondent who first mentioned about this nodeName stuff, this is how I was able to resolve the problem:

this.attr("id", "rnd" + this.attr("nodeName") + "_" + i.toString());

NOTE: this here is a jQuery object.

Android webview & localStorage

if you have multiple webview, localstorage does not work correctly.
two suggestion:

  1. using java database instead webview localstorage that " @Guillaume Gendre " explained.(of course it does not work for me)
  2. local storage work like json,so values store as "key:value" .you can add your browser unique id to it's key and using normal android localstorage

How to set the text/value/content of an `Entry` widget using a button in tkinter

You might want to use insert method. You can find the documentation for the Tkinter Entry Widget here.

This script inserts a text into Entry. The inserted text can be changed in command parameter of the Button.

from tkinter import *

def set_text(text):

win = Tk()

e = Entry(win,width=10)

b1 = Button(win,text="animal",command=lambda:set_text("animal"))

b2 = Button(win,text="plant",command=lambda:set_text("plant"))


Get the current user, within an ApiController action, without passing the userID as a parameter

In .Net Core use User.Identity.Name to get the Name claim of the user.

Difference between modes a, a+, w, w+, and r+ in built-in open function?

I find it important to note that python 3 defines the opening modes differently to the answers here that were correct for Python 2.

The Pyhton 3 opening modes are:

'r' open for reading (default)
'w' open for writing, truncating the file first
'x' open for exclusive creation, failing if the file already exists
'a' open for writing, appending to the end of the file if it exists
'b' binary mode
't' text mode (default)
'+' open a disk file for updating (reading and writing)
'U' universal newlines mode (for backwards compatibility; should not be used in new code)

The modes r, w, x, a are combined with the mode modifiers b or t. + is optionally added, U should be avoided.

As I found out the hard way, it is a good idea to always specify t when opening a file in text mode since r is an alias for rt in the standard open() function but an alias for rb in the open() functions of all compression modules (when e.g. reading a *.bz2 file).

Thus the modes for opening a file should be:

rt / wt / xt / at for reading / writing / creating / appending to a file in text mode and

rb / wb / xb / ab for reading / writing / creating / appending to a file in binary mode.

Use + as before.

Scanner vs. BufferedReader

Scanner is used for parsing tokens from the contents of the stream while BufferedReader just reads the stream and does not do any special parsing.

In fact you can pass a BufferedReader to a scanner as the source of characters to parse.

How to return part of string before a certain character?

You fiddle already does the job ... maybe you try to get the string before the double colon? (you really should edit your question) Then the code would go like this:

str.substring(0, str.indexOf(":"));

Where 'str' represents the variable with your string inside.

Click here for JSFiddle Example


var input_string = document.getElementById('my-input').innerText;
var output_element = document.getElementById('my-output');

var left_text = input_string.substring(0, input_string.indexOf(":"));

output_element.innerText = left_text;


  <strong id="my-input">Left Text:Right Text</strong>
  <strong id="my-output">XXX</strong>


body { font-family: Calibri, sans-serif; color:#555; }
h5 { margin-bottom: 0.8em; }
strong {
  padding: 0.5em 1em;
  background-color: cyan;
#my-output { background-color: gold; }

Skipping Iterations in Python

For this specific use-case using try..except..else is the cleanest solution, the else clause will be executed if no exception was raised.

NOTE: The else clause must follow all except clauses

for i in iterator:
        # Do something.
        # Handle exception
        # Continue doing something

How to check list A contains any value from list B?

For faster and short solution you can use HashSet instead of List.


Overlaps documentation

This method is an O(n) instead of O(n^2) with two lists.

Distinct by property of class with LINQ

Same approach as Guffa but as an extension method:

public static IEnumerable<T> DistinctBy<T, TKey>(this IEnumerable<T> items, Func<T, TKey> property)
    return items.GroupBy(property).Select(x => x.First());

Used as:

var uniqueCars = cars.DistinctBy(x => x.CarCode);

Free ASP.Net and/or CSS Themes

I wouldn't bother looking for ASP.NET stuff specifically (probably won't find any anyways). Finding a good CSS theme easily can be used in ASP.NET.

Here's some sites that I love for CSS goodness:

Jackson JSON: get node name from json-tree

Clarification Here:

While this will work:

 JsonNode rootNode = objectMapper.readTree(file);
 Iterator<Map.Entry<String, JsonNode>> fields = rootNode.fields();
 while (fields.hasNext()) {
    Map.Entry<String, JsonNode> entry =; + ":" + entry.getValue())

This will not:

JsonNode rootNode = objectMapper.readTree(file);

while (rootNode.fields().hasNext()) {
    Map.Entry<String, JsonNode> entry = rootNode.fields().next(); + ":" + entry.getValue())

So be careful to declare the Iterator as a variable and use that.

Be sure to use the fasterxml library rather than codehaus.

C#: how to get first char of a string?

In C# 8 you can use ranges.

myString[0..Math.Min(myString.Length, 1)]

Add a ? after myString to handle null strings.

Append text with .bat

You need to use ECHO. Also, put the quotes around the entire file path if it contains spaces.

One other note, use > to overwrite a file if it exists or create if it does not exist. Use >> to append to an existing file or create if it does not exist.

Overwrite the file with a blank line:

ECHO.>"C:\My folder\Myfile.log"

Append a blank line to a file:

ECHO.>>"C:\My folder\Myfile.log"

Append text to a file:

ECHO Some text>>"C:\My folder\Myfile.log"

Append a variable to a file:

ECHO %MY_VARIABLE%>>"C:\My folder\Myfile.log"

Is there a php echo/print equivalent in javascript

From w3school's page on JavaScript output,

JavaScript can "display" data in different ways:

Writing into an alert box, using window.alert().

Writing into the HTML output using document.write().

Writing into an HTML element, using innerHTML.

Writing into the browser console, using console.log().

How to set div width using ng-style

The syntax of ng-style is not quite that. It accepts a dictionary of keys (attribute names) and values (the value they should take, an empty string unsets them) rather than only a string. I think what you want is this:

<div ng-style="{ 'width' : width, 'background' : bgColor }"></div>

And then in your controller:

$scope.width = '900px';
$scope.bgColor = 'red';

This preserves the separation of template and the controller: the controller holds the semantic values while the template maps them to the correct attribute name.

Conversion between UTF-8 ArrayBuffer and String

The main problem of programmers looking for conversion from byte array into a string is UTF-8 encoding (compression) of unicode characters. This code will help you:

var getString = function (strBytes) {

    var MAX_SIZE = 0x4000;
    var codeUnits = [];
    var highSurrogate;
    var lowSurrogate;
    var index = -1;

    var result = '';

    while (++index < strBytes.length) {
        var codePoint = Number(strBytes[index]);

        if (codePoint === (codePoint & 0x7F)) {

        } else if (0xF0 === (codePoint & 0xF0)) {
            codePoint ^= 0xF0;
            codePoint = (codePoint << 6) | (strBytes[++index] ^ 0x80);
            codePoint = (codePoint << 6) | (strBytes[++index] ^ 0x80);
            codePoint = (codePoint << 6) | (strBytes[++index] ^ 0x80);
        } else if (0xE0 === (codePoint & 0xE0)) {
            codePoint ^= 0xE0;
            codePoint = (codePoint << 6) | (strBytes[++index] ^ 0x80);
            codePoint = (codePoint << 6) | (strBytes[++index] ^ 0x80);
        } else if (0xC0 === (codePoint & 0xC0)) {
            codePoint ^= 0xC0;
            codePoint = (codePoint << 6) | (strBytes[++index] ^ 0x80);

        if (!isFinite(codePoint) || codePoint < 0 || codePoint > 0x10FFFF || Math.floor(codePoint) != codePoint)
            throw RangeError('Invalid code point: ' + codePoint);

        if (codePoint <= 0xFFFF)
        else {
            codePoint -= 0x10000;
            highSurrogate = (codePoint >> 10) | 0xD800;
            lowSurrogate = (codePoint % 0x400) | 0xDC00;
            codeUnits.push(highSurrogate, lowSurrogate);
        if (index + 1 == strBytes.length || codeUnits.length > MAX_SIZE) {
            result += String.fromCharCode.apply(null, codeUnits);
            codeUnits.length = 0;

    return result;

All the best !

How to add new contacts in android

These examples are fine, I wanted to point out that you can achieve the same result using an Intent. The intent opens the Contacts app with the fields you provide already filled in.

It's up to the user to save the newly created contact.

You can read about it here:

Intent contactIntent = new Intent(ContactsContract.Intents.Insert.ACTION);

        .putExtra(ContactsContract.Intents.Insert.NAME, "Contact Name")
        .putExtra(ContactsContract.Intents.Insert.PHONE, "5555555555");

startActivityForResult(contactIntent, 1);

startActivityForResult() gives you the opportunity to see the result.

I've noticed the resultCode works on >5.0 devices,

but I have an older Samsung (<5) that always returns RESULT_CANCELLED (0).

Which I understand is the default return if an activity doesn't expect to return anything.

protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);

    if (requestCode == 1)
        if (resultCode == Activity.RESULT_OK) {
            Toast.makeText(this, "Added Contact", Toast.LENGTH_SHORT).show();
        if (resultCode == Activity.RESULT_CANCELED) {
            Toast.makeText(this, "Cancelled Added Contact", Toast.LENGTH_SHORT).show();

php hide ALL errors

to Hide All Errors:

ini_set('display_errors', 0);

to Show All Errors:

ini_set('display_errors', 1);

chart.js load totally new data

Please Learn how Chart.js (version 2 here) works and do it for whatever attribute you want:

1.Please suppose you have a bar chart like the below in your HTML:

<canvas id="your-chart-id" height="your-height" width="your-width"></canvas>

2.Please suppose you have a javascript code that fills your chart first time (for example when page is loaded):

var ctx = document.getElementById('your-chart-id').getContext('2d');
var chartInstance = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: your-lables-array,
        datasets: [{
            data: your-data-array,
            /*you can create random colors dynamically by ColorHash library []*/
            backgroundColor: (item) {
                return colorHash.hex(item);
    options: {
        maintainAspectRatio: false,
        scales: {
            yAxes: [ { ticks: {beginAtZero: true} } ]
        title: {display: true, fontSize: 16, text: 'chart title'},
        legend: {display: false}

Please suppose you want to update fully your dataset. It is very simple. Please look at the above code and see how is the path from your chart variable to data and then follow the below path:

  • select chartInstance var.
  • Then select data node inside the chartInstance.
  • Then select datasets node inside the data node.
    (note: As you can see, the datasets node is an array. so you have to specify which element of this array you want. here we have only one element in the datasets node. so we use datasets[0]
  • So select datasets[0]
  • Then select data node inside in the datasets[0].

This steps gives you[0].data and you can set new data and update the chart:[0].data = NEW-your-data-array
//finally update chart var:

Note: By following the above algorithm, you can simply achieve to each node you want.

Transposing a 2D-array in JavaScript

Since nobody so far mentioned a functional recursive approach here is my take. An adaptation of Haskell's Data.List.transpose.

var transpose = as => as.length ? as[0].length ? [as.reduce((rs, a) => a.length ? (rs.push(a[0]), rs) :
    rs, []
  ), ...transpose( => a.slice(1)))] :
  transpose(as.slice(1)) :
  mtx = [
    [1, 2],
    [1, 2, 3]

.as-console-wrapper {
  max-height: 100% !important

Eclipse memory settings when getting "Java Heap Space" and "Out of Memory"

-xms is the start memory (at the VM start), -xmx is the maximum memory for the VM

  • eclipse.ini : the memory for the VM running eclipse
  • jre setting : the memory for java programs run from eclipse
  • : the memory for your tomcat server

How can I render inline JavaScript with Jade / Pug?

simply use a 'script' tag with a dot after.

  var users = !{JSON.stringify(users).replace(/<\//g, "<\\/")}

Replace input type=file by an image

You can replace image automatically with newly selected image.

<div class="image-upload">
      <label for="file-input">
        <img id="previewImg" src="" style="width: 100px; height: 100px;" />

      <input id="file-input" type="file" onchange="previewFile(this);" style="display: none;" />

        function previewFile(input){
            var file = $("input[type=file]").get(0).files[0];

              var reader = new FileReader();

              reader.onload = function(){
                  $("#previewImg").attr("src", reader.result);


What is the difference between Jupyter Notebook and JupyterLab?

(I am using JupyterLab with Julia)

First thing is that Jupyter lab from my previous use offers more 'themes' which is great on the eyes, and also fontsize changes independent of the browser, so that makes it closer to that of an IDE. There are some specifics I like such as changing the 'code font size' and leaving the interface font size to be the same.

Major features that are great is

  • the drag and drop of cells so that you can easily rearrange the code
  • collapsing cells with a single mouse click and a small mark to remind of their placement

What is paramount though is the ability to have split views of the tabs and the terminal. If you use Emacs, then you probably enjoyed having multiple buffers with horizontal and vertical arrangements with one of them running a shell (terminal), and with jupyterlab this can be done, and the arrangement is made with drags and drops which in Emacs is typically done with sets of commands.

(I do not believe that there is a learning curve added to those that have not used the 'notebook' original version first. You can dive straight into this IDE experience)

Setting a property with an EventTrigger

I modified Neutrino's solution to make the xaml look less verbose when specifying the value:

Sorry for no pictures of the rendered xaml, just imagine a [=] hamburger button that you click and it turns into [<-] a back button and also toggles the visibility of a Grid.



    <Button x:Name="optionsButton">
            <i:EventTrigger EventName="Click">
                <local:SetterAction PropertyName="Visibility" Value="Collapsed" />
                <local:SetterAction PropertyName="Visibility" TargetObject="{Binding ElementName=optionsBackButton}" Value="Visible" />
                <local:SetterAction PropertyName="Visibility" TargetObject="{Binding ElementName=optionsPanel}" Value="Visible" />

        <glyphs:Hamburger Width="10" Height="10" />

    <Button x:Name="optionsBackButton" Visibility="Collapsed">
            <i:EventTrigger EventName="Click">
                <local:SetterAction PropertyName="Visibility" Value="Collapsed" />
                <local:SetterAction PropertyName="Visibility" TargetObject="{Binding ElementName=optionsButton}" Value="Visible" />
                <local:SetterAction PropertyName="Visibility" TargetObject="{Binding ElementName=optionsPanel}" Value="Collapsed" />

        <glyphs:Back Width="12" Height="11" />


<Grid Grid.RowSpan="2" x:Name="optionsPanel" Visibility="Collapsed">


You can also specify values this way like in Neutrino's solution:

<Button x:Name="optionsButton">
        <i:EventTrigger EventName="Click">
            <local:SetterAction PropertyName="Visibility" Value="{x:Static Visibility.Collapsed}" />
            <local:SetterAction PropertyName="Visibility" TargetObject="{Binding ElementName=optionsBackButton}" Value="{x:Static Visibility.Visible}" />
            <local:SetterAction PropertyName="Visibility" TargetObject="{Binding ElementName=optionsPanel}" Value="{x:Static Visibility.Visible}" />

    <glyphs:Hamburger Width="10" Height="10" />

And here's the code.

using System;
using System.ComponentModel;
using System.Reflection;
using System.Windows;
using System.Windows.Interactivity;

namespace Mvvm.Actions
    /// <summary>
    /// Sets a specified property to a value when invoked.
    /// </summary>
    public class SetterAction : TargetedTriggerAction<FrameworkElement>
        #region Properties

        #region PropertyName

        /// <summary>
        /// Property that is being set by this setter.
        /// </summary>
        public string PropertyName
            get { return (string)GetValue(PropertyNameProperty); }
            set { SetValue(PropertyNameProperty, value); }

        public static readonly DependencyProperty PropertyNameProperty =
            DependencyProperty.Register("PropertyName", typeof(string), typeof(SetterAction),
            new PropertyMetadata(String.Empty));


        #region Value

        /// <summary>
        /// Property value that is being set by this setter.
        /// </summary>
        public object Value
            get { return (object)GetValue(ValueProperty); }
            set { SetValue(ValueProperty, value); }

        public static readonly DependencyProperty ValueProperty =
            DependencyProperty.Register("Value", typeof(object), typeof(SetterAction),
            new PropertyMetadata(null));



        #region Overrides

        protected override void Invoke(object parameter)
            var target = TargetObject ?? AssociatedObject;

            var targetType = target.GetType();

            var property = targetType.GetProperty(PropertyName, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static | BindingFlags.Instance);
            if (property == null)
                throw new ArgumentException(String.Format("Property not found: {0}", PropertyName));

            if (property.CanWrite == false)
                throw new ArgumentException(String.Format("Property is not settable: {0}", PropertyName));

            object convertedValue;

            if (Value == null)
                convertedValue = null;

                var valueType = Value.GetType();
                var propertyType = property.PropertyType;

                if (valueType == propertyType)
                    convertedValue = Value;

                    var propertyConverter = TypeDescriptor.GetConverter(propertyType);

                    if (propertyConverter.CanConvertFrom(valueType))
                        convertedValue = propertyConverter.ConvertFrom(Value);

                    else if (valueType.IsSubclassOf(propertyType))
                        convertedValue = Value;

                        throw new ArgumentException(String.Format("Cannot convert type '{0}' to '{1}'.", valueType, propertyType));

            property.SetValue(target, convertedValue);


What is an undefined reference/unresolved external symbol error and how do I fix it?

Functions or class-methods are defined in source files with the inline specifier.

An example:-


#include "gum.h"
#include "foo.h"

int main()
    foo f;;
    return 0;

foo.h (1)

#pragma once

struct foo {
    void bar() const;

gum.h (1)

#pragma once

extern void gum();

foo.cpp (1)

#include "foo.h"
#include <iostream>

inline /* <- wrong! */ void foo::bar() const {
    std::cout << __PRETTY_FUNCTION__ << std::endl;

gum.cpp (1)

#include "gum.h"
#include <iostream>

inline /* <- wrong! */ void gum()
    std::cout << __PRETTY_FUNCTION__ << std::endl;

If you specify that gum (similarly, foo::bar) is inline at its definition then the compiler will inline gum (if it chooses to), by:-

  • not emitting any unique definition of gum, and therefore
  • not emitting any symbol by which the linker can refer to the definition of gum, and instead
  • replacing all calls to gum with inline copies of the compiled body of gum.

As a result, if you define gum inline in a source file gum.cpp, it is compiled to an object file gum.o in which all calls to gum are inlined and no symbol is defined by which the linker can refer to gum. When you link gum.o into a program together with another object file, e.g. main.o that make references to an external symbol gum, the linker cannot resolve those references. So the linkage fails:


g++ -c  main.cpp foo.cpp gum.cpp


$ g++ -o prog main.o foo.o gum.o
main.o: In function `main':
main.cpp:(.text+0x18): undefined reference to `gum()'
main.cpp:(.text+0x24): undefined reference to `foo::bar() const'
collect2: error: ld returned 1 exit status

You can only define gum as inline if the compiler can see its definition in every source file in which gum may be called. That means its inline definition needs to exist in a header file that you include in every source file you compile in which gum may be called. Do one of two things:

Either don't inline the definitions

Remove the inline specifier from the source file definition:

foo.cpp (2)

#include "foo.h"
#include <iostream>

void foo::bar() const {
    std::cout << __PRETTY_FUNCTION__ << std::endl;

gum.cpp (2)

#include "gum.h"
#include <iostream>

void gum()
    std::cout << __PRETTY_FUNCTION__ << std::endl;

Rebuild with that:

$ g++ -c  main.cpp foo.cpp gum.cpp
imk@imk-Inspiron-7559:~/develop/so/scrap1$ g++ -o prog main.o foo.o gum.o
imk@imk-Inspiron-7559:~/develop/so/scrap1$ ./prog
void gum()
void foo::bar() const


Or inline correctly

Inline definitions in header files:

foo.h (2)

#pragma once
#include <iostream>

struct foo {
    void bar() const  { // In-class definition is implicitly inline
        std::cout << __PRETTY_FUNCTION__ << std::endl;
// Alternatively...
#if 0
struct foo {
    void bar() const;
inline void foo::bar() const  {
    std::cout << __PRETTY_FUNCTION__ << std::endl;

gum.h (2)

#pragma once
#include <iostream>

inline void gum() {
    std::cout << __PRETTY_FUNCTION__ << std::endl;

Now we don't need foo.cpp or gum.cpp:

$ g++ -c main.cpp
$ g++ -o prog main.o
$ ./prog
void gum()
void foo::bar() const

Why doesn't TFS get latest get the latest?

just want to add TFS MSBuild does not support special characters on folders i.e. "@"

i had experienced in the past where one of our project folders named as External@Project1

we created a TFS Build definition to run a custom msbuild file then the workspace folder is not getting any contents at the External@Project1 folder during workspace get latest. It seems that tfs get is failing but does not show any error.

after some trial and error and renaming the folder to _Project1. voila we got files on the the folder (_Project1).

Closing Application with Exit button

Below used main.xml file

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android=""
android:orientation="vertical" android:layout_width="fill_parent"
<TextView android:layout_width="fill_parent"
    android:layout_height="wrap_content" android:id="@+id/txt1" android:text="txt1" />
<TextView android:layout_width="fill_parent"
    android:layout_height="wrap_content" android:id="@+id/txt2"   android:text="txt2"/>
<Button android:layout_width="fill_parent"
    android:layout_height="wrap_content" android:id="@+id/btn1"
    android:text="Close App" />

and file is below


import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class testprj extends Activity {
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState) {

    Button btn1 = (Button) findViewById(;
    btn1.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub

jQuery class within class selector

For this html:

<div class="outer">
     <div class="inner"></div>

This selector should work:

$('.outer > .inner')

Magento: get a static block as html in a phtml file

In the layout (app/design/frontend/your_theme/layout/default.xml):

    <cms_page> <!-- need to be redefined for your needs -->
        <reference name="content">
            <block type="cms/block" name="cms_newest_product" as="cms_newest_product">
                <action method="setBlockId"><block_id>newest_product</block_id></action>

In your phtml template:

<?php echo $this->getChildHtml('newest_product'); ?>

Don't forget about cache cleaning.

I think it help.

How can I convert String[] to ArrayList<String>

You can do the following:

String [] strings = new String [] {"1", "2" };
List<String> stringList = new ArrayList<String>(Arrays.asList(strings)); //new ArrayList is only needed if you absolutely need an ArrayList

What's the difference between subprocess Popen and call (how can I use them)?

The other answer is very complete, but here is a rule of thumb:

  • call is blocking:

    print('hello')  # only executed when notepad is closed
  • Popen is non-blocking:

    print('hello')  # immediately executed

Rails Root directory path?

You can access rails app path using variable RAILS_ROOT.

For example:

render :file => "#{RAILS_ROOT}/public/layouts/mylayout.html.erb"

Make a VStack fill the width of the screen in SwiftUI

I know this will not work for everyone, but I thought it interesting that just adding a Divider solves for this.

struct DividerTest: View {
var body: some View {
    VStack(alignment: .leading) {

Import Google Play Services library in Android Studio

I had similar issue Cannot resolve

I followed setup guide and it works!


  1. Installed/Updated Google Play Services, and Google Repository from SDK Manager
  2. Added dependency in build.gradle: compile ''
  3. Updated AndroidManifest.xml with <meta-data android:name="" android:value="@integer/google_play_services_version" />

How do I make HttpURLConnection use a proxy?

For Java 1.8 and higher you must set -Djdk.http.auth.tunneling.disabledSchemes= to make proxies with Basic Authorization working with https.

What is MVC and what are the advantages of it?

One of the major advantages of MVC which has not mentioned here is that MVC provides RESTful urls which enables SEO. When you name your Controllers and Actions wisely, it makes it easier for search engines to find your site if they only take a look at your site Urls. For example you have a car sale website and a page which displays available Lamborghini Veneno cars, instead of having referring to the page you can choose url for SEO purpose.

Here is a good answer to MVC Advantages and here is an article How to create a SEO friendly Url.

Why is the Android emulator so slow? How can we speed up the Android emulator?

Remove unwanted activation of some of the plugins at start-up by going to windows-->preference-->General-->Startup and shutdown. Also make sure you don't use those plugins in any of your views

Eclipse is not a word processor. Better to disable the spell check. Disabling spell check will reduce the eclipse burden by going to Windows-->Preference-->General-->Editors --> Text Editors-->Spelling

When eclipse builds the project, it will delete all output folders and rebuild classes built by other compilers. We can disable such features, as deleting the output folders and rebuilding will take sometime. Goto Windows-->Preference-->Java-->Compiler-->Building

Disabling label decorations which is of less use for you, will also help you to gain some performance . Goto Windows-->Preference-->General-->Appearance-->Label Decorations

Close unwanted projects and use working set option to move from one group of project to another smoothly.

You could also disable Eclipse automatic building, if it is not needed for you. Goto Project-->Build Automatically (uncheck it)

Do not keep lot of tabs opened in the editor. Better to have around 20 tabs . Regularly close the unused tabs. To open resource we can always use ctrl+shift+R and ctrl+shift+T (java resource) instead of opening lot of tabs

Disable unwanted plugins. Full J2EE eclipse version has an option to disable/uninstall plugins. Goto Help-->Software Updates-->Manage Configuration. Right click on any installed plugin to get disable option. If this option is not available then enable Classic Update by going to Windows-->Preference-->Capabilty and check classic update. Now the manage configuration option should be available in help menu

MySQL Update Column +1?

You can do:

UPDATE categories SET posts = posts + 1 WHERE category_id = 42;

Prevent scrolling of parent element when inner element scroll position reaches top/bottom?

Check out Leland Kwong's code.

Basic idea is to bind the wheeling event to the child element, and then use the native javascript property scrollHeight and the jquery property outerHeight of the child element to detect the end of the scroll, upon which return false to the wheeling event to prevent any scrolling.

var scrollableDist,curScrollPos,wheelEvent,dY;
$('#child-element').on('wheel', function(e){
  scrollableDist = $(this)[0].scrollHeight - $(this).outerHeight();
  curScrollPos = $(this).scrollTop();
  wheelEvent = e.originalEvent;
  dY = wheelEvent.deltaY;
  if ((dY>0 && curScrollPos >= scrollableDist) ||
      (dY<0 && curScrollPos <= 0)) {
    return false;

Why do we have to override the equals() method in Java?

From the article Override equals and hashCode in Java:

Default implementation of equals() class provided by java.lang.Object compares memory location and only return true if two reference variable are pointing to same memory location i.e. essentially they are same object.

Java recommends to override equals and hashCode method if equality is going to be defined by logical way or via some business logic: example:

many classes in Java standard library does override it e.g. String overrides equals, whose implementation of equals() method return true if content of two String objects are exactly same

Integer wrapper class overrides equals to perform numerical comparison etc.

JSON Naming Convention (snake_case, camelCase or PascalCase)

Seems that there's enough variation that people go out of their way to allow conversion from all conventions to others:

Notably, the mentioned Jackson JSON parser prefers bean_naming.

Best practice for using assert?

The English language word assert here is used in the sense of swear, affirm, avow. It doesn't mean "check" or "should be". It means that you as a coder are making a sworn statement here:

# I solemnly swear that here I will tell the truth, the whole truth, 
# and nothing but the truth, under pains and penalties of perjury, so help me FSM
assert answer == 42

If the code is correct, barring Single-event upsets, hardware failures and such, no assert will ever fail. That is why the behaviour of the program to an end user must not be affected. Especially, an assert cannot fail even under exceptional programmatic conditions. It just doesn't ever happen. If it happens, the programmer should be zapped for it.

String's Maximum length in Java - calling length() method

Considering the String class' length method returns an int, the maximum length that would be returned by the method would be Integer.MAX_VALUE, which is 2^31 - 1 (or approximately 2 billion.)

In terms of lengths and indexing of arrays, (such as char[], which is probably the way the internal data representation is implemented for Strings), Chapter 10: Arrays of The Java Language Specification, Java SE 7 Edition says the following:

The variables contained in an array have no names; instead they are referenced by array access expressions that use nonnegative integer index values. These variables are called the components of the array. If an array has n components, we say n is the length of the array; the components of the array are referenced using integer indices from 0 to n - 1, inclusive.

Furthermore, the indexing must be by int values, as mentioned in Section 10.4:

Arrays must be indexed by int values;

Therefore, it appears that the limit is indeed 2^31 - 1, as that is the maximum value for a nonnegative int value.

However, there probably are going to be other limitations, such as the maximum allocatable size for an array.

Why use @PostConstruct?

Also constructor based initialisation will not work as intended whenever some kind of proxying or remoting is involved.

The ct will get called whenever an EJB gets deserialized, and whenever a new proxy gets created for it...

how to use Spring Boot profiles

You can specify properties according profiles in one like here. Then mvn clean spring-boot:run should run it correct. It works for me

Simple regular expression for a decimal with a precision of 2


Will make things like 12. accepted. This is not what is commonly accepted but if in case you need to be “flexible”, that is one way to go. And of course [0-9] can be replaced with \d, but I guess it’s more readable this way.

How to get image width and height in OpenCV?

You can use rows and cols:

cout << "Width : " << src.cols << endl;
cout << "Height: " << src.rows << endl;

or size():

cout << "Width : " << src.size().width << endl;
cout << "Height: " << src.size().height << endl;

How to remove the underline for anchors(links)?


is a deprecated tag.


<span class="underline">My text</span>

with a CSS file containing...

    text-decoration: underline;

or just...

<span style="text-decoration:underline">My Text</span>

iOS 7 App Icons, Launch images And Naming Convention While Keeping iOS 6 Icons

You should use Asset Catalog:

I have investigated, how we can use Asset Catalog; Now it seems to be easy for me. I want to show you steps to add icons and splash in asset catalog.

Note: No need to make any entry in info.plist file :) And no any other configuration.

In below image, at right side, you will see highlighted area, where you can mention which icons you need. In case of mine, i have selected first four checkboxes; As its for my app requirements. You can select choices according to your requirements.

enter image description here

Now, see below image. As you will select any App icon then you will see its detail at right side selected area. It will help you to upload correct resolution icon. enter image description here

If Correct resolution image will not be added then following warning will come. Just upload the image with correct resolution. enter image description here

After uploading all required dimensions, you shouldn't get any warning. enter image description here

how to access master page control from content page

In the MasterPage.cs file add the property of Label like this:

public string ErrorMessage
        return lblMessage.Text;
        lblMessage.Text = value;

On your aspx page, just below the Page Directive add this:

<%@ Page Title="" Language="C#" MasterPageFile="Master Path Name"..... %>
<%@ MasterType VirtualPath="Master Path Name" %>   // Add this

And in your codebehind(aspx.cs) page you can then easily access the Label Property and set its text as required. Like this:

this.Master.ErrorMessage = "Your Error Message here";

how to open an URL in Swift3

import UIKit 
import SafariServices 

let url = URL(string: "")
let vc = SFSafariViewController(url: url!) 
present(vc, animated: true, completion: nil)

WAMP server, localhost is not working

Best try for windows: Open up cmd. run the following command: C:\wamp64\bin\apache\apache2.4.17\bin\httpd.exe -d C:/wamp64/bin/apache/apache2.4.17
C:\wamp64\bin\apache\apache2.4.17\bin\ Should be replaced with the path where your Apache is installed.
you use \ because \ is an escape character ;)
If the service could not start it will return the error.
For me it was the DocumentRoot was invalid :)

How do I create a link to add an entry to a calendar?

Here's an Add to Calendar service to serve the purpose for adding an event on

  1. Apple Calendar
  2. Google Calendar
  3. Outlook
  4. Outlook Online
  5. Yahoo! Calendar

The "Add to Calendar" button for events on websites and calendars is easy to install, language independent, time zone and DST compatible. It works perfectly in all modern browsers, tablets and mobile devices, and with Apple Calendar, Google Calendar, Outlook, and Yahoo Calendar.

<div title="Add to Calendar" class="addeventatc">
    Add to Calendar
    <span class="start">03/01/2018 08:00 AM</span>
    <span class="end">03/01/2018 10:00 AM</span>
    <span class="timezone">America/Los_Angeles</span>
    <span class="title">Summary of the event</span>
    <span class="description">Description of the event</span>
    <span class="location">Location of the event</span>

enter image description here

What does the 'b' character do in front of a string literal?

You can use JSON to convert it to dictionary

import json
data = b'{"key":"value"}'



This is an example from flask. Run this on terminal line:

import requests'http://localhost(example)/',json={'key':'value'})

In flask/

@app.route('/', methods=['POST'])
def api_script_add():
    print( # --> b'{"hi":"Hello"}'
return json.loads(


how to use python2.7 pip instead of default pip

There should be a binary called "pip2.7" installed at some location included within your $PATH variable.

You can find that out by typing

which pip2.7

This should print something like '/usr/local/bin/pip2.7' to your stdout. If it does not print anything like this, it is not installed. In that case, install it by running

$ wget
$ sudo python2.7

Now, you should be all set, and

which pip2.7

should return the correct output.

Why does integer division in C# return an integer and not a float?

Might be useful:

double a = 5.0/2.0;   
Console.WriteLine (a);      // 2.5

double b = 5/2;   
Console.WriteLine (b);      // 2

int c = 5/2;   
Console.WriteLine (c);      // 2

double d = 5f/2f;   
Console.WriteLine (d);      // 2.5

Responsive Images with CSS

.erb-image-wrapper img{
    max-width:100% !important;

Worked for me.
Thanks for MrMisterMan for his assistance.

How to TryParse for Enum value?

Have a look at the Enum class (struct ? ) itself. There is a Parse method on that but I'm not sure about a tryparse.

Python string to unicode

Unicode escapes only work in unicode strings, so this


is actually a string of 6 characters: '\', 'u', '2', '0', '2', '6'.

To make unicode out of this, use decode('unicode-escape'):

print repr(a)
print repr(a.decode('unicode-escape'))

## '\\u2026'
## u'\u2026'

Quickly getting to YYYY-mm-dd HH:MM:SS in Perl

Use strftime in the standard POSIX module. The arguments to strftime in Perl’s binding were designed to align with the return values from localtime and gmtime. Compare

strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)


my          ($sec,$min,$hour,$mday,$mon,$year,$wday,     $yday,     $isdst) = gmtime(time);

Example command-line use is

$ perl -MPOSIX -le 'print strftime "%F %T", localtime $^T'

or from a source file as in

use POSIX;

print strftime "%F %T", localtime time;

Some systems do not support the %F and %T shorthands, so you will have to be explicit with

print strftime "%Y-%m-%d %H:%M:%S", localtime time;


print strftime "%Y-%m-%d %H:%M:%S", gmtime time;

Note that time returns the current time when called whereas $^T is fixed to the time when your program started. With gmtime, the return value is the current time in GMT. Retrieve time in your local timezone with localtime.

Find elements inside forms and iframe using Java and Selenium WebDriver

Before you try searching for the elements within the iframe you will have to switch Selenium focus to the iframe.

Try this before searching for the elements within the iframe:


SQLite table constraint - unique on multiple columns

Be careful how you define the table for you will get different results on insert. Consider the following

    ('Alice', 'Some title'),
    ('Bob', 'Palindromic guy'),
    ('Charles', 'chucky cheese'),
    ('Alice', 'Some other title') 
    ON CONFLICT(a) DO UPDATE SET b=excluded.b;
    ('Alice', 'Some title'),
    ('Bob', 'Palindromic guy'),
    ('Charles', 'chucky cheese'),
    ('Alice', 'Some other title');

$ sqlite3 test.sqlite
SQLite version 3.28.0 2019-04-16 19:49:53
Enter ".help" for usage hints.
sqlite> INSERT INTO t1 (a, b) VALUES
   ...>     ('Alice', 'Some title'),
   ...>     ('Bob', 'Palindromic guy'),
   ...>     ('Charles', 'chucky cheese'),
   ...>     ('Alice', 'Some other title') 
   ...>     ON CONFLICT(a) DO UPDATE SET b=excluded.b;
sqlite> INSERT INTO t2 (a, b) VALUES
   ...>     ('Alice', 'Some title'),
   ...>     ('Bob', 'Palindromic guy'),
   ...>     ('Charles', 'chucky cheese'),
   ...>     ('Alice', 'Some other title');
sqlite> .mode col
sqlite> .headers on
sqlite> select * from t1;
id          a           b               
----------  ----------  ----------------
1           Alice       Some other title
2           Bob         Palindromic guy 
3           Charles     chucky cheese   
sqlite> select * from t2;
id          a           b              
----------  ----------  ---------------
2           Bob         Palindromic guy
3           Charles     chucky cheese  
4           Alice       Some other titl

While the insert/update effect is the same, the id changes based on the table definition type (see the second table where 'Alice' now has id = 4; the first table is doing more of what I expect it to do, keep the PRIMARY KEY the same). Be aware of this effect.

Removing empty rows of a data file in R

Alternative solution for rows of NAs using janitor package

myData %>% remove_empty("rows")

jQuery Array of all selected checkboxes (by class)

var matches = [];
$(".className:checked").each(function() {

How to use relative paths without including the context root name?

Just use <c:url>-tag with an application context relative path.

When the value parameter starts with an /, then the tag will treat it as an application relative url, and will add the application-name to the url. Example:


<c:url value="/templates/style/main.css" var="mainCssUrl" />`
<link rel="stylesheet" href="${mainCssUrl}" />
<c:url value="/home" var="homeUrl" />`
<a href="${homeUrl}">home link</a>

will become this html, with an domain relative url:

<link rel="stylesheet" href="/AppName/templates/style/main.css" />
<a href="/AppName/home">home link</a>

Android Horizontal RecyclerView scroll Direction

Assuming you use LinearLayoutManager in your RecyclerView, then you can pass true as third argument in the LinearLayoutManager constructor.

For example:

mRecyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, true));

If you are using the StaggeredGridLayoutManager, then you can use the setReverseLayout method it provides.

How can I assign an ID to a view programmatically?

You can just use the View.setId(integer) for this. In the XML, even though you're setting a String id, this gets converted into an integer. Due to this, you can use any (positive) Integer for the Views you add programmatically.

According to View documentation

The identifier does not have to be unique in this view's hierarchy. The identifier should be a positive number.

So you can use any positive integer you like, but in this case there can be some views with equivalent id's. If you want to search for some view in hierarchy calling to setTag with some key objects may be handy.

Credits to this answer.

Can we pass model as a parameter in RedirectToAction?

i did find something like this, helps get rid of hardcoded tempdata tags

public class AccountController : Controller
    public ActionResult Index(IndexPresentationModel model)
        return View(model);

    public ActionResult Save(SaveUpdateModel model)
        // save the information

        var presentationModel = new IndexPresentationModel();

        presentationModel.Message = model.Message;

        return this.RedirectToAction(c => c.Index(presentationModel));

How to implement class constructor in Visual Basic?

A class with a field:

Public Class MyStudent
   Public StudentId As Integer

The constructor:

    Public Sub New(newStudentId As Integer)
        StudentId = newStudentId
    End Sub
End Class

Check existence of directory and create if doesn't exist

In terms of general architecture I would recommend the following structure with regard to directory creation. This will cover most potential issues and any other issues with directory creation will be detected by the dir.create call.

mainDir <- "~"
subDir <- "outputDirectory"

if (file.exists(paste(mainDir, subDir, "/", sep = "/", collapse = "/"))) {
    cat("subDir exists in mainDir and is a directory")
} else if (file.exists(paste(mainDir, subDir, sep = "/", collapse = "/"))) {
    cat("subDir exists in mainDir but is a file")
    # you will probably want to handle this separately
} else {
    cat("subDir does not exist in mainDir - creating")
    dir.create(file.path(mainDir, subDir))

if (file.exists(paste(mainDir, subDir, "/", sep = "/", collapse = "/"))) {
    # By this point, the directory either existed or has been successfully created
    setwd(file.path(mainDir, subDir))
} else {
    cat("subDir does not exist")
    # Handle this error as appropriate

Also be aware that if ~/foo doesn't exist then a call to dir.create('~/foo/bar') will fail unless you specify recursive = TRUE.

How to compile C programming in Windows 7?

MinGW uses a fairly old version of GCC (3.4.5, I believe), and hasn't been updated in a while. If you're already comfortable with the GCC toolset and just looking to get your feet wet in Windows programming, this may be a good option for you. There are lots of great IDEs available that use this compiler.

Edit: Apparently I was wrong; that's what I get for talking about something I know very little about. Tauran points out that there is a project that aims to provide the MinGW toolkit with the current version of GCC. You can download it from their website.

However, I'm not sure that I can recommend it for serious Windows development. If you're not a idealistic fanboy who can't stomach the notion of ever using Microsoft software, I highly recommend investigating Visual Studio, which comes bundled with Microsoft's C/C++ compiler. The Express version (which includes the same compiler as all the paid-for editions) is absolutely free for download. In addition to the compiler, Visual Studio also provides a world-class IDE that makes developing Windows-specific applications much easier. Yes, detractors will ramble on about the fact that it's not fully standards-compliant, but such is the world of writing Windows applications. They're never going to be truly portable once you include windows.h, so most of the idealistic dedication just ends up being a waste of time.

Why Local Users and Groups is missing in Computer Management on Windows 10 Home?

Windows 10 Home Edition does not have Local Users and Groups option so that is the reason you aren't able to see that in Computer Management.

You can use User Accounts by pressing Window+R, typing netplwiz and pressing OK as described here.

How do I format a number to a dollar amount in PHP

i tried money_format() but it didn't work for me at all. then i tried the following one. it worked perfect for me. hopefully it will work in right way for you too.. :)

you should use this one

number_format($money, 2,'.', ',')

it will show money number in terms of money format up to 2 decimal.

Different CURRENT_TIMESTAMP and SYSDATE in oracle

SYSDATE returns the system date, of the system on which the database resides

CURRENT_TIMESTAMP returns the current date and time in the session time zone, in a value of datatype TIMESTAMP WITH TIME ZONE

execute this comman


and it will provide you the same result.

How to use AND in IF Statement

If there are no typos in the question, you got the conditions wrong:

You said this:

IF cells (i,"A") contains the text 'Miami'

...but your code says:

If Cells(i, "A") <> "Miami"

--> <> means that the value of the cell is not equal to "Miami", so you're not checking what you think you are checking.

I guess you want this instead:

If Cells(i, "A") like "*Miami*"


Sorry, but I can't really help you more. As I already said in a comment, I'm no Excel VBA expert.
Normally I would open Excel now and try your code myself, but I don't even have Excel on any of my machines at home (I use OpenOffice).

Just one general thing: can you identify the row that does not work?
Maybe this helps someone else to answer the question.

Does it ever execute (or at least try to execute) the Cells(i, "C").Value = "BA" line?
Or is the If Cells(i, "A") like "*Miami*" stuff already False?
If yes, try checking just one cell and see if that works.

Forcing label to flow inline with input that they label

Why don't You just use:

label {
    display: block;
    width: 50px;
    height: 24px;
    float: left;

how to use jQuery ajax calls with node.js

I suppose your html page is hosted on a different port. Same origin policy requires in most browsers that the loaded file be on the same port than the loading file.

How can I save an image with PIL?

The error regarding the file extension has been handled, you either use BMP (without the dot) or pass the output name with the extension already. Now to handle the error you need to properly modify your data in the frequency domain to be saved as an integer image, PIL is telling you that it doesn't accept float data to save as BMP.

Here is a suggestion (with other minor modifications, like using fftshift and numpy.array instead of numpy.asarray) for doing the conversion for proper visualization:

import sys
import numpy
from PIL import Image

img =[1]).convert('L')

im = numpy.array(img)
fft_mag = numpy.abs(numpy.fft.fftshift(numpy.fft.fft2(im)))

visual = numpy.log(fft_mag)
visual = (visual - visual.min()) / (visual.max() - visual.min())

result = Image.fromarray((visual * 255).astype(numpy.uint8))'out.bmp')

How to get Month Name from Calendar?

It returns English name of the month. 04 returns APRIL and so on.

String englishMonth (int month){
        return Month.of(month);

Software Design vs. Software Architecture

Software design has a longer history while the term software architecture is barely 20 years old. Hence, it is going through growing pains right now.

Academics tend to see Architecture as part of the larger field of software design. Although there is growing recognition that Arch is a field within it's own.

Practitioners tend to see Arch as high-level design decisions that are strategic and can be costly in a project to undo.

The exact line between Arch and design depends on the software domain. For instance, in the domain of Web Applications, the layered architecture is gaining the most popularity currently (Biz Logic Layer, Data Access Layer, etc.) The lower level parts of this Arch are considered design (class diagrams, method signatures, etc.) This would be defined differently in the domains of embedded systems, operating systems, compilers, etc.

Python re.sub replace with matched content

Simply use \1 instead of $1:

In [1]: import re

In [2]: method = 'images/:id/huge'

In [3]: re.sub(r'(:[a-z]+)', r'<span>\1</span>', method)
Out[3]: 'images/<span>:id</span>/huge'

Also note the use of raw strings (r'...') for regular expressions. It is not mandatory but removes the need to escape backslashes, arguably making the code slightly more readable.


I had similar problem when I tried to build a signed apk for my app.

Strange, it happened only when I wanted to build a release apk, while on debug apk everything worked OK.

Finally, looking on this thread, I checked for support library duplications in build.gradle and removed any duplications but this wasn't enough..

I had to do clean project and only then finally I've got it to work.

How do I solve this error, "error while trying to deserialize parameter"

In my case; my WCF service function was using List<byte> Types parameter and i was getting this exception in the client side. Then i changed it to byte[] Types, updated service reference and problem is solved.

How to implement class constants?

Constants can be declare outside of classes and use within your class. Otherwise the get property is a nice workaround

const MY_CONSTANT: string = "wazzup";

export class MyClass {

    public myFunction() {


SQL how to increase or decrease one for a int column in one command

To answer the first:

UPDATE Orders SET Quantity = Quantity + 1 WHERE ...

To answer the second:

There are several ways to do this. Since you did not specify a database, I will assume MySQL.

  1. INSERT INTO table SET x=1, y=2 ON DUPLICATE KEY UPDATE x=x+1, y=y+2
  2. REPLACE INTO table SET x=1, y=2

They both can handle your question. However, the first syntax allows for more flexibility to update the record rather than just replace it (as the second one does).

Keep in mind that for both to exist, there has to be a UNIQUE key defined...

Angular.js vs Knockout.js vs Backbone.js

It depends on the nature of your application. And, since you did not describe it in great detail, it is an impossible question to answer. I find Backbone to be the easiest, but I work in Angular all day. Performance is more up to the coder than the framework, in my opinion.

Are you doing heavy DOM manipulation? I would use jQuery and Backbone.

Very data driven app? Angular with its nice data binding.

Game programming? None - direct to canvas; maybe a game engine.

How can I do string interpolation in JavaScript?

Douglas Crockford's Remedial JavaScript includes a String.prototype.supplant function. It is short, familiar, and easy to use:

String.prototype.supplant = function (o) {
    return this.replace(/{([^{}]*)}/g,
        function (a, b) {
            var r = o[b];
            return typeof r === 'string' || typeof r === 'number' ? r : a;

// Usage:
alert("I'm {age} years old!".supplant({ age: 29 }));
alert("The {a} says {n}, {n}, {n}!".supplant({ a: 'cow', n: 'moo' }));

If you don't want to change String's prototype, you can always adapt it to be standalone, or place it into some other namespace, or whatever.

Total Number of Row Resultset getRow Method

BalusC's answer is right! but I have to mention according to the user instance variable such as:

total = rSet.getRow();

and then which you are missing


the remaining code is same you will get your desire result.

Visual Studio 2017 - Could not load file or assembly 'System.Runtime, Version=' or one of its dependencies

This issue happens when you reference a .NET Standard project from a .NET 4.x project: none of the .NET Standard project's nuget package references are brought in as dependencies.

I resolved by add System.Runtime 4.3 and NETStandard.Library package and !!important!! I use refactor tool to look up the System.Runtime.dll version, It is not 4.3 and then add an bindingRedirect in .config

    <assemblyIdentity name="System.Runtime" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
    <bindingRedirect oldVersion="" newVersion="" />

Order by in Inner Join

Avoid SELECT * in your main query.

Avoid duplicate columns: the JOIN condition ensures One.One_Name and two.One_Name will be equal therefore you don't need to return both in the SELECT clause.

Avoid duplicate column names: rename One.ID and Two.ID using 'aliases'.

Add an ORDER BY clause using the column names ('alises' where applicable) from the SELECT clause.

Suggested re-write:

SELECT T1.ID AS One_ID, T1.One_Name, 
       T2.ID AS Two_ID, T2.Two_name
  FROM One AS T1
       INNER JOIN two AS T2
          ON T1.One_Name = T2.One_Name
    BY One_ID;

Git Symlinks in Windows

I just tried with Git 2.30.0 (released 2020-12-28).

This is NOT a full answer but a few useful tidbits nonetheless. (Feel free to cannibalize for your own answer.)

There's a documentation link when installing Git for Windows

enter image description here

This link takes you here:

And this is quite a longish discussion.

Also symbolic links keep popping up in the release notes. As of 2.30.0 this here is still listed as a "Known issue":

On Windows 10 before 1703, or when Developer Mode is turned off, special permissions are required when cloning repositories with symbolic links, therefore support for symbolic links is disabled by default. Use git clone -c core.symlinks=true <URL> to enable it, see details here.

How to retrieve form values from HTTPPOST, dictionary or?

Simply, you can use FormCollection like:

public ActionResult SubmitAction(FormCollection collection)
     // Get Post Params Here
 string var1 = collection["var1"];

You can also use a class, that is mapped with Form values, and mvc engine automagically fills it:

//Defined in another file
class MyForm
  public string var1 { get; set; }

public ActionResult SubmitAction(MyForm form)
  string var1 = form1.Var1;

Insert data into table with result from another select query

Below is an example of such a query:

INSERT INTO [93275].[93276].[93277].[93278] ( [Mobile Number], [Mobile Series], [Full Name], [Full Address], [Active Date], company ) IN 'I:\For Test\90-Mobile Series.accdb
SELECT [1].[Mobile Number], [1].[Mobile Series], [1].[Full Name], [1].[Full Address], [1].[Active Date], [1].[Company Name]
WHERE ((([1].[Mobile Series])="93275" Or ([1].[Mobile Series])="93276")) OR ((([1].[Mobile Series])="93277"));OR ((([1].[Mobile Series])="93278"));

How to add items into a numpy array

np.insert can also be used for the purpose

import numpy as np
a = np.array([[1, 3, 4],
              [1, 2, 3],
              [1, 2, 1]])
x = 5
index = 3 # the position for x to be inserted before
np.insert(a, index, x, axis=1)
array([[1, 3, 4, 5],
       [1, 2, 3, 5],
       [1, 2, 1, 5]])

index can also be a list/tuple

>>> index = [1, 1, 3] # equivalently (1, 1, 3)
>>> np.insert(a, index, x, axis=1)
array([[1, 5, 5, 3, 4, 5],
       [1, 5, 5, 2, 3, 5],
       [1, 5, 5, 2, 1, 5]])

or a slice

>>> index = slice(0, 3)
>>> np.insert(a, index, x, axis=1)
array([[5, 1, 5, 3, 5, 4],
       [5, 1, 5, 2, 5, 3],
       [5, 1, 5, 2, 5, 1]]) Invalid Keystore format

go to build clean the project then rebuild your project it worked for me.

Saving any file to in the database, just convert it to a byte array?

I'll describe the way I've stored files, in SQL Server and Oracle. It largely depends on how you are getting the file, in the first place, as to how you will get its contents, and it depends on which database you are using for the content in which you will store it for how you will store it. These are 2 separate database examples with 2 separate methods of getting the file that I used.

SQL Server

Short answer: I used a base64 byte string I converted to a byte[] and store in a varbinary(max) field.

Long answer:

Say you're uploading via a website, so you're using an <input id="myFileControl" type="file" /> control, or React DropZone. To get the file, you're doing something like var myFile = document.getElementById("myFileControl")[0]; or myFile = this.state.files[0];.

From there, I'd get the base64 string using code here: Convert input=file to byte array (use function UploadFile2).

Then I'd get that string, the file name ( and type (myFile.type) into a JSON object:

var myJSONObj = {
    file: base64string,
    type: myFile.type,

and post the file to an MVC server backend using XMLHttpRequest, specifying a Content-Type of application/json: xhr.send(JSON.stringify(myJSONObj);. You have to build a ViewModel to bind it with:

public class MyModel
    public string file { get; set; }
    public string title { get; set; }
    public string type { get; set; }

and specify [FromBody]MyModel myModelObj as the passed in parameter:

[System.Web.Http.HttpPost]  // required to spell it out like this if using ApiController, or it will default to System.Mvc.Http.HttpPost
public virtual ActionResult Post([FromBody]MyModel myModelObj)

Then you can add this into that function and save it using Entity Framework:

tblAtchm.Name =;
tblAtchm.Type = myModelObj.type;
tblAtchm.File = System.Convert.FromBase64String(myModelObj.file);
EntityFrameworkContextName ef = new EntityFrameworkContextName();

tblAtchm.File = System.Convert.FromBase64String(myModelObj.file); being the operative line.

You would need a model to represent the database table:

    public byte[] File { get; set; }  // notice this change
    public string Name { get; set; }
    public string Type { get; set; }

This will save the data into a varbinary(max) field as a byte[]. Name and Type were nvarchar(250) and nvarchar(10), respectively. You could include size by adding it to your table as an int column & MY_ATTACHMENT_TABLE_MODEL as public int Size { get; set;}, and add in the line tblAtchm.Size = System.Convert.FromBase64String(myModelObj.file).Length; above.


Short answer: Convert it to a byte[], assign it to an OracleParameter, add it to your OracleCommand, and update your table's BLOB field using a reference to the parameter's ParameterName value: :BlobParameter

Long answer: When I did this for Oracle, I was using an OpenFileDialog and I retrieved and sent the bytes/file information this way:

byte[] array;
OracleParameter param = new OracleParameter();
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
dlg.Filter = "Image Files (*.jpg, *.jpeg, *.jpe)|*.jpg;*.jpeg;*.jpe|Document Files (*.doc, *.docx, *.pdf)|*.doc;*.docx;*.pdf"
if (dlg.ShowDialog().Value == true)
    string fileName = dlg.FileName;
    using (FileStream fs = File.OpenRead(fileName)
        array = new byte[fs.Length];
        using (BinaryReader binReader = new BinaryReader(fs))
            array = binReader.ReadBytes((int)fs.Length);

        // Create an OracleParameter to transmit the Blob
        param.OracleDbType = OracleDbType.Blob;
        param.ParameterName = "BlobParameter";
        param.Value = array;  // <-- file bytes are here
    fileName = fileName.Split('\\')[fileName.Split('\\').Length-1]; // gets last segment of the whole path to just get the name

    string fileType = fileName.Split('.')[1];
    if (fileType == "doc" || fileType == "docx" || fileType == "pdf")
        fileType = "application\\" + fileType;
        fileType = "image\\" + fileType;

    // SQL string containing reference to BlobParameter named above
    string sql = String.Format("INSERT INTO YOUR_TABLE (FILE_NAME, FILE_TYPE, FILE_SIZE, FILE_CONTENTS, LAST_MODIFIED) VALUES ('{0}','{1}',{2},:BlobParamerter, SYSDATE)", fileName, fileType, array.Length);

    // Do Oracle Update
    RunCommand(sql, param);

And inside the Oracle update, done with ADO:

public void RunCommand(string sql, OracleParameter param)
    OracleConnection oraConn = null;
    OracleCommand oraCmd = null;
        string connString = GetConnString();
        oraConn = OracleConnection(connString);
        using (oraConn)
            if (OraConnection.State == ConnectionState.Open)


            oraCmd = new OracleCommand(strSQL, oraConnection);

            // Add your OracleParameter
            if (param != null)

            // Execute the command
    catch (OracleException err)
       // handle exception 

private string GetConnString()
    string host = System.Configuration.ConfigurationManager.AppSettings["host"].ToString();
    string port = System.Configuration.ConfigurationManager.AppSettings["port"].ToString();
    string serviceName = System.Configuration.ConfigurationManager.AppSettings["svcName"].ToString();
    string schemaName = System.Configuration.ConfigurationManager.AppSettings["schemaName"].ToString();
    string pword = System.Configuration.ConfigurationManager.AppSettings["pword"].ToString(); // hopefully encrypted

    if (String.IsNullOrEmpty(host) || String.IsNullOrEmpty(port) || String.IsNullOrEmpty(serviceName) || String.IsNullOrEmpty(schemaName) || String.IsNullOrEmpty(pword))
        return "Missing Param";
        pword = decodePassword(pword);  // decrypt here
        return String.Format(
           "Data Source=(DESCRIPTION =(ADDRESS = ( PROTOCOL = TCP)(HOST = {2})(PORT = {3}))(CONNECT_DATA =(SID = {4})));User Id={0};Password={1};",

And the datatype for the FILE_CONTENTS column was BLOB, the FILE_SIZE was NUMBER(10,0), LAST_MODIFIED was DATE, and the rest were NVARCHAR2(250).

trying to animate a constraint in swift

It's very important to point out that view.layoutIfNeeded() applies to the view subviews only.

Therefore to animate the view constraint, it is important to call it on the view-to-animate superview as follows:

    topConstraint.constant = heightShift

    UIView.animate(withDuration: 0.3) {

        // request layout on the *superview*

An example for a simple layout as follows:

class MyClass {

    /// Container view
    let container = UIView()
        /// View attached to container
        let view = UIView()

    /// Top constraint to animate
    var topConstraint = NSLayoutConstraint()

    /// Create the UI hierarchy and constraints
    func createUI() {

        // Create the top constraint
        topConstraint = view.topAnchor.constraint(equalTo: container.topAnchor, constant: 0)

        view.translatesAutoresizingMaskIntoConstraints = false

        // Activate constaint(s)

    /// Update view constraint with animation
    func updateConstraint(heightShift: CGFloat) {
        topConstraint.constant = heightShift

        UIView.animate(withDuration: 0.3) {

            // request layout on the *superview*

How to check is Apache2 is stopped in Ubuntu?

You can also type "top" and look at the list of running processes.

Regular expression for 10 digit number without any special characters

Use this regular expression to match ten digits only:


To find a sequence of ten consecutive digits anywhere in a string, use:


Note that this will also find the first 10 digits of an 11 digit number. To search anywhere in the string for exactly 10 consecutive digits and not more you can use negative lookarounds:


How many times a substring occurs

Here's the solution in Python 3 and case insensitive:

s = 'foo bar foo'.upper()
sb = 'foo'.upper()
results = 0
sub_len = len(sb)
for i in range(len(s)):
    if s[i:i+sub_len] == sb:
        results += 1

Get HTML code using JavaScript with a URL

There is a tutorial on how to use Ajax here:

This is an example code taken from that tutorial:


    <script type="text/javascript">
        function loadXMLDoc()
            var xmlhttp;
            if (window.XMLHttpRequest)
              // Code for Internet Explorer 7+, Firefox, Chrome, Opera, and Safari
              xmlhttp = new XMLHttpRequest();
                // Code for Internet Explorer 6 and Internet Explorer 5
                xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
                if (xmlhttp.readyState==4 && xmlhttp.status==200)
                    document.getElementById("myDiv").innerHTML = xmlhttp.responseText;
  "GET", "ajax_info.txt", true);

    <div id="myDiv"><h2>Let AJAX change this text</h2></div>
    <button type="button" onclick="loadXMLDoc()">Change Content</button>


How to find value using key in javascript dictionary

Arrays in JavaScript don't use strings as keys. You will probably find that the value is there, but the key is an integer.

If you make Dict into an object, this will work:

var dict = {};
var addPair = function (myKey, myValue) {
    dict[myKey] = myValue;
var giveValue = function (myKey) {
    return dict[myKey];

The myKey variable is already a string, so you don't need more quotes.

Passing arguments to require (when loading module)

Yes. In your login module, just export a single function that takes the db as its argument. For example:

module.exports = function(db) {

Event handler not working on dynamic content

You are missing the selector in the .on function:

.on(eventType, selector, function)

This selector is very important!

If new HTML is being injected into the page, select the elements and attach event handlers after the new HTML is placed into the page. Or, use delegated events to attach an event handler

See jQuery 1.9 .live() is not a function for more details.

Git push error: "origin does not appear to be a git repository"

I had this problem cause i had already origin remote defined locally. So just change "origin" into another name:

git remote add originNew

git push -u originNew

or u can remove your local origin. to check your remote name type:

git remote

to remove remote - log in your clone repository and type:

git remote remove origin(depending on your remote's name)

How do I serialize an object and save it to a file in Android?

I use SharePrefrences:

package myapps.serializedemo;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {

//Create the SharedPreferences
    SharedPreferences sharedPreferences = this.getSharedPreferences("myapps.serilizerdemo", Context.MODE_PRIVATE);
    ArrayList<String> friends = new ArrayList<>();
    try {

 //Write / Serialize
    } catch (IOException e) {
    ArrayList<String> newFriends = new ArrayList<>();
    try {
        newFriends = (ArrayList<String>) ObjectSerializer.deserialize(
                sharedPreferences.getString("friends", ObjectSerializer.serialize(new ArrayList<String>())));
    } catch (IOException e) {
    Log.i("***NewFriends", newFriends.toString());

Resize jqGrid when browser is resized?

I'm using for layout so my solution is as follows:

        function() {
                    //  Grid ids we are using
            $("#demogr, #allergygr, #problemsgr, #diagnosesgr, #medicalhisgr").setGridWidth(
            $("#clinteamgr, #procedgr").setGridWidth(
// Here we set a global options

jQuery.extend(jQuery.jgrid.defaults, {
    // altRows:true,
    autowidth : true,
    beforeSelectRow : function(rowid, e) { // disable row highlighting onclick
        return false;
    datatype : "jsonstring",
    datastr : grdata,  //  JSON object generated by another function
    gridview : false,
    height : '100%',
    hoverrows : false,
    loadonce : true,
    sortable : false,
    jsonReader : {
        repeatitems : false

// Demographics Grid

$("#demogr").jqGrid( {
    caption : "Demographics",
    colNames : [ 'Info', 'Data' ],
    colModel : [ {
        name : 'Info',
        width : "30%",
        sortable : false,
        jsonmap : 'ITEM'
    }, {
        name : 'Description',
        width : "70%",
        sortable : false,
        jsonmap : 'DESCRIPTION'
    } ],
    jsonReader : {
        root : "DEMOGRAPHICS",
        id : "DEMOID"

// Other grids defined below...

maven command line how to point to a specific settings.xml for a single command?

You can simply use:

mvn --settings YourOwnSettings.xml clean install


mvn -s YourOwnSettings.xml clean install

How to open mail app from Swift

You can use simple mailto: links in iOS to open the mail app.

let email = "[email protected]"
if let url = URL(string: "mailto:\(email)") {
  if #available(iOS 10.0, *) {
  } else {

Shell Script: How to write a string to file and to stdout on console?

You can use >> to print in another file.

echo "hello" >> logfile.txt

JavaScript post request like a form submit

Dynamically create <input>s in a form and submit it

 * sends a request to the specified url from a form. this will change the window location.
 * @param {string} path the path to send the post request to
 * @param {object} params the paramiters to add to the url
 * @param {string} [method=post] the method to use on the form

function post(path, params, method='post') {

  // The rest of this code assumes you are not using a library.
  // It can be made less wordy if you use one.
  const form = document.createElement('form');
  form.method = method;
  form.action = path;

  for (const key in params) {
    if (params.hasOwnProperty(key)) {
      const hiddenField = document.createElement('input');
      hiddenField.type = 'hidden'; = key;
      hiddenField.value = params[key];




post('/contact/', {name: 'Johnny Bravo'});

EDIT: Since this has gotten upvoted so much, I'm guessing people will be copy-pasting this a lot. So I added the hasOwnProperty check to fix any inadvertent bugs.

Importing images from a directory (Python) to list or dictionary

I'd start by using glob:

from PIL import Image
import glob
image_list = []
for filename in glob.glob('yourpath/*.gif'): #assuming gif

then do what you need to do with your list of images (image_list).

How do I change the number of open files limit in Linux?

1) Add the following line to /etc/security/limits.conf

webuser hard nofile 64000

then login as webuser

su - webuser

2) Edit following two files for webuser

append .bashrc and .bash_profile file by running

echo "ulimit -n 64000" >> .bashrc ; echo "ulimit -n 64000" >> .bash_profile

3) Log out, then log back in and verify that the changes have been made correctly:

$ ulimit -a | grep open
open files                      (-n) 64000

Thats it and them boom, boom boom.

getApplication() vs. getApplicationContext()

It seems to have to do with context wrapping. Most classes derived from Context are actually a ContextWrapper, which essentially delegates to another context, possibly with changes by the wrapper.

The context is a general abstraction that supports mocking and proxying. Since many contexts are bound to a limited-lifetime object such as an Activity, there needs to be a way to get a longer-lived context, for purposes such as registering for future notifications. That is achieved by Context.getApplicationContext(). A logical implementation is to return the global Application object, but nothing prevents a context implementation from returning a wrapper or proxy with a suitable lifetime instead.

Activities and services are more specifically associated with an Application object. The usefulness of this, I believe, is that you can create and register in the manifest a custom class derived from Application and be certain that Activity.getApplication() or Service.getApplication() will return that specific object of that specific type, which you can cast to your derived Application class and use for whatever custom purpose.

In other words, getApplication() is guaranteed to return an Application object, while getApplicationContext() is free to return a proxy instead.

SQL Server IIF vs CASE

IIF is a non-standard T-SQL function. It was added to SQL SERVER 2012, so that Access could migrate to SQL Server without refactoring the IIF's to CASE before hand. Once the Access db is fully migrated into SQL Server, you can refactor.

Partial Dependency (Databases)

A FD (functional dependency) that holds in a relation is partial when removing one of the determining attributes gives a FD that holds in the relation. A FD that isn't partial is full.

Eg: If {A,B} ? {C} but also {A} ? {C} then {C} is partially functionally dependent on {A,B}.

Eg: Here's a relation value where that example condition holds. (A FD holds in a relation variable when it holds in every value that can arise.)

A  B  C
1  1  1
1  2  1
2  1  1

The non-trivial FDs that hold: {A,B} determines {C}, {B,C}, {A,C} & {A,B,C}; {A}, {B} & {} also determine {C}. Of those: {A,B} ? {C} is partial per {A} ? {C}, {B} ? {C} & {} ? {C}; {A} ? {C} & {B} ? {C} are partial per {} ? {C}; the others are full.

A functional dependency X ? Y is a full functional dependency if removal of any attribute A from X means that the dependency does not hold any more; that is, for any attribute A e X, (X – {A}) does not functionally determine Y. A functional dependency X ? Y is a partial dependency if some attribute A e X can be removed from X and the dependency still holds; that is, for some A e X, (X – {A}) ? Y.

-- FUNDAMENTALS OF Database Systems SIXTH EDITION Ramez Elmasri & Navathe

Notice that whether a FD is full vs partial doesn't depend on CKs (candidate keys), let alone one CK that you might be calling the PK (primary key).

(A definition of 2NF is that every non-CK attribute is fully functionally determined by every CK. Observe that the only CK is {A,B} & the only non-CK attribute C is partially dependent on it so this value is not in 2NF & indeed it is the lossless join of components/projections onto {A,B} & {A,C}, onto {A,B} & {B,C} & onto {A,B} & {C}.)

(Beware that that textbook's definition of "transitive FD" does not define the same sort of thing as the standard definition of "transitive FD".)

How to capitalize first letter of each word, like a 2-word city?

You can use CSS:

p.capitalize {text-transform:capitalize;}

Update (JS Solution):

Based on Kamal Reddy's comment:

document.getElementById("myP").style.textTransform = "capitalize";

How do I use DateTime.TryParse with a Nullable<DateTime>?

What about creating an extension method?

public static class NullableExtensions
    public static bool TryParse(this DateTime? dateTime, string dateString, out DateTime? result)
        DateTime tempDate;
        if(! DateTime.TryParse(dateString,out tempDate))
            result = null;
            return false;

        result = tempDate;
        return true;


Visual Studio Code Tab Key does not insert a tab

In, my case I followed this advice and changed this emmet setting in vscode to false:

"emmet.triggerExpansionOnTab": false

I was receinving the error Cannot read property 'value' of null. It solved the problem immediatelly.

Groovy method with optional parameters

You can use arguments with default values.

def someMethod(def mandatory,def optional=null){}

if argument "optional" not exist, it turns to "null".

Meaning of Open hashing and Closed hashing

The name open addressing refers to the fact that the location ("address") of the element is not determined by its hash value. (This method is also called closed hashing).

In separate chaining, each bucket is independent, and has some sort of ADT (list, binary search trees, etc) of entries with the same index. In a good hash table, each bucket has zero or one entries, because we need operations of order O(1) for insert, search, etc.

This is a example of separate chaining using C++ with a simple hash function using mod operator (clearly, a bad hash function)

Find Number of CPUs and Cores per CPU using Command Prompt

In order to check the absence of physical sockets run:

wmic cpu get SocketDesignation

Path to MSBuild

easiest way might be to open PowerShell and enter

dir HKLM:\SOFTWARE\Microsoft\MSBuild\ToolsVersions\

How to focus on a form input text field on page load using jQuery?

Why is everybody using jQuery for something simple as this.

<body OnLoad="document.myform.mytextfield.focus();">

How can I select all elements without a given class in jQuery?

if (!$(row).hasClass("changed")) {
    // do your stuff

How to align iframe always in the center

If all you want to do is display an iframe on a page, the simplest solution I was able to come up with doesn't require divs or flex stuff is:

html {
    width: 100%;
    height: 100%;
    display: table;

body {
    text-align: center;
    vertical-align: middle;
    display: table-cell;

And then the HTML is just:

     <iframe ...></iframe>

If this is all you need you don't need wrapper divs to do it. This works for text content and stuff, too.


Also this looks even simpler.

Get Hours and Minutes (HH:MM) from date

Here is syntax for showing hours and minutes for a field coming out of a SELECT statement. In this example, the SQL field is named "UpdatedOnAt" and is a DateTime. Tested with MS SQL 2014.

SELECT Format(UpdatedOnAt ,'hh:mm') as UpdatedOnAt from MyTable

I like the format that shows the day of the week as a 3-letter abbreviation, and includes the seconds:

SELECT Format(UpdatedOnAt ,'ddd hh:mm:ss') as UpdatedOnAt from MyTable

The "as UpdatedOnAt" suffix is optional. It gives you a column heading equal tot he field you were selecting to begin with.

How to randomize two ArrayLists in the same fashion?

Wrap them in another class so that you can end up with a single array or List of those objects.

public class Data {
    private String txtFileName;
    private String imgFileName;

    // Add/generate c'tor, getter/setter, equals, hashCode and other boilerplate.

Usage example:

List<Data> list = new ArrayList<Data>();
list.add(new Data("H1.txt", "e1.jpg"));
list.add(new Data("H2.txt", "e2.jpg"));
// ...


Best way to track onchange as-you-type in input type="text"?

Javascript is unpredictable and funny here.

  • onchange occurs only when you blur the textbox
  • onkeyup & onkeypress doesn't always occur on text change
  • onkeydown occurs on text change (but cannot track cut & paste with mouse click)
  • onpaste & oncut occurs with keypress and even with the mouse right click.

So, to track the change in textbox, we need onkeydown, oncut and onpaste. In the callback of these event, if you check the value of the textbox then you don't get the updated value as the value is changed after the callback. So a solution for this is to set a timeout function with a timeout of 50 mili-seconds (or may be less) to track the change.

This is a dirty hack but this is the only way, as I researched.

Here is an example.

Is there a jQuery unfocus method?

So you can do this


try it and give feedback

Two models in one view in ASP MVC 3

If you are a fan of having very flat models, just to support the view, you should create a model specific to this particular view...

public class EditViewModel
    public int PersonID { get; set; }
    public string PersonName { get; set; }
    public int OrderID { get; set; }
    public int TotalSum { get; set; }

Many people use AutoMapper to map from their domain objects to their flat views.

The idea of the view model is that it just supports the view - nothing else. You have one per view to ensure that it only contains what is required for that view - not loads of properties that you want for other views.

How to get a matplotlib Axes instance to plot to?

Use the gca ("get current axes") helper function:

ax = plt.gca()


import matplotlib.pyplot as plt
quotes = [(1, 5, 6, 7, 4), (2, 6, 9, 9, 6), (3, 9, 8, 10, 8), (4, 8, 8, 9, 8), (5, 8, 11, 13, 7)]
ax = plt.gca()
h =, quotes)

enter image description here

How do you save/store objects in SharedPreferences on Android?

An other way to save and restore an object from android sharedpreferences without using the Json format

private static ExampleObject getObject(Context c,String db_name){
            SharedPreferences sharedPreferences = c.getSharedPreferences(db_name, Context.MODE_PRIVATE);
            ExampleObject o = new ExampleObject();
            Field[] fields = o.getClass().getFields();
            try {
                for (Field field : fields) {
                    Class<?> type = field.getType();
                    try {
                        final String name = field.getName();
                        if (type == Character.TYPE || type.equals(String.class)) {
                            field.set(o,sharedPreferences.getString(name, ""));
                        } else if (type.equals(int.class) || type.equals(Short.class))
                            field.setInt(o,sharedPreferences.getInt(name, 0));
                        else if (type.equals(double.class))
                            field.setDouble(o,sharedPreferences.getFloat(name, 0));
                        else if (type.equals(float.class))
                            field.setFloat(o,sharedPreferences.getFloat(name, 0));
                        else if (type.equals(long.class))
                            field.setLong(o,sharedPreferences.getLong(name, 0));
                        else if (type.equals(Boolean.class))
                            field.setBoolean(o,sharedPreferences.getBoolean(name, false));
                        else if (type.equals(UUID.class))

                    } catch (IllegalAccessException e) {
                        Log.e(StaticConfig.app_name, "IllegalAccessException", e);
                    } catch (IllegalArgumentException e) {
                        Log.e(StaticConfig.app_name, "IllegalArgumentException", e);
            } catch (Exception e) {
                System.out.println("Exception: " + e);
            return o;
        private static void setObject(Context context, Object o, String db_name) {
            Field[] fields = o.getClass().getFields();
            SharedPreferences sp = context.getSharedPreferences(db_name, Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = sp.edit();
            for (Field field : fields) {
                Class<?> type = field.getType();
                try {
                    final String name = field.getName();
                    if (type == Character.TYPE || type.equals(String.class)) {
                        Object value = field.get(o);
                        if (value != null)
                            editor.putString(name, value.toString());
                    } else if (type.equals(int.class) || type.equals(Short.class))
                        editor.putInt(name, field.getInt(o));
                    else if (type.equals(double.class))
                        editor.putFloat(name, (float) field.getDouble(o));
                    else if (type.equals(float.class))
                        editor.putFloat(name, field.getFloat(o));
                    else if (type.equals(long.class))
                        editor.putLong(name, field.getLong(o));
                    else if (type.equals(Boolean.class))
                        editor.putBoolean(name, field.getBoolean(o));
                    else if (type.equals(UUID.class))
                        editor.putString(name, field.get(o).toString());

                } catch (IllegalAccessException e) {
                    Log.e(StaticConfig.app_name, "IllegalAccessException", e);
                } catch (IllegalArgumentException e) {
                    Log.e(StaticConfig.app_name, "IllegalArgumentException", e);


Javascript get the text value of a column from a particular row of an html table

in case if your table has tbody

let tbl = document.getElementById("tbl").getElementsByTagName('tbody')[0];

Custom alert and confirm box in jquery

Try using SweetAlert its just simply the best . You will get a lot of customization and flexibility.

Confirm Example

    title: "Are you sure?",
    text: "You will not be able to recover this imaginary file!",
    type: "warning",   
    showCancelButton: true,   
    confirmButtonColor: "#DD6B55",
    confirmButtonText: "Yes, delete it!"

Sample Alert