SyntaxFix

Programs & Examples On #Graphml

File-format for graphs which consists of a language core to describe the structural properties of a graph and a flexible extension mechanism to add application-specific data

How to get coordinates of an svg element?

The way to determine the coordinates depends on what element you're working with. For circles for example, the cx and cy attributes determine the center position. In addition, you may have a translation applied through the transform attribute which changes the reference point of any coordinates.

Most of the ways used in general to get screen coordinates won't work for SVGs. In addition, you may not want absolute coordinates if the line you want to draw is in the same container as the elements it connects.

Edit:

In your particular code, it's quite difficult to get the position of the node because its determined by a translation of the parent element. So you need to get the transform attribute of the parent node and extract the translation from that.

d3.transform(d3.select(this.parentNode).attr("transform")).translate

Working jsfiddle here.

C++, copy set to vector

You haven't reserved enough space in your vector object to hold the contents of your set.

std::vector<double> output(input.size());
std::copy(input.begin(), input.end(), output.begin());

How to pull specific directory with git

For all that struggle with theoretical file paths and examples like I did, here a real world example: Microsoft offers their docs and examples on git hub, unfortunately they do gather all their example files for a large amount of topics in this repository:

https://github.com/microsoftarchive/msdn-code-gallery-community-s-z

I only was interested in the Microsoft Dynamics js files in the path

msdn-code-gallery-community-s-z/Sdk.Soap.js/

so I did the following

create a 

msdn-code-gallery-community-s-zSdkSoapjs\.git\info\sparse-checkout

file in my repositories folder on the disk

git sparse-checkout init

in that directory using cmd on windows

The file contents of 

msdn-code-gallery-community-s-zSdkSoapjs\.git\info\sparse-checkout

is 

Sdk.Soap.js/*

finally do a 

git pull origin master

PHP array delete by value (not key)

Well, deleting an element from array is basically just set difference with one element.

array_diff( [312, 401, 15, 401, 3], [401] ) // removing 401 returns [312, 15, 3]

It generalizes nicely, you can remove as many elements as you like at the same time, if you want.

Disclaimer: Note that my solution produces a new copy of the array while keeping the old one intact in contrast to the accepted answer which mutates. Pick the one you need.

Matching an empty input box using CSS

If supporting legacy browsers is not needed, you could use a combination of required, valid, and invalid.

The good thing about using this is the valid and invalid pseudo-elements work well with the type attributes of input fields. For example:

_x000D_
_x000D_ 
input:invalid, textarea:invalid { _x000D_
    box-shadow: 0 0 5px #d45252;_x000D_
    border-color: #b03535_x000D_
}_x000D_
_x000D_
input:valid, textarea:valid {_x000D_
    box-shadow: 0 0 5px #5cd053;_x000D_
    border-color: #28921f;_x000D_
}
_x000D_ 
<input type="email" name="email" placeholder="[email protected]" required />_x000D_
<input type="url" name="website" placeholder="http://johndoe.com"/>_x000D_
<input type="text" name="name" placeholder="John Doe" required/>
_x000D_
_x000D_
_x000D_

For reference, JSFiddle here: http://jsfiddle.net/0sf6m46j/

How to align a <div> to the middle (horizontally/width) of the page

To make it also work correctly in Internet Explorer 6 you have to do it as follows:

HTML

<body>
    <div class="centered">
        centered content
    </div>
</body>

CSS

body {
    margin: 0;
    padding: 0;
    text-align: center; /* !!! */
}

.centered {
    margin: 0 auto;
    text-align: left;
    width: 800px;
}

Edit a specific Line of a Text File in C#

You can't rewrite a line without rewriting the entire file (unless the lines happen to be the same length). If your files are small then reading the entire target file into memory and then writing it out again might make sense. You can do that like this:

using System;
using System.IO;

class Program
{
    static void Main(string[] args)
    {
        int line_to_edit = 2; // Warning: 1-based indexing!
        string sourceFile = "source.txt";
        string destinationFile = "target.txt";

        // Read the appropriate line from the file.
        string lineToWrite = null;
        using (StreamReader reader = new StreamReader(sourceFile))
        {
            for (int i = 1; i <= line_to_edit; ++i)
                lineToWrite = reader.ReadLine();
        }

        if (lineToWrite == null)
            throw new InvalidDataException("Line does not exist in " + sourceFile);

        // Read the old file.
        string[] lines = File.ReadAllLines(destinationFile);

        // Write the new file over the old file.
        using (StreamWriter writer = new StreamWriter(destinationFile))
        {
            for (int currentLine = 1; currentLine <= lines.Length; ++currentLine)
            {
                if (currentLine == line_to_edit)
                {
                    writer.WriteLine(lineToWrite);
                }
                else
                {
                    writer.WriteLine(lines[currentLine - 1]);
                }
            }
        }
    }
}

If your files are large it would be better to create a new file so that you can read streaming from one file while you write to the other. This means that you don't need to have the whole file in memory at once. You can do that like this:

using System;
using System.IO;

class Program
{
    static void Main(string[] args)
    {
        int line_to_edit = 2;
        string sourceFile = "source.txt";
        string destinationFile = "target.txt";
        string tempFile = "target2.txt";

        // Read the appropriate line from the file.
        string lineToWrite = null;
        using (StreamReader reader = new StreamReader(sourceFile))
        {
            for (int i = 1; i <= line_to_edit; ++i)
                lineToWrite = reader.ReadLine();
        }

        if (lineToWrite == null)
            throw new InvalidDataException("Line does not exist in " + sourceFile);

        // Read from the target file and write to a new file.
        int line_number = 1;
        string line = null;
        using (StreamReader reader = new StreamReader(destinationFile))
        using (StreamWriter writer = new StreamWriter(tempFile))
        {
            while ((line = reader.ReadLine()) != null)
            {
                if (line_number == line_to_edit)
                {
                    writer.WriteLine(lineToWrite);
                }
                else
                {
                    writer.WriteLine(line);
                }
                line_number++;
            }
        }

        // TODO: Delete the old file and replace it with the new file here.
    }
}

You can afterwards move the file once you are sure that the write operation has succeeded (no excecption was thrown and the writer is closed).

Note that in both cases it is a bit confusing that you are using 1-based indexing for your line numbers. It might make more sense in your code to use 0-based indexing. You can have 1-based index in your user interface to your program if you wish, but convert it to a 0-indexed before sending it further.

Also, a disadvantage of directly overwriting the old file with the new file is that if it fails halfway through then you might permanently lose whatever data wasn't written. By writing to a third file first you only delete the original data after you are sure that you have another (corrected) copy of it, so you can recover the data if the computer crashes halfway through.

A final remark: I noticed that your files had an xml extension. You might want to consider if it makes more sense for you to use an XML parser to modify the contents of the files instead of replacing specific lines.

Change URL and redirect using jQuery

Try this...

$("#abc").attr("action", "/yourapp/" + temp).submit();

What it means:

Find a form with id "abc", change it's attribute named "action" and then submit it...

This works for me... !!!

Is there any WinSCP equivalent for linux?
  1. gFTP
  2. Konqueror's fish kio-slave (just write as file path: ssh://user@server/path

Apache Spark: The number of cores vs. the number of executors

There is a small issue in the First two configurations i think. The concepts of threads and cores like follows. The concept of threading is if the cores are ideal then use that core to process the data. So the memory is not fully utilized in first two cases. If you want to bench mark this example choose the machines which has more than 10 cores on each machine. Then do the bench mark.

But dont give more than 5 cores per executor there will be bottle neck on i/o performance.

So the best machines to do this bench marking might be data nodes which have 10 cores.

Data node machine spec: CPU: Core i7-4790 (# of cores: 10, # of threads: 20) RAM: 32GB (8GB x 4) HDD: 8TB (2TB x 4)

MySQL: Large VARCHAR vs. TEXT?

Just to clarify the best practice:

  1. Text format messages should almost always be stored as TEXT (they end up being arbitrarily long)

  2. String attributes should be stored as VARCHAR (the destination user name, the subject, etc...).

I understand that you've got a front end limit, which is great until it isn't. *grin* The trick is to think of the DB as separate from the applications that connect to it. Just because one application puts a limit on the data, doesn't mean that the data is intrinsically limited.

What is it about the messages themselves that forces them to never be more then 3000 characters? If it's just an arbitrary application constraint (say, for a text box or something), use a TEXT field at the data layer.

How to delete parent element using jQuery

Use parents() instead of parent():

$("a").click(function(event) {
  event.preventDefault();
  $(this).parents('.li').remove();
});

How to use a servlet filter in Java to change an incoming servlet request url?
  1. Implement javax.servlet.Filter.
  2. In doFilter() method, cast the incoming ServletRequest to HttpServletRequest.
  3. Use HttpServletRequest#getRequestURI() to grab the path.
  4. Use straightforward java.lang.String methods like substring(), split(), concat() and so on to extract the part of interest and compose the new path.
  5. Use either ServletRequest#getRequestDispatcher() and then RequestDispatcher#forward() to forward the request/response to the new URL (server-side redirect, not reflected in browser address bar), or cast the incoming ServletResponse to HttpServletResponse and then HttpServletResponse#sendRedirect() to redirect the response to the new URL (client side redirect, reflected in browser address bar).
  6. Register the filter in web.xml on an url-pattern of /* or /Check_License/*, depending on the context path, or if you're on Servlet 3.0 already, use the @WebFilter annotation for that instead.

Don't forget to add a check in the code if the URL needs to be changed and if not, then just call FilterChain#doFilter(), else it will call itself in an infinite loop.

Alternatively you can also just use an existing 3rd party API to do all the work for you, such as Tuckey's UrlRewriteFilter which can be configured the way as you would do with Apache's mod_rewrite.

How to watch and compile all TypeScript sources?

Today I designed this Ant MacroDef for the same problem as yours :

    <!--
    Recursively read a source directory for TypeScript files, generate a compile list in the
    format needed by the TypeScript compiler adding every parameters it take.
-->
<macrodef name="TypeScriptCompileDir">

    <!-- required attribute -->
    <attribute name="src" />

    <!-- optional attributes -->
    <attribute name="out" default="" />
    <attribute name="module" default="" />
    <attribute name="comments" default="" />
    <attribute name="declarations" default="" />
    <attribute name="nolib" default="" />
    <attribute name="target" default="" />

    <sequential>

        <!-- local properties -->
        <local name="out.arg"/>
        <local name="module.arg"/>
        <local name="comments.arg"/>
        <local name="declarations.arg"/>
        <local name="nolib.arg"/>
        <local name="target.arg"/>
        <local name="typescript.file.list"/>
        <local name="tsc.compile.file"/>

        <property name="tsc.compile.file" value="@{src}compile.list" />

        <!-- Optional arguments are not written to compile file when attributes not set -->
        <condition property="out.arg" value="" else='--out "@{out}"'>
            <equals arg1="@{out}" arg2="" />
        </condition>

        <condition property="module.arg" value="" else="--module @{module}">
            <equals arg1="@{module}" arg2="" />
        </condition>

        <condition property="comments.arg" value="" else="--comments">
            <equals arg1="@{comments}" arg2="" />
        </condition>

        <condition property="declarations.arg" value="" else="--declarations">
            <equals arg1="@{declarations}" arg2="" />
        </condition>

        <condition property="nolib.arg" value="" else="--nolib">
            <equals arg1="@{nolib}" arg2="" />
        </condition>

        <!-- Could have been defaulted to ES3 but let the compiler uses its own default is quite better -->
        <condition property="target.arg" value="" else="--target @{target}">
            <equals arg1="@{target}" arg2="" />
        </condition>

        <!-- Recursively read TypeScript source directory and generate a compile list -->
        <pathconvert property="typescript.file.list" dirsep="\" pathsep="${line.separator}">

            <fileset dir="@{src}">
                <include name="**/*.ts" />
            </fileset>

            <!-- In case regexp doesn't work on your computer, comment <mapper /> and uncomment <regexpmapper /> -->
            <mapper type="regexp" from="^(.*)$" to='"\1"' />
            <!--regexpmapper from="^(.*)$" to='"\1"' /-->

        </pathconvert>


        <!-- Write to the file -->
        <echo message="Writing tsc command line arguments to : ${tsc.compile.file}" />
        <echo file="${tsc.compile.file}" message="${typescript.file.list}${line.separator}${out.arg}${line.separator}${module.arg}${line.separator}${comments.arg}${line.separator}${declarations.arg}${line.separator}${nolib.arg}${line.separator}${target.arg}" append="false" />

        <!-- Compile using the generated compile file -->
        <echo message="Calling ${typescript.compiler.path} with ${tsc.compile.file}" />
        <exec dir="@{src}" executable="${typescript.compiler.path}">
            <arg value="@${tsc.compile.file}"/>
        </exec>

        <!-- Finally delete the compile file -->
        <echo message="${tsc.compile.file} deleted" />
        <delete file="${tsc.compile.file}" />

    </sequential>

</macrodef>

Use it in your build file with :

    <!-- Compile a single JavaScript file in the bin dir for release -->
    <TypeScriptCompileDir
        src="${src-js.dir}"
        out="${release-file-path}"
        module="amd"
    />

It is used in the project PureMVC for TypeScript I'm working on at the time using Webstorm.

Remove element from JSON Object

To iterate through the keys of an object, use a for .. in loop:

for (var key in json_obj) {
    if (json_obj.hasOwnProperty(key)) {
        // do something with `key'
    }
}

To test all elements for empty children, you can use a recursive approach: iterate through all elements and recursively test their children too.

Removing a property of an object can be done by using the delete keyword:

var someObj = {
    "one": 123,
    "two": 345
};
var key = "one";
delete someObj[key];
console.log(someObj); // prints { "two": 345 }

Documentation:

Installing PG gem on OS X - failure to build native extension

If you are using Ubuntu try to install following lib file

sudo apt-get install libpq-dev

and then

gem install pg

worked for me.

svn list of files that are modified in local copy

Using Powershell you can do this:

# Checks for updates and changes in working copy.
# Regex: Excludes unmodified (first 7 columns blank). To exclude more add criteria to negative look ahead.
# -u: svn gets updates
$regex = '^(?!\s{7}).{7}\s+(.+)';
svn status -u | %{ if($_ -match $regex){ $_ } };

This will include property changes. These show in column 2. It will also catch other differences in files that show in columns 3-7.

Sources:

What would be the best method to code heading/title for <ul> or <ol>, Like we have <caption> in <table>?

how about making the heading a list-element with different styles like so

<ul>
 <li class="heading">heading</li>
 <li>list item</li>
 <li>list item</li>
 <li>list item</li>
 <li>list item</li>
</ul>

and the CSS

ul .heading {font-weight: normal; list-style: none;}

additionally, use a reset CSS to set margins and paddings right on the ul and li. here's a good reset CSS. once you've reset the margins and paddings, you can apply some margin on the list-elements other than the one's with the heading class, to indent them.

How to disable/enable a button with a checkbox if checked

HTML

<input type="checkbox" id="checkme"/><input type="submit" name="sendNewSms" class="inputButton" id="sendNewSms" value=" Send " />

JS

var checker = document.getElementById('checkme');
var sendbtn = document.getElementById('sendNewSms');
checker.onchange = function() {
  sendbtn.disabled = !!this.checked;
};

DEMO

SVN Commit specific files

Due to my subversion state, I had to get creative. svn st showed M,A and ~ statuses. I only wanted M and A so...

svn st | grep ^[A\|M] | cut -d' ' -f8- > targets.txt

This command says find all the lines output by svn st that start with M or A, cut using space delimiter, then get colums 8 to the end. Dump that into targets.txt and overwrite.

Then modify targets.txt to prune the file list further. Then run below to commit:

svn ci -m "My commit message" --targets targets.txt

Probably not the most common use case, but hopefully it helps someone.

How to suppress "error TS2533: Object is possibly 'null' or 'undefined'"?

This is not the OP's problem, but I got the same Object is possibly 'null' message when I had declared a parameter as the null type by accident:

something: null;

instead of assigning it the value of null:

something: string = null;

How to measure time elapsed on Javascript?

The Date documentation states that :

The JavaScript date is based on a time value that is milliseconds since midnight January 1, 1970, UTC

Click on start button then on end button. It will show you the number of seconds between the 2 clicks.

The milliseconds diff is in variable timeDiff. Play with it to find seconds/minutes/hours/ or what you need

_x000D_
_x000D_ 
var startTime, endTime;_x000D_
_x000D_
function start() {_x000D_
  startTime = new Date();_x000D_
};_x000D_
_x000D_
function end() {_x000D_
  endTime = new Date();_x000D_
  var timeDiff = endTime - startTime; //in ms_x000D_
  // strip the ms_x000D_
  timeDiff /= 1000;_x000D_
_x000D_
  // get seconds _x000D_
  var seconds = Math.round(timeDiff);_x000D_
  console.log(seconds + " seconds");_x000D_
}
_x000D_ 
<button onclick="start()">Start</button>_x000D_
_x000D_
<button onclick="end()">End</button>
_x000D_
_x000D_
_x000D_

OR another way of doing it for modern browser

Using performance.now() which returns a value representing the time elapsed since the time origin. This value is a double with microseconds in the fractional.

The time origin is a standard time which is considered to be the beginning of the current document's lifetime.

_x000D_
_x000D_ 
var startTime, endTime;_x000D_
_x000D_
function start() {_x000D_
  startTime = performance.now();_x000D_
};_x000D_
_x000D_
function end() {_x000D_
  endTime = performance.now();_x000D_
  var timeDiff = endTime - startTime; //in ms _x000D_
  // strip the ms _x000D_
  timeDiff /= 1000; _x000D_
  _x000D_
  // get seconds _x000D_
  var seconds = Math.round(timeDiff);_x000D_
  console.log(seconds + " seconds");_x000D_
}
_x000D_ 
<button onclick="start()">Start</button>_x000D_
<button onclick="end()">End</button>
_x000D_
_x000D_
_x000D_

Understanding the ngRepeat 'track by' expression

a short summary:

track by is used in order to link your data with the DOM generation (and mainly re-generation) made by ng-repeat.

when you add track by you basically tell angular to generate a single DOM element per data object in the given collection

this could be useful when paging and filtering, or any case where objects are added or removed from ng-repeat list.

usually, without track by angular will link the DOM objects with the collection by injecting an expando property - $$hashKey - into your JavaScript objects, and will regenerate it (and re-associate a DOM object) with every change.

full explanation:

http://www.bennadel.com/blog/2556-using-track-by-with-ngrepeat-in-angularjs-1-2.htm

a more practical guide:

http://www.codelord.net/2014/04/15/improving-ng-repeat-performance-with-track-by/

(track by is available in angular > 1.2 )

How to Apply Mask to Image in OpenCV?

Here is some code to apply binary mask on a video frame sequence acquired from a webcam. comment and uncomment the "bitwise_not(Mon_mask,Mon_mask);"line and see the effect.

bests, Ahmed.

#include "cv.h"      // include it to used Main OpenCV functions.
#include "highgui.h" //include it to use GUI functions.

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
    int c;

int radius=100;
      CvPoint2D32f center;
    //IplImage* color_img;
      Mat image, image0,image1; 
        IplImage *tmp;
    CvCapture* cv_cap = cvCaptureFromCAM(0);

    while(1)  {
        tmp = cvQueryFrame(cv_cap); // get frame
          // IplImage to Mat
            Mat imgMat(tmp);
            image =tmp; 



    center.x = tmp->width/2;
    center.y = tmp->height/2;

         Mat Mon_mask(image.size(), CV_8UC1, Scalar(0,0,0));


        circle(Mon_mask, center, radius, Scalar(255,255,255), -1, 8, 0 ); //-1 means filled

        bitwise_not(Mon_mask,Mon_mask);// commenté ou pas = RP ou DMLA 





        if(tmp != 0)

           imshow("Glaucom", image); // show frame

     c = cvWaitKey(10); // wait 10 ms or for key stroke
    if(c == 27)
        break; // if ESC, break and quit
    }
    /* clean up */
    cvReleaseCapture( &cv_cap );
    cvDestroyWindow("Glaucom");

}

Postgres ERROR: could not open file for reading: Permission denied

You must grant the pg_read_server_files permission to the user if you are not using postgres superuser.

Example:

GRANT pg_read_server_files TO my_user WITH ADMIN OPTION;

How to terminate a process in vbscript

 
Dim shll : Set shll = CreateObject("WScript.Shell")
Set Rt = shll.Exec("Notepad") : wscript.sleep 4000 : Rt.Terminate

Run the process with .Exec.

Then wait for 4 seconds.

After that kill this process.

How do I make a fully statically linked .exe with Visual Studio Express 2005?

In regards Jared's response, having Windows 2000 or better will not necessarily fix the issue at hand. Rob's response does work, however it is possible that this fix introduces security issues, as Windows updates will not be able to patch applications built as such.

In another post, Nick Guerrera suggests packaging the Visual C++ Runtime Redistributable with your applications, which installs quickly, and is independent of Visual Studio.

What does the colon (:) operator do?

colon is using in for-each loop, Try this example,

import java.util.*;

class ForEachLoop
{
       public static void main(String args[])
       {`enter code here`
       Integer[] iray={1,2,3,4,5};
       String[] sray={"ENRIQUE IGLESIAS"};
       printME(iray);
       printME(sray);

       }
       public static void printME(Integer[] i)
       {           
                  for(Integer x:i)
                  {
                    System.out.println(x);
                  }
       }
       public static void printME(String[] i)
       {
                   for(String x:i)
                   {
                   System.out.println(x);
                   }
       }
}

Characters allowed in GET parameter

From RFC 1738 on which characters are allowed in URLs:

Only alphanumerics, the special characters "$-_.+!*'(),", and reserved characters used for their reserved purposes may be used unencoded within a URL.

The reserved characters are ";", "/", "?", ":", "@", "=" and "&", which means you would need to URL encode them if you wish to use them.

java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlObject Error

I was working with talend V7.3.1 and I had poi version "4.1.0" and including xml-beans from the list of dependencies didnt fix my problem (i.e: 2.3.0 and 2.6.0).

It was fixed by downloading the jar "xmlbeans-3.0.1.jar" and adding it to the project

enter image description here

asp.net: Invalid postback or callback argument

if you change UseSubmitBehavior="True" to UseSubmitBehavior="False" your problem will be solved.

<asp:Button ID="BtnDis" runat="server" CommandName="BtnDis" CommandArgument='<%#Eval("Id")%>' Text="Discription" CausesValidation="True" UseSubmitBehavior="False" />

how to call a method in another Activity from Activity

The startActivityForResult pattern is much better suited for what you're trying to achieve : http://developer.android.com/reference/android/app/Activity.html#StartingActivities

Try below code

public class MainActivity extends Activity {  

    Button button1;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        textView1=(TextView)findViewById(R.id.textView1);  
        button1=(Button)findViewById(R.id.button1);  
        button1.setOnClickListener(new OnClickListener() {  
            @Override  
            public void onClick(View arg0) {  
                Intent intent=new Intent(MainActivity.this,SecondActivity.class);  
                startActivityForResult(intent, 2);// Activity is started with requestCode 2  
            }  
        });  
    }  
 // Call Back method  to get the Message form other Activity  
    @Override  
       protected void onActivityResult(int requestCode, int resultCode, Intent data)  
       {  
                 super.onActivityResult(requestCode, resultCode, data);  
                  // check if the request code is same as what is passed  here it is 2  
                   if(requestCode==2)  
                         {  
                          //do the things u wanted 
                         }  
     }  

}

SecondActivity.class

public class SecondActivity extends Activity {  

    Button button1;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_second);  

            button1=(Button)findViewById(R.id.button1);  
            button1.setOnClickListener(new OnClickListener() {  
                @Override  
                public void onClick(View arg0) {  
                    String message="hello ";  
                    Intent intent=new Intent();  
                    intent.putExtra("MESSAGE",message);  
                    setResult(2,intent);  
                    finish();//finishing activity  
                }  
            });  
    }  

}

Let me know if it helped...

What is a PDB file?

I had originally asked myself the question "Do I need a PDB file deployed to my customer's machine?", and after reading this post, decided to exclude the file.

Everything worked fine, until today, when I was trying to figure out why a message box containing an Exception.StackTrace was missing the file and line number information - necessary for troubleshooting the exception. I re-read this post and found the key nugget of information: that although the PDB is not necessary for the app to run, it is necessary for the file and line numbers to be present in the StackTrace string. I included the PDB file in the executable folder and now all is fine.

How to make child divs always fit inside parent div?

you could use display: inline-block;

hope it is useful.

AngularJS is rendering <br> as text not as a newline

You need to either use ng-bind-html-unsafe ... or you need to include the ngSanitize module and use ng-bind-html:

with ng-bind-html-unsafe

Use this if you trust the source of the HTML you're rendering it will render the raw output of whatever you put into it.

<div><h4>Categories</h4><span ng-bind-html-unsafe="q.CATEGORY"></span></div>

OR with ng-bind-html

Use this if you DON'T trust the source of the HTML (i.e. it's user input). It will sanitize the html to make sure it doesn't include things like script tags or other sources of potential security risks.

Make sure you include this:

<script src="http://code.angularjs.org/1.0.4/angular-sanitize.min.js"></script>

Then reference it in your application module:

var app = angular.module('myApp', ['ngSanitize']);

THEN use it:

<div><h4>Categories</h4><span ng-bind-html="q.CATEGORY"></span></div>

How to change font-size of a tag using inline css?

You should analyze your style.css file, possibly using Developer Tools in your favorite browser, to see which rule sets font size on the element in a manner that overrides the one in a style attribute. Apparently, it has to be one using the !important specifier, which generally indicates poor logic and structure in styling.

Primarily, modify the style.css file so that it does not use !important. Failing this, add !important to the rule in style attribute. But you should aim at reducing the use of !important, not increasing it.

Trimming text strings in SQL Server 2008

SQL Server does not have a TRIM function, but rather it has two. One each for specifically trimming spaces from the "front" of a string (LTRIM) and one for trimming spaces from the "end" of a string (RTRIM).

Something like the following will update every record in your table, trimming all extraneous space (either at the front or the end) of a varchar/nvarchar field:

UPDATE 
   [YourTableName]
SET
   [YourFieldName] = LTRIM(RTRIM([YourFieldName]))

(Strangely, SSIS (Sql Server Integration Services) does have a single TRIM function!)

How do I print bytes as hexadecimal?

Well you can convert one byte (unsigned char) at a time into a array like so

char buffer [17];
buffer[16] = 0;
for(j = 0; j < 8; j++)
    sprintf(&buffer[2*j], "%02X", data[j]);

Open Redis port for remote connections

For me, I needed to do the following:

1- Comment out bind 127.0.0.1

2- Change protected-mode to no

3- Protect my server with iptables (https://www.digitalocean.com/community/tutorials/how-to-implement-a-basic-firewall-template-with-iptables-on-ubuntu-14-04)

How to detect Adblock on my website?

Not a direct answer, but I'd put the message behind the ad to be loaded... rather that trying to detect it, it'd just show up when the ad doesn't.

IIS7 Cache-Control

Complementing Elmer's answer, as my edit was rolled back.

To cache static content for 365 days with public cache-control header, IIS can be configured with the following 

<staticContent>
    <clientCache cacheControlCustom="public" cacheControlMode="UseMaxAge" cacheControlMaxAge="365.00:00:00" />
</staticContent>

This will translate into a header like this:

Cache-Control: public,max-age=31536000

Note that max-age is a delta in seconds, being expressed by a positive 32bit integer as stated in RFC 2616 Sections 14.9.3 and 14.9.4. This represents a maximum value of 2^31 or 2,147,483,648 seconds (over 68 years). However, to better ensure compatibility between clients and servers, we adopt a recommended maximum of 365 days (one year).

As mentioned on other answers, you can use these directives also on the web.config of your site for all static content. As an alternative, you can use it only for contents in a specific location too (on the sample, 30 days public cache for contents in "cdn" folder):

<location path="cdn">
   <system.webServer>
        <staticContent>
             <clientCache cacheControlCustom="public" cacheControlMode="UseMaxAge" cacheControlMaxAge="30.00:00:00"/>
        </staticContent>
   </system.webServer>
</location>

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.

Git error: src refspec master does not match any error: failed to push some refs

It doesn't recognize that you have a master branch, but I found a way to get around it. I found out that there's nothing special about a master branch, you can just create another branch and call it master branch and that's what I did.

To create a master branch:

git checkout -b master

And you can work off of that.

How to stop a setTimeout loop?

SIMPLIEST WAY TO HANDLE TIMEOUT LOOP

function myFunc (terminator = false) {
    if(terminator) {
        clearTimeout(timeOutVar);
    } else {
        // do something
        timeOutVar = setTimeout(function(){myFunc();}, 1000);
    }
}   
myFunc(true); //  -> start loop
myFunc(false); //  -> end loop

Center Div inside another (100% width) div

The key is the margin: 0 auto; on the inner div. A proof-of-concept example:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<body>
    <div style="background-color: blue; width: 100%;">
        <div style="background-color: yellow; width: 940px; margin: 0 auto;">
            Test
        </div>
    </div>
</body>
</html>

I need to know how to get my program to output the word i typed in and also the new rearranged word using a 2D array
  1. What exactly doesn't work?
  2. Why are you using a 2d array?

  3. If you must use a 2d array:

    int numOfPairs = 10;  String[][] array = new String[numOfPairs][2]; for(int i = 0; i < array.length; i++){     for(int j = 0; j < array[i].length; j++){         array[i] = new String[2];         array[i][0] = "original word";         array[i][1] = "rearranged word";     }    }

Does this give you a hint?

PHP find difference between two datetimes

I'm not sure what format you're looking for in your difference but here's how to do it using DateTime

$datetime1 = new DateTime();
$datetime2 = new DateTime('2011-01-03 17:13:00');
$interval = $datetime1->diff($datetime2);
$elapsed = $interval->format('%y years %m months %a days %h hours %i minutes %s seconds');
echo $elapsed;

NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver

I just want to thank @Heapify for providing a practical answer and update his answer because the attached links are not up-to-date.

Step 1: Check the existing kernel of your Ubuntu Linux:

uname -a

Step 2:

Ubuntu maintains a website for all the versions of kernel that have been released. At the time of this writing, the latest stable release of Ubuntu kernel is 4.15. If you go to this link: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15/, you will see several links for download.

Step 3:

Download the appropriate files based on the type of OS you have. For 64 bit, I would download the following deb files:

// UP-TO-DATE 2019-03-18
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15/linux-headers-4.15.0-041500_4.15.0-041500.201802011154_all.deb
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15/linux-headers-4.15.0-041500-generic_4.15.0-041500.201802011154_amd64.deb
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15/linux-image-4.15.0-041500-generic_4.15.0-041500.201802011154_amd64.deb

Step 4:

Install all the downloaded deb files:

sudo dpkg -i *.deb

Step 5:

Reboot your machine and check if the kernel has been updated by:

uname -aenter code here

C++ compile error: has initializer but incomplete type

You need this include:

#include <sstream>

Read String line by line

You can use the stream api and a StringReader wrapped in a BufferedReader which got a lines() stream output in java 8:

import java.util.stream.*;
import java.io.*;
class test {
    public static void main(String... a) {
        String s = "this is a \nmultiline\rstring\r\nusing different newline styles";

        new BufferedReader(new StringReader(s)).lines().forEach(
            (line) -> System.out.println("one line of the string: " + line)
        );
    }
}

Gives

one line of the string: this is a
one line of the string: multiline
one line of the string: string
one line of the string: using different newline styles

Just like in BufferedReader's readLine, the newline character(s) themselves are not included. All kinds of newline separators are supported (in the same string even).

How to open local file on Jupyter?

Install jupyter. Open terminal. Go to folder where you file is (in terminal ie.cd path/to/folder). Run jupyter notebook. And voila: you have something like this:

enter image description here

Notice that to open a notebook in the folder, you can either click on it in the browser or go to address:

http://localhost:8888/notebooks/name_of_your_file.ipynb

Random word generator- Python

There is a package random_word could implement this request very conveniently:

 $ pip install random-word

from random_word import RandomWords
r = RandomWords()

# Return a single random word
r.get_random_word()
# Return list of Random words
r.get_random_words()
# Return Word of the day
r.word_of_the_day()

Setting default value for TypeScript object passed as argument

This can be a nice way to do it that does not involve long constructors

class Person {
    firstName?: string = 'Bob';
    lastName?: string = 'Smith';

    // Pass in this class as the required params
    constructor(params: Person) {
        // object.assign will overwrite defaults if params exist
        Object.assign(this, params)
    }
}

// you can still use the typing 
function sayName(params: Person){ 
    let name = params.firstName + params.lastName
    alert(name)
}

// you do have to call new but for my use case this felt better
sayName(new Person({firstName: 'Gordon'}))
sayName(new Person({lastName: 'Thomas'}))

Count a list of cells with the same background color

I just created this and it looks easier. You get these 2 functions:

=GetColorIndex(E5)  <- returns color number for the cell

from (cell)

=CountColorIndexInRange(C7:C24,14) <- returns count of cells C7:C24 with color 14

from (range of cells, color number you want to count)

example shows percent of cells with color 14

=ROUND(CountColorIndexInRange(C7:C24,14)/18, 4 )

Create these 2 VBA functions in a Module (hit Alt-F11)

open + folders. double-click on Module1

Just paste this text below in, then close the module window (it must save it then):

Function GetColorIndex(Cell As Range)
  GetColorIndex = Cell.Interior.ColorIndex
End Function

Function CountColorIndexInRange(Rng As Range, TestColor As Long)
  Dim cnt
  Dim cl As Range
  cnt = 0

  For Each cl In Rng
    If GetColorIndex(cl) = TestColor Then
      Rem Debug.Print ">" & TestColor & "<"
      cnt = cnt + 1
    End If
  Next

  CountColorIndexInRange = cnt

End Function

Jquery asp.net Button Click Event via ajax

I like Gromer's answer, but it leaves me with a question: What if I have multiple 'btnAwesome's in different controls?

To cater for that possibility, I would do the following:

$(document).ready(function() {
  $('#<%=myButton.ClientID %>').click(function() {
    // Do client side button click stuff here.
  });
});

It's not a regex match, but in my opinion, a regex match isn't what's needed here. If you're referencing a particular button, you want a precise text match such as this.

If, however, you want to do the same action for every btnAwesome, then go with Gromer's answer.

What is the difference between a function expression vs declaration in JavaScript?

Function Declaration

function foo() { ... }

Because of function hoisting, the function declared this way can be called both after and before the definition.

Function Expression

  1. Named Function Expression

    var foo = function bar() { ... }

  2. Anonymous Function Expression

    var foo = function() { ... }

foo() can be called only after creation.

Immediately-Invoked Function Expression (IIFE)

(function() { ... }());

Conclusion

Crockford recommends to use function expression because it makes it clear that foo is a variable containing a function value. Well, personally, I prefer to use Declaration unless there is a reason for Expression.

Merge or combine by rownames

you can wrap -Andrie answer into a generic function

mbind<-function(...){
 Reduce( function(x,y){cbind(x,y[match(row.names(x),row.names(y)),])}, list(...) )
}

Here, you can bind multiple frames with rownames as key

Differences between Octave and MATLAB?

Octave is basically an open source version of MATLAB. It was written to be just that. MATLAB has a very nice GUI which makes it a bit easier to use but the next stable release of OCTAVE will also have a GUI, which I have tested in the unstable release, and looks fantastic. Octave is much more buggy because it was developed and maintained by a group of volunteers, where the development of MATLAB is funded by millions of dollars by industry. I'm still a student and am using a student version of MATLAB, but I am thinking of going over to Octave once the stable version with the GUI is released.

MATLAB is probably a lot more powerful than Octave, and the algorithms run faster, but for most applications, Octave is more than adequate and is, in my opinion' an amazing tool that is completely free, where Octave is completely free.

I would say use MATLAB while you can use the academic version, but the switch to Octave should be seamless as they use the exact same syntax.

Lastly, there is the issue of SIMULINK. If you want to do simulation or control system design (there are probably a million other uses) SIMULINK is fantastic and comes with MATLAB. I don't think any other comes close to this, although Scilab is apparently a 'good' open source alternative, I haven't tried it.

Peace.

Integer division: How do you produce a double?

Best way to do this is

int i = 3;
Double d = i * 1.0;

d is 3.0 now.

Error:com.android.tools.aapt2.Aapt2Exception: AAPT2 error: check logs for details

I got same error AAPT2 error: check logs for details, and i applied above solutions, as per most common solution, i was opened gradle.properties and add line

android.enableAapt2=false

for solution, but i got an error Process 'command 'D:\Android\sdk\Sdk\build-tools\27.0.3\aapt.exe'' finished with non-zero exit value 1

But after many searches i found that there is problem in layout's xml file that i was repeat lines in layout's xml file which is as below:

xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"

Remove Repeat lines from xml file and rebuild project and Done.

java.net.MalformedURLException: no protocol on URL based on a string modified with URLEncoder

You need to encode your parameter's values before concatenating them to URL.
Backslash \ is special character which have to be escaped as %5C

Escaping example:

String paramValue = "param\\with\\backslash";
String yourURLStr = "http://host.com?param=" + java.net.URLEncoder.encode(paramValue, "UTF-8");
java.net.URL url = new java.net.URL(yourURLStr);

The result is http://host.com?param=param%5Cwith%5Cbackslash which is properly formatted url string.

How do you Make A Repeat-Until Loop in C++?

When you want to check the condition at the beginning of the loop, simply negate the condition on a standard while loop:

while(!cond) { ... }

If you need it at the end, use a do ... while loop and negate the condition:

do { ... } while(!cond);

Can I set an unlimited length for maxJsonLength in web.config?

NOTE: this answer applies only to Web services, if you are returning JSON from a Controller method, make sure you read this SO answer below as well: https://stackoverflow.com/a/7207539/1246870

The MaxJsonLength property cannot be unlimited, is an integer property that defaults to 102400 (100k).

You can set the MaxJsonLength property on your web.config:

<configuration> 
   <system.web.extensions>
       <scripting>
           <webServices>
               <jsonSerialization maxJsonLength="50000000"/>
           </webServices>
       </scripting>
   </system.web.extensions>
</configuration>

ImportError: cannot import name NUMPY_MKL

Reinstall numpy-1.11.0_XXX.whl (for your Python) from www.lfd.uci.edu/~gohlke/pythonlibs. This file has the same name and version if compare with the variant downloaded by me earlier 29.03.2016, but its size and content differ from old variant. After re-installation error disappeared.

Second option - return back to scipy 0.17.0 from 0.17.1

P.S. I use Windows 64-bit version of Python 3.5.1, so can't guarantee that numpy for Python 2.7 is already corrected.

How to get height and width of device display in angular2 using typescript?

Keep in mind if you are wanting to test this component you will want to inject the window. Use the @Inject() function to inject the window object by naming it using a string token like detailed in this duplicate

"git pull" or "git merge" between master and development branches

my rule of thumb is:

rebase for branches with the same name, merge otherwise.

examples for same names would be master, origin/master and otherRemote/master.

if develop exists only in the local repository, and it is always based on a recent origin/master commit, you should call it master, and work there directly. it simplifies your life, and presents things as they actually are: you are directly developing on the master branch.

if develop is shared, it should not be rebased on master, just merged back into it with --no-ff. you are developing on develop. master and develop have different names, because we want them to be different things, and stay separate. do not make them same with rebase.

jQuery: using a variable as a selector

You're thinking too complicated. It's actually just $('#'+openaddress).

Difference between Activity Context and Application Context

Use getApplicationContext() if you need something tied to a Context that itself will have global scope.

If you use Activity, then the new Activity instance will have a reference, which has an implicit reference to the old Activity, and the old Activity cannot be garbage collected.

CSS flexbox vertically/horizontally center image WITHOUT explicitely defining parent height

Just add the following rules to the parent element:

display: flex;
justify-content: center; /* align horizontal */
align-items: center; /* align vertical */

Here's a sample demo (Resize window to see the image align)

Browser support for Flexbox nowadays is quite good.

For cross-browser compatibility for display: flex and align-items, you can add the older flexbox syntax as well:

display: -webkit-box;
display: -webkit-flex;
display: -moz-box;
display: -ms-flexbox;
display: flex;
-webkit-flex-align: center;
-ms-flex-align: center;
-webkit-align-items: center;
align-items: center;

Build query string for System.Net.HttpClient get

For those who do not want to include System.Web in projects that don't already use it, you can use FormUrlEncodedContent from System.Net.Http and do something like the following:

keyvaluepair version

string query;
using(var content = new FormUrlEncodedContent(new KeyValuePair<string, string>[]{
    new KeyValuePair<string, string>("ham", "Glazed?"),
    new KeyValuePair<string, string>("x-men", "Wolverine + Logan"),
    new KeyValuePair<string, string>("Time", DateTime.UtcNow.ToString()),
})) {
    query = content.ReadAsStringAsync().Result;
}

dictionary version

string query;
using(var content = new FormUrlEncodedContent(new Dictionary<string, string>()
{
    { "ham", "Glaced?"},
    { "x-men", "Wolverine + Logan"},
    { "Time", DateTime.UtcNow.ToString() },
})) {
    query = content.ReadAsStringAsync().Result;
}

Tips for using Vim as a Java IDE?

Use vim. ^-^ (gVim, to be precise)

You'll have it all (with some plugins).

Btw, snippetsEmu is a nice tool for coding with useful snippets (like in TextMate). You can use (or modify) a pre-made package or make your own.

Remove gutter space for a specific div only

Interesting...

Removing the gutter in Twitter Bootstrap's Default grid, that is, 940px wide. And that the default grid has a 940px wide container and has the bootstrap-responsive.css in it's stylesheet.

If I got your question right, this is how I did it...

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Stackoverflow Question</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="">
    <meta name="author" content="">

    <!-- Le styles -->
    <link rel="stylesheet" href="assets/css/bootstrap.css">
    <link rel="stylesheet" href="assets/css/bootstrap-responsive.css">

    <!-- HTML5 shim, for IE6-8 support of HTML5 elements -->
    <!--[if lt IE 9]>
      <script src="assets/js/html5shiv.js"></script>
    <![endif]-->




    <style type="text/css">
        #main_content [class*="span"] {
            margin-left: 0;
            width: 25%;
        }

        @media (min-width: 768px) and (max-width: 979px) {
            #main_content [class*="span"] {
            margin-left: 0;
            width: 25%;
            }
        }


        @media (max-width: 767px) {
            #main_content [class*="span"] {
            margin-left: 0;
            width: 100%;
            }
        }

        @media (max-width: 480px) {
            #main_content [class*="span"] {
            margin-left: 0;
            width: 100%;
            }
        }

        <!-- For Visual Aid Only -->
        .bg1 {
            background-color: #C2C2C2;
        }

        .bg2 {
            background-color: #D2D2D2;
        }
    </style>
  <body>
    <div id="wrap">
        <div class="container">
            <div class="row-fluid">
                <div class="span1 text-center bg1">01</div>
                <div class="span1 text-center bg2">02</div>
                <div class="span1 text-center bg1">03</div>
                <div class="span1 text-center bg2">04</div>
                <div class="span1 text-center bg1">05</div>
                <div class="span1 text-center bg2">06</div>
                <div class="span1 text-center bg1">07</div>
                <div class="span1 text-center bg2">08</div>
                <div class="span1 text-center bg1">09</div>
                <div class="span1 text-center bg2">10</div>
                <div class="span1 text-center bg1">11</div>
                <div class="span1 text-center bg2">12</div>
            </div>



            <div id="main_content">
                <div class="row-fluid">
                    <div class="span3 text-center bg1">1</div>
                    <div class="span3 text-center bg2">2</div>
                    <div class="span3 text-center bg1">3</div>
                    <div class="span3 text-center bg2">4</div>
                </div>
            </div>
        </div><!--/container-->
    </div>
  </body>
</html>

And the result is..

enter image description here

The 4 div span with no gutter will remain spanned for Small tablet landscape (800x600). Anything size smaller than that will collapse the 4 divs and it will be stacked vertically. Of course you will have to tweak it to fit your needs.

restart mysql server on windows 7

These suggestions so far only work if the mysql server is installed as a windows service.

If it is not installed as a service, you can start the server by using the Windows Start button ==> Run, then browse to the /bin folder under your mysql installation path and execute mysqld. Or just open a command window in the bin folder and type: mysqld

gcloud command not found - while installing Google Cloud SDK

You just have to execute this command as root

$ curl https://sdk.cloud.google.com | bash

Restart the terminal and that's it. Now all commands should be executed as root

jQuery bind to Paste Event, how to get the content of the paste

You could compare the original value of the field and the changed value of the field and deduct the difference as the pasted value. This catches the pasted text correctly even if there is existing text in the field.

http://jsfiddle.net/6b7sK/

function text_diff(first, second) {
    var start = 0;
    while (start < first.length && first[start] == second[start]) {
        ++start;
    }
    var end = 0;
    while (first.length - end > start && first[first.length - end - 1] == second[second.length - end - 1]) {
        ++end;
    }
    end = second.length - end;
    return second.substr(start, end - start);
}
$('textarea').bind('paste', function () {
    var self = $(this);
    var orig = self.val();
    setTimeout(function () {
        var pasted = text_diff(orig, $(self).val());
        console.log(pasted);
    });
});

PDF to image using Java

In Ghost4J library (http://ghost4j.sourceforge.net), since version 0.4.0 you can use a SimpleRenderer to do the job with few lines of code:

  1. Load PDF or PS file (use PSDocument class for that):

        PDFDocument document = new PDFDocument();
    document.load(new File("input.pdf"));

  2. Create the renderer

        SimpleRenderer renderer = new SimpleRenderer();

    // set resolution (in DPI)
    renderer.setResolution(300);

  3. Render

        List<Image> images = renderer.render(document);

Then you can do what you want with your image objects, for example, you can write them as PNG like this:

            for (int i = 0; i < images.size(); i++) {
                ImageIO.write((RenderedImage) images.get(i), "png", new File((i + 1) + ".png"));
            }

Note: Ghost4J uses the native Ghostscript C API so you need to have a Ghostscript installed on your box.

I hope it will help you :)

Convert NVARCHAR to DATETIME in SQL Server 2008

 
DECLARE @chr nvarchar(50) = (SELECT CONVERT(nvarchar(50), GETDATE(), 103))

SELECT @chr chars, CONVERT(date, @chr, 103) date_again

Converting a String to Object

A Java String is an Object. (String extends Object.)

So you can get an Object reference via assignment/initialisation:

String a = "abc";
Object b = a;

How to print binary number via printf

printf() doesn't directly support that. Instead you have to make your own function.

Something like:

while (n) {
    if (n & 1)
        printf("1");
    else
        printf("0");

    n >>= 1;
}
printf("\n");

How to declare Global Variables in Excel VBA to be visible across the Workbook

Your question is: are these not modules capable of declaring variables at global scope?

Answer: YES, they are "capable"

The only point is that references to global variables in ThisWorkbook or a Sheet module have to be fully qualified (i.e., referred to as ThisWorkbook.Global1, e.g.) References to global variables in a standard module have to be fully qualified only in case of ambiguity (e.g., if there is more than one standard module defining a variable with name Global1, and you mean to use it in a third module).

For instance, place in Sheet1 code

Public glob_sh1 As String

Sub test_sh1()
    Debug.Print (glob_mod)
    Debug.Print (ThisWorkbook.glob_this)
    Debug.Print (Sheet1.glob_sh1)
End Sub

place in ThisWorkbook code

Public glob_this As String

Sub test_this()
    Debug.Print (glob_mod)
    Debug.Print (ThisWorkbook.glob_this)
    Debug.Print (Sheet1.glob_sh1)
End Sub

and in a Standard Module code

Public glob_mod As String

Sub test_mod()
    glob_mod = "glob_mod"
    ThisWorkbook.glob_this = "glob_this"
    Sheet1.glob_sh1 = "glob_sh1"
    Debug.Print (glob_mod)
    Debug.Print (ThisWorkbook.glob_this)
    Debug.Print (Sheet1.glob_sh1)
End Sub

All three subs work fine.

PS1: This answer is based essentially on info from here. It is much worth reading (from the great Chip Pearson).

PS2: Your line Debug.Print ("Hello") will give you the compile error Invalid outside procedure.

PS3: You could (partly) check your code with Debug -> Compile VBAProject in the VB editor. All compile errors will pop.

PS4: Check also Put Excel-VBA code in module or sheet?.

PS5: You might be not able to declare a global variable in, say, Sheet1, and use it in code from other workbook (reading http://msdn.microsoft.com/en-us/library/office/gg264241%28v=office.15%29.aspx#sectionSection0; I did not test this point, so this issue is yet to be confirmed as such). But you do not mean to do that in your example, anyway.

PS6: There are several cases that lead to ambiguity in case of not fully qualifying global variables. You may tinker a little to find them. They are compile errors.

Split string into array of character strings

 
"cat".split("(?!^)")

This will produce

array ["c", "a", "t"]

How to refresh datagrid in WPF

Bind you Datagrid to an ObservableCollection, and update your collection instead.

Can't append <script> element

Adding the sourceURL in the script file helped as mentioned in this page: https://blog.getfirebug.com/2009/08/11/give-your-eval-a-name-with-sourceurl/

  1. In the script file, add a statement with sourceURL like "//@ sourceURL=foo.js"
  2. Load the script using jQuery $.getScript() and the script will be available in "sources" tab in chrome dev tools

Creating an IFRAME using JavaScript

It is better to process HTML as a template than to build nodes via JavaScript (HTML is not XML after all.) You can keep your IFRAME's HTML syntax clean by using a template and then appending the template's contents into another DIV.

<div id="placeholder"></div>

<script id="iframeTemplate" type="text/html">
    <iframe src="...">
        <!-- replace this line with alternate content -->
    </iframe>
</script>

<script type="text/javascript">
var element,
    html,
    template;

element = document.getElementById("placeholder");
template = document.getElementById("iframeTemplate");
html = template.innerHTML;

element.innerHTML = html;
</script>

JPA getSingleResult() or null

I solved this by using List<?> myList = query.getResultList(); and checking if myList.size() equals to zero.

How to use SVG markers in Google Maps API v3

You can render your icon using the SVG Path notation.

See Google documentation for more information.

Here is a basic example:

var icon = {

    path: "M-20,0a20,20 0 1,0 40,0a20,20 0 1,0 -40,0",
    fillColor: '#FF0000',
    fillOpacity: .6,
    anchor: new google.maps.Point(0,0),
    strokeWeight: 0,
    scale: 1
}

var marker = new google.maps.Marker({
    position: event.latLng,
    map: map,
    draggable: false,
    icon: icon
});

Here is a working example on how to display and scale a marker SVG icon:

JSFiddle demo

Edit:

Another example here with a complex icon:

JSFiddle demo

Edit 2:

And here is how you can have a SVG file as an icon:

JSFiddle demo

java.io.IOException: Server returned HTTP response code: 500

I had this problem i.e. works fine when pasted into browser but 505s when done through java. It was simply the spaces that needed to be escaped/encoded.

Mask output of `The following objects are masked from....:` after calling attach() function

It may be "better" to not use attach at all. On the plus side, you can save some typing if you use attach. Let's say your dataset is called mydata and you have variables called v1, v2, and v3. If you don't attach mydata, then you will type mean(mydata$v1) to get the mean of v1. If you do attach mydata, then you will type mean(v1) to get the mean of v1. But, if you don't detach the mydata dataset (every time), you'll get the message about the objects being masked going forward.

Solution 1 (assuming you want to attach):

  1. Use detach every time.
  2. See Dan Tarr's response if you already have the data attached (and it may be in the global environment several times). Then, in the future, use detach every time.

Solution 2

Don't use attach. Instead, include the dataset name every time you refer to a variable. The form is mydata$v1 (name of data set, dollar sign, name of variable).

As for me, I used solution 1 a lot in the past, but I've moved to solution 2. It's a bit more typing in the beginning, but if you are going to use the code multiple times, it just seems cleaner.

Pandas every nth row

 
df.drop(labels=df[df.index % 3 != 0].index, axis=0) #  every 3rd row (mod 3)

Finding current executable's path without /proc/self/exe

Making this work reliably across platforms requires using #ifdef statements.

The below code finds the executable's path in Windows, Linux, MacOS, Solaris or FreeBSD (although FreeBSD is untested). It uses Boost 1.55.0 (or later) to simplify the code, but it's easy enough to remove if you want. Just use defines like _MSC_VER and __linux as the OS and compiler require.

#include <string>
#include <boost/predef/os.h>

#if (BOOST_OS_WINDOWS)
#  include <stdlib.h>
#elif (BOOST_OS_SOLARIS)
#  include <stdlib.h>
#  include <limits.h>
#elif (BOOST_OS_LINUX)
#  include <unistd.h>
#  include <limits.h>
#elif (BOOST_OS_MACOS)
#  include <mach-o/dyld.h>
#elif (BOOST_OS_BSD_FREE)
#  include <sys/types.h>
#  include <sys/sysctl.h>
#endif

/*
 * Returns the full path to the currently running executable,
 * or an empty string in case of failure.
 */
std::string getExecutablePath() {
    #if (BOOST_OS_WINDOWS)
        char *exePath;
        if (_get_pgmptr(&exePath) != 0)
            exePath = "";
    #elif (BOOST_OS_SOLARIS)
        char exePath[PATH_MAX];
        if (realpath(getexecname(), exePath) == NULL)
            exePath[0] = '\0';
    #elif (BOOST_OS_LINUX)
        char exePath[PATH_MAX];
        ssize_t len = ::readlink("/proc/self/exe", exePath, sizeof(exePath));
        if (len == -1 || len == sizeof(exePath))
            len = 0;
        exePath[len] = '\0';
    #elif (BOOST_OS_MACOS)
        char exePath[PATH_MAX];
        uint32_t len = sizeof(exePath);
        if (_NSGetExecutablePath(exePath, &len) != 0) {
            exePath[0] = '\0'; // buffer too small (!)
        } else {
            // resolve symlinks, ., .. if possible
            char *canonicalPath = realpath(exePath, NULL);
            if (canonicalPath != NULL) {
                strncpy(exePath,canonicalPath,len);
                free(canonicalPath);
            }
        }
    #elif (BOOST_OS_BSD_FREE)
        char exePath[2048];
        int mib[4];  mib[0] = CTL_KERN;  mib[1] = KERN_PROC;  mib[2] = KERN_PROC_PATHNAME;  mib[3] = -1;
        size_t len = sizeof(exePath);
        if (sysctl(mib, 4, exePath, &len, NULL, 0) != 0)
            exePath[0] = '\0';
    #endif
        return std::string(exePath);
}

The above version returns full paths including the executable name. If instead you want the path without the executable name, #include boost/filesystem.hpp> and change the return statement to:

return strlen(exePath)>0 ? boost::filesystem::path(exePath).remove_filename().make_preferred().string() : std::string();

Xcode error "Could not find Developer Disk Image"

For iOS 10 beta 7, add the following link on the command line:

sudo ln -s /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/10.0\ \(14A5339a\) /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport

Read data from a text file using Java

Try using java.io.BufferedReader like this.

java.io.BufferedReader br = new java.io.BufferedReader(new java.io.InputStreamReader(new java.io.FileInputStream(fileName)));
String line = null;
while ((line = br.readLine()) != null){
//Process the line
}
br.close();

How does the stack work in assembly language?

I was searching about how stack works in terms of function and i found this blog its awesome and its explain concept of stack from scratch and how stack store value in stack.

Now on your answer . I will explain with python but you will get good idea how stack works in any language.

enter image description here

Its a program :

def hello(x):
    if x==1:
        return "op"
    else:
        u=1
        e=12
        s=hello(x-1)
        e+=1
        print(s)
        print(x)
        u+=1
    return e

hello(3)

enter image description here

enter image description here

Source : Cryptroix

some of its topic which it cover in blog:

How Function work ?
Calling a Function
 Functions In a Stack
 What is Return Address
 Stack
Stack Frame
Call Stack
Frame Pointer (FP) or Base Pointer (BP)
Stack Pointer (SP)
Allocation stack and deallocation of stack
StackoverFlow
What is Heap?

But its explain with python language so if you want you can take a look.

replace NULL with Blank value or Zero in sql server

You should always return the same type on all case condition:

In the first one you have an character and on the else you have an int.

You can use:

Select convert(varchar(11),isnull(totalamount,0))

or if you want with your solution: 

Case when total_amount = 0 then '0'   
else convert(varchar(11),isnull(total_amount, 0))  
end as total_amount

How do you query for "is not null" in Mongo?

An alternative that has not been mentioned, but that may be a more efficient option for some (won't work with NULL entries) is to use a sparse index (entries in the index only exist when there is something in the field). Here is a sample data set:

db.foo.find()
{ "_id" : ObjectId("544540b31b5cf91c4893eb94"), "imageUrl" : "http://example.com/foo.jpg" }
{ "_id" : ObjectId("544540ba1b5cf91c4893eb95"), "imageUrl" : "http://example.com/bar.jpg" }
{ "_id" : ObjectId("544540c51b5cf91c4893eb96"), "imageUrl" : "http://example.com/foo.png" }
{ "_id" : ObjectId("544540c91b5cf91c4893eb97"), "imageUrl" : "http://example.com/bar.png" }
{ "_id" : ObjectId("544540ed1b5cf91c4893eb98"), "otherField" : 1 }
{ "_id" : ObjectId("544540f11b5cf91c4893eb99"), "otherField" : 2 }

Now, create the sparse index on imageUrl field:

db.foo.ensureIndex( { "imageUrl": 1 }, { sparse: true } )
{
    "createdCollectionAutomatically" : false,
    "numIndexesBefore" : 1,
    "numIndexesAfter" : 2,
    "ok" : 1
}

Now, there is always a chance (and in particular with a small data set like my sample) that rather than using an index, MongoDB will use a table scan, even for a potential covered index query. As it turns out that gives me an easy way to illustrate the difference here:

db.foo.find({}, {_id : 0, imageUrl : 1})
{ "imageUrl" : "http://example.com/foo.jpg" }
{ "imageUrl" : "http://example.com/bar.jpg" }
{ "imageUrl" : "http://example.com/foo.png" }
{ "imageUrl" : "http://example.com/bar.png" }
{  }
{  }

OK, so the extra documents with no imageUrl are being returned, just empty, not what we wanted. Just to confirm why, do an explain:

db.foo.find({}, {_id : 0, imageUrl : 1}).explain()
{
    "cursor" : "BasicCursor",
    "isMultiKey" : false,
    "n" : 6,
    "nscannedObjects" : 6,
    "nscanned" : 6,
    "nscannedObjectsAllPlans" : 6,
    "nscannedAllPlans" : 6,
    "scanAndOrder" : false,
    "indexOnly" : false,
    "nYields" : 0,
    "nChunkSkips" : 0,
    "millis" : 0,
    "server" : "localhost:31100",
    "filterSet" : false
}

So, yes, a BasicCursor equals a table scan, it did not use the index. Let's force the query to use our sparse index with a hint():

db.foo.find({}, {_id : 0, imageUrl : 1}).hint({imageUrl : 1})
{ "imageUrl" : "http://example.com/bar.jpg" }
{ "imageUrl" : "http://example.com/bar.png" }
{ "imageUrl" : "http://example.com/foo.jpg" }
{ "imageUrl" : "http://example.com/foo.png" }

And there is the result we were looking for - only documents with the field populated are returned. This also only uses the index (i.e. it is a covered index query), so only the index needs to be in memory to return the results.

This is a specialized use case and can't be used generally (see other answers for those options). In particular it should be noted that as things stand you cannot use count() in this way (for my example it will return 6 not 4), so please only use when appropriate.

How to insert a text at the beginning of a file?

Just for fun, here is a solution using ed which does not have the problem of not working on an empty file. You can put it into a shell script just like any other answer to this question. 

ed Test <<EOF
a

.
0i
<added text>
.
1,+1 j
$ g/^$/d
wq
EOF

The above script adds the text to insert to the first line, and then joins the first and second line. To avoid ed exiting on error with an invalid join, it first creates a blank line at the end of the file and remove it later if it still exists.

Limitations: This script does not work if <added text> is exactly equal to a single period.

How to fix Array indexOf() in JavaScript for Internet Explorer browsers

it works for me.

if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function(elt /*, from*/) {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)? Math.ceil(from) : Math.floor(from);
    if (from < 0)
    from += len;

    for (; from < len; from++) {
      if (from in this && this[from] === elt)
        return from;
    }
    return -1;
  };
}

Laravel migration table field's type change

all other answers are Correct But Before you run

php artisan migrate

make sure you run this code first 

composer require doctrine/dbal

to avoid this error

RuntimeException : Changing columns for table "items" requires Doctrine DBAL; install "doctrine/dbal".

Is there a simple way to remove unused dependencies from a maven pom.xml?

The Maven Dependency Plugin will help, especially the dependency:analyze goal:

dependency:analyze analyzes the dependencies of this project and determines which are: used and declared; used and undeclared; unused and declared.

Another thing that might help to do some cleanup is the Dependency Convergence report from the Maven Project Info Reports Plugin.

How do I use IValidatableObject?

The problem with the accepted answer is that it now depends on the caller for the object to be properly validated. I would either remove the RangeAttribute and do the range validation inside the Validate method or I would create a custom attribute subclassing RangeAttribute that takes the name of the required property as an argument on the constructor.

For example:

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
class RangeIfTrueAttribute : RangeAttribute
{
    private readonly string _NameOfBoolProp;

    public RangeIfTrueAttribute(string nameOfBoolProp, int min, int max) : base(min, max)
    {
        _NameOfBoolProp = nameOfBoolProp;
    }

    public RangeIfTrueAttribute(string nameOfBoolProp, double min, double max) : base(min, max)
    {
        _NameOfBoolProp = nameOfBoolProp;
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var property = validationContext.ObjectType.GetProperty(_NameOfBoolProp);
        if (property == null)
            return new ValidationResult($"{_NameOfBoolProp} not found");

        var boolVal = property.GetValue(validationContext.ObjectInstance, null);

        if (boolVal == null || boolVal.GetType() != typeof(bool))
            return new ValidationResult($"{_NameOfBoolProp} not boolean");

        if ((bool)boolVal)
        {
            return base.IsValid(value, validationContext);
        }
        return null;
    }
}

How to filter an array/object by checking multiple values

You can use .filter() with boolean operators ie &&:

     var find = my_array.filter(function(result) {
       return result.param1 === "srting1" && result.param2 === 'string2';
     });
     
     return find[0];

How do I make bootstrap table rows clickable?

You can use in this way using bootstrap css. Just remove the active class if already assinged to any row and reassign to the current row.

    $(".table tr").each(function () {
        $(this).attr("class", "");
    });
    $(this).attr("class", "active");

How to check for a Null value in VB.NET

 
If Not editTransactionRow.pay_id AndAlso String.IsNullOrEmpty(editTransactionRow.pay_id.ToString()) = False Then
    stTransactionPaymentID = editTransactionRow.pay_id 'Check for null value
End If

Iterate over values of object

EcmaScript 2017 introduced Object.entries that allows you to iterate over values and keys. Documentation

var map = { key1 : 'value1', key2 : 'value2' }

for (let [key, value] of Object.entries(map)) {
    console.log(`${key}: ${value}`);
}

The result will be:

key1: value1
key2: value2

Opening PDF String in new window with javascript

An updated version of answer by @Noby Fujioka:

function showPdfInNewTab(base64Data, fileName) {  
  let pdfWindow = window.open("");
  pdfWindow.document.write("<html<head><title>"+fileName+"</title><style>body{margin: 0px;}iframe{border-width: 0px;}</style></head>");
  pdfWindow.document.write("<body><embed width='100%' height='100%' src='data:application/pdf;base64, " + encodeURI(base64Data)+"#toolbar=0&navpanes=0&scrollbar=0'></embed></body></html>");
}

Why is Java Vector (and Stack) class considered obsolete or deprecated?

Besides the already stated answers about using Vector, Vector also has a bunch of methods around enumeration and element retrieval which are different than the List interface, and developers (especially those who learned Java before 1.2) can tend to use them if they are in the code. Although Enumerations are faster, they don't check if the collection was modified during iteration, which can cause issues, and given that Vector might be chosen for its syncronization - with the attendant access from multiple threads, this makes it a particularly pernicious problem. Usage of these methods also couples a lot of code to Vector, such that it won't be easy to replace it with a different List implementation.

Convert this string to datetime

The Problem is with your code formatting,

inorder to use strtotime() You should replace '06/Oct/2011:19:00:02' with 06/10/2011 19:00:02 and date('d/M/Y:H:i:s', $date); with date('d/M/Y H:i:s', $date);. Note the spaces in between.

So the final code looks like this

$s = '06/10/2011 19:00:02';
$date = strtotime($s);
echo date('d/M/Y H:i:s', $date);

How can I add a space in between two outputs?

code:

class Main
{
    public static void main(String[] args)  
    {
        int a=10, b=20;
        System.out.println(a + " " + b);
    }
}

Input: none

Output: 10 20

URL to compose a message in Gmail (with full Gmail interface and specified to, bcc, subject, etc.)

Many others have done an excellent job here giving a basic answer, especially Tobias Mühl. As mentioned, GMail's Api very closely matches the definition given by RFC2368 and RFC6068. This is true of the extended form of the mailto: links, but it's also true in the commonly-used forms found in the other answers. Of the five parameters, four are identical (such as to, cc, bcc and body) and one received only slight modification (su is gmail's version of subject).

If you want to know more about what you can do with mailTo gmail URLs, then these RFCs might be of help. Unfortunately, Google has not published any source themselves.

To clarify the parameters:

  • to - Email to who
  • su (gmail API) / subject (mailTo API) - Email Title
  • body - Email Body
  • bcc - Email Blind-Carbon Copy
  • cc - Email Carbon Copy address

How to cast a double to an int in Java by rounding it down?

To cast a double to an int and have it be rounded to the nearest integer (i.e. unlike the typical (int)(1.8) and (int)(1.2), which will both "round down" towards 0 and return 1), simply add 0.5 to the double that you will typecast to an int.

For example, if we have

double a = 1.2;
double b = 1.8;

Then the following typecasting expressions for x and y and will return the rounded-down values (x = 1 and y = 1):

int x = (int)(a);   // This equals (int)(1.2) --> 1
int y = (int)(b);   // This equals (int)(1.8) --> 1

But by adding 0.5 to each, we will obtain the rounded-to-closest-integer result that we may desire in some cases (x = 1 and y = 2):

int x = (int)(a + 0.5);   // This equals (int)(1.8) --> 1
int y = (int)(b + 0.5);   // This equals (int)(2.3) --> 2

As a small note, this method also allows you to control the threshold at which the double is rounded up or down upon (int) typecasting. 

(int)(a + 0.8);

to typecast. This will only round up to (int)a + 1 whenever the decimal values are greater than or equal to 0.2. That is, by adding 0.8 to the double immediately before typecasting, 10.15 and 10.03 will be rounded down to 10 upon (int) typecasting, but 10.23 and 10.7 will be rounded up to 11.

Failed to add a service. Service metadata may not be accessible. Make sure your service is running and exposing metadata.`

After Add this to your web.config file and configure according to your service name and contract name.

<behaviors>
   <serviceBehaviors>
      <behavior name="metadataBehavior">
         <serviceMetadata httpGetEnabled="true" />
      </behavior>
   </serviceBehaviors>
</behaviors>
<services>
   <service name="MyService.MyService" behaviorConfiguration="metadataBehavior">
      <endpoint 
          address=""   <!-- don't put anything here - Cassini will determine address -->
          binding="basicHttpBinding" 
          contract="MyService.IMyService"/>
      <endpoint 
          address="mex" 
          binding="mexHttpBinding" 
          contract="IMetadataExchange"/>
   </service>
</services>

Please add this in your Service.svc

using System.ServiceModel.Description;

Hope it will helps you.

Assert that a WebElement is not present using Selenium WebDriver with java

Not an answer to the very question but perhaps an idea for the underlying task:

When your site logic should not show a certain element, you could insert an invisible "flag" element that you check for.

if condition
    renderElement()
else
    renderElementNotShownFlag() // used by Selenium test

Auto-redirect to another HTML page

If you want to redirect your webpage to another HTML FILE, just use as followed:

<meta http-equiv="refresh" content"2;otherpage.html">

2 being the seconds you want the client to wait before redirecting. Use "url=" only when it's an URL, to redirect to an HTML file just write the name after the ';'

How to get JSON Key and Value?

 
$.each(result, function(key, value) {
  console.log(key+ ':' + value);
});

Closing pyplot windows

plt.close() will close current instance.

plt.close(2) will close figure 2

plt.close(plot1) will close figure with instance plot1

plt.close('all') will close all fiures

Found here.

Remember that plt.show() is a blocking function, so in the example code you used above, plt.close() isn't being executed until the window is closed, which makes it redundant.

You can use plt.ion() at the beginning of your code to make it non-blocking, although this has other implications.

EXAMPLE

After our discussion in the comments, I've put together a bit of an example just to demonstrate how the plot functionality can be used.

Below I create a plot:

fig = plt.figure(figsize=plt.figaspect(0.75))
ax = fig.add_subplot(1, 1, 1)
....
par_plot, = plot(x_data,y_data, lw=2, color='red')

In this case, ax above is a handle to a pair of axes. Whenever I want to do something to these axes, I can change my current set of axes to this particular set by calling axes(ax).

par_plot is a handle to the line2D instance. This is called an artist. If I want to change a property of the line, like change the ydata, I can do so by referring to this handle.

I can also create a slider widget by doing the following:

axsliderA = axes([0.12, 0.85, 0.16, 0.075])
sA = Slider(axsliderA, 'A', -1, 1.0, valinit=0.5)
sA.on_changed(update)

The first line creates a new axes for the slider (called axsliderA), the second line creates a slider instance sA which is placed in the axes, and the third line specifies a function to call when the slider value changes (update).

My update function could look something like this:

def update(val):
    A = sA.val
    B = sB.val
    C = sC.val
    y_data = A*x_data*x_data + B*x_data + C
    par_plot.set_ydata(y_data)
    draw()

The par_plot.set_ydata(y_data) changes the ydata property of the Line2D object with the handle par_plot.

The draw() function updates the current set of axes.

Putting it all together:

from pylab import *
import matplotlib.pyplot as plt
import numpy

def update(val):
    A = sA.val
    B = sB.val
    C = sC.val
    y_data = A*x_data*x_data + B*x_data + C
    par_plot.set_ydata(y_data)
    draw()


x_data = numpy.arange(-100,100,0.1);

fig = plt.figure(figsize=plt.figaspect(0.75))
ax = fig.add_subplot(1, 1, 1)
subplots_adjust(top=0.8)

ax.set_xlim(-100, 100);
ax.set_ylim(-100, 100);
ax.set_xlabel('X')
ax.set_ylabel('Y')

axsliderA = axes([0.12, 0.85, 0.16, 0.075])
sA = Slider(axsliderA, 'A', -1, 1.0, valinit=0.5)
sA.on_changed(update)

axsliderB = axes([0.43, 0.85, 0.16, 0.075])
sB = Slider(axsliderB, 'B', -30, 30.0, valinit=2)
sB.on_changed(update)

axsliderC = axes([0.74, 0.85, 0.16, 0.075])
sC = Slider(axsliderC, 'C', -30, 30.0, valinit=1)
sC.on_changed(update)

axes(ax)
A = 1;
B = 2;
C = 1;
y_data = A*x_data*x_data + B*x_data + C;

par_plot, = plot(x_data,y_data, lw=2, color='red')

show()

A note about the above: When I run the application, the code runs sequentially right through (it stores the update function in memory, I think), until it hits show(), which is blocking. When you make a change to one of the sliders, it runs the update function from memory (I think?).

This is the reason why show() is implemented in the way it is, so that you can change values in the background by using functions to process the data.

How do I format a date as ISO 8601 in moment.js?

 
var x = moment();

//date.format(moment.ISO_8601); // error

moment("2010-01-01T05:06:07", ["YYYY", moment.ISO_8601]);; // error
document.write(x);

How to create an infinite loop in Windows batch file?

How about using good(?) old goto?

:loop

echo Ooops

goto loop

See also this for a more useful example.

Adding hours to JavaScript Date object?

JavaScript itself has terrible Date/Time API's. Nonetheless, you can do this in pure JavaScript:

Date.prototype.addHours = function(h) {
  this.setTime(this.getTime() + (h*60*60*1000));
  return this;
}

Rename computer and join to domain in one step with PowerShell

If you create the machine account on the DC first, then you can change the name and join the domain in one reboot.

How to make a 3D scatter plot in Python?

You can use matplotlib for this. matplotlib has a mplot3d module that will do exactly what you want.

from matplotlib import pyplot
from mpl_toolkits.mplot3d import Axes3D
import random


fig = pyplot.figure()
ax = Axes3D(fig)

sequence_containing_x_vals = list(range(0, 100))
sequence_containing_y_vals = list(range(0, 100))
sequence_containing_z_vals = list(range(0, 100))

random.shuffle(sequence_containing_x_vals)
random.shuffle(sequence_containing_y_vals)
random.shuffle(sequence_containing_z_vals)

ax.scatter(sequence_containing_x_vals, sequence_containing_y_vals, sequence_containing_z_vals)
pyplot.show()

The code above generates a figure like:

matplotlib 3D image

What is the difference between Swing and AWT?

Java 8

Swing

  • It is a part of Java Foundation Classes
  • Swing is built on AWT
  • Swing components are lightweight
  • Swing supports pluggable look and feel
  • Platform independent
  • Uses MVC : Model-View-Controller architecture
  • package : javax.swing
  • Unlike Swing’s other components, which are lightweight, the top-level containers are heavyweight.

AWT - Abstract Window Toolkit

  • Platform dependent
  • AWT components are heavyweight
  • package java.awt

Convert double to string C++?

In C++11, use std::to_string if you can accept the default format (%f).

storedCorrect[count]= "(" + std::to_string(c1) + ", " + std::to_string(c2) + ")";

How to redirect the output of a PowerShell to a file during its execution

If you want to do it from the command line and not built into the script itself, use:

.\myscript.ps1 | Out-File c:\output.csv

Symfony - generate url with parameter in controller

Get the router from the container.

$router = $this->get('router');

Then use the router to generate the Url

$uri = $router->generate('blog_show', array('slug' => 'my-blog-post'));

C# - How to convert string to char?

 
string[] array = {"USA", "ITLY"};
char[] element1 = array[0].ToCharArray();
// Now for element no 2
char[] element2 = array[1].ToCharArray();

Compression/Decompression string with C#

The code to compress/decompress a string

public static void CopyTo(Stream src, Stream dest) {
    byte[] bytes = new byte[4096];

    int cnt;

    while ((cnt = src.Read(bytes, 0, bytes.Length)) != 0) {
        dest.Write(bytes, 0, cnt);
    }
}

public static byte[] Zip(string str) {
    var bytes = Encoding.UTF8.GetBytes(str);

    using (var msi = new MemoryStream(bytes))
    using (var mso = new MemoryStream()) {
        using (var gs = new GZipStream(mso, CompressionMode.Compress)) {
            //msi.CopyTo(gs);
            CopyTo(msi, gs);
        }

        return mso.ToArray();
    }
}

public static string Unzip(byte[] bytes) {
    using (var msi = new MemoryStream(bytes))
    using (var mso = new MemoryStream()) {
        using (var gs = new GZipStream(msi, CompressionMode.Decompress)) {
            //gs.CopyTo(mso);
            CopyTo(gs, mso);
        }

        return Encoding.UTF8.GetString(mso.ToArray());
    }
}

static void Main(string[] args) {
    byte[] r1 = Zip("StringStringStringStringStringStringStringStringStringStringStringStringStringString");
    string r2 = Unzip(r1);
}

Remember that Zip returns a byte[], while Unzip returns a string. If you want a string from Zip you can Base64 encode it (for example by using Convert.ToBase64String(r1)) (the result of Zip is VERY binary! It isn't something you can print to the screen or write directly in an XML)

The version suggested is for .NET 2.0, for .NET 4.0 use the MemoryStream.CopyTo.

IMPORTANT: The compressed contents cannot be written to the output stream until the GZipStream knows that it has all of the input (i.e., to effectively compress it needs all of the data). You need to make sure that you Dispose() of the GZipStream before inspecting the output stream (e.g., mso.ToArray()). This is done with the using() { } block above. Note that the GZipStream is the innermost block and the contents are accessed outside of it. The same goes for decompressing: Dispose() of the GZipStream before attempting to access the data.

Check free disk space for current partition in bash

To know the usage of the specific directory in GB's or TB's in linux the command is,

df -h /dir/inner_dir/ 

 or

df -sh /dir/inner_dir/

and to know the usage of the specific directory in bits in linux the command is,

df-k /dir/inner_dir/

How to handle ETIMEDOUT error?

This is caused when your request response is not received in given time(by timeout request module option).

Basically to catch that error first, you need to register a handler on error, so the unhandled error won't be thrown anymore: out.on('error', function (err) { /* handle errors here */ }). Some more explanation here.

In the handler you can check if the error is ETIMEDOUT and apply your own logic: if (err.message.code === 'ETIMEDOUT') { /* apply logic */ }.

If you want to request for the file again, I suggest using node-retry or node-backoff modules. It makes things much simpler.

If you want to wait longer, you can set timeout option of request yourself. You can set it to 0 for no timeout.

Regex - how to match everything except a particular pattern

notnot, resurrecting this ancient question because it had a simple solution that wasn't mentioned. (Found your question while doing some research for a regex bounty quest.)

I'm faced with a situation where I have to match an (A and ~B) pattern.

The basic regex for this is frighteningly simple: B|(A)

You just ignore the overall matches and examine the Group 1 captures, which will contain A.

An example (with all the disclaimers about parsing html in regex): A is digits, B is digits within <a tag

The regex: <a.*?<\/a>|(\d+)

Demo (look at Group 1 in the lower right pane)

Reference

How to match pattern except in situations s1, s2, s3

How to match a pattern unless...

Best practice to look up Java Enum

Guava also provides such function which will return an Optional if an enum cannot be found. 

Enums.getIfPresent(MyEnum.class, id).toJavaUtil()
            .orElseThrow(()-> new RuntimeException("Invalid enum blah blah blah.....")))

How to specify multiple return types using type-hints

Python 3.10 (use |): Example for a function which takes a single argument that is either an int or str and returns either an int or str:

def func(arg: int | str) -> int | str:
              ^^^^^^^^^     ^^^^^^^^^ 
             type of arg   return type

Python 3.5 - 3.9 (use typing.Union):

from typing import Union
def func(arg: Union[int, str]) -> Union[int, str]:
              ^^^^^^^^^^^^^^^     ^^^^^^^^^^^^^^^ 
                type of arg         return type

For the special case of X | None you can use Optional[X].

Cannot get OpenCV to compile because of undefined references?

For me, this type of error:

mingw-w64-x86_64/lib/gcc/x86_64-w64-mingw32/8.2.0/../../../../x86_64-w64-mingw32/bin/ld: mingw-w64-x86_64/x86_64-w64-mingw32/lib/libTransform360.a(VideoFrameTransform.cpp.obj):VideoFrameTransform.cpp:(.text+0xc7c):
undefined reference to `cv::Mat::Mat(cv::Mat const&, cv::Rect_<int> const&)'

meant load order, I had to do -lTransform360 -lopencv_dnn345 -lopencv... just like that, that order. And putting them right next to each other helped too, don't put -lTransform360 all the way at the beginning...or you'll get, for some freaky reason:

undefined reference to `VideoFrameTransform_new'
undefined reference to `VideoFrameTransform_generateMapForPlane'

...

jQuery .each() index?

surprise to see that no have given this syntax.

.each syntax with data or collection

jQuery.each(collection, callback(indexInArray, valueOfElement));

OR 

jQuery.each( jQuery('#list option'), function(indexInArray, valueOfElement){
//your code here
});

is it possible to evenly distribute buttons across the width of an android linearlayout

You should use an android:weightSum attribute linear layout. Give linear layout a weightSum equal to the number of Buttons inside the layout, then set android:layout_weight="1" and set width of the button android:layout_width="0dp" further, you can style the layout using paddings and layout margins.

<LinearLayout android:id="@+id/LinearLayout01"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:gravity="center"
    android:weightSum="3">
    
    <Button
        android:id="@+id/btnOne"
        android:layout_width="0dp"
        android:text="1"
        android:layout_height="wrap_content"
        android:width="120dip"
        android:layout_weight="1"
        android:layout_margin="15dp" 
        />
    
    <Button
        android:id="@+id/btnTwo"
        android:text="2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:width="120dip"
        android:layout_weight="1"
        android:layout_margin="15dp" />

    <Button
        android:id="@+id/btnThree"
        android:text="3"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:width="120dip"
        android:layout_weight="1"
        android:layout_margin="15dp" />

</LinearLayout>

In order to do it dynamically

void initiate(Context context){
    LinearLayout parent = new LinearLayout(context);

    parent.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
    parent.setWeightSum(3);
    parent.setOrientation(LinearLayout.HORIZONTAL);

    AppCompatButton button1 = new AppCompatButton(context);
    button1.setLayoutParams(new LinearLayout.LayoutParams(0 ,LinearLayout.LayoutParams.WRAP_CONTENT,1.0f));

    AppCompatButton button2 = new AppCompatButton(context);
    button2.setLayoutParams(new LinearLayout.LayoutParams(0 ,LinearLayout.LayoutParams.WRAP_CONTENT,1.0f));

    AppCompatButton button3 = new AppCompatButton(context);
    button3.setLayoutParams(new LinearLayout.LayoutParams(0 ,LinearLayout.LayoutParams.WRAP_CONTENT,1.0f));
    
    parent.addView(button1);
    parent.addView(button2);
    parent.addView(button3);

}

concat yesterdays date with a specific time

 
where date_dt = to_date(to_char(sysdate-1, 'YYYY-MM-DD') || ' 19:16:08', 'YYYY-MM-DD HH24:MI:SS')

should work.

How to schedule a periodic task in Java?

If you want to stick with java.util.Timer, you can use it to schedule at large time intervals. You simply pass in the period you are shooting for. Check the documentation here.

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

My issue was a little different. Instead of jdbc:oracle:thin:@server:port/service i had it as server:port/service.

Missing was jdbc:oracle:thin:@ in url attribute in GlobalNamingResources.Resource. But I overlooked tomcat exception's 

java.sql.SQLException: Cannot create JDBC driver of class 'oracle.jdbc.driver.OracleDriver' for connect URL 'server:port/service'

Avoiding NullPointerException in Java

Null is not a 'problem'. It is an integral part of a complete modeling tool set. Software aims to model the complexity of the world and null bears its burden. Null indicates 'No data' or 'Unknown' in Java and the like. So it is appropriate to use nulls for these purposes. I don't prefer the 'Null object' pattern; I think it rise the 'who will guard the guardians' problem.
If you ask me what is the name of my girlfriend I'll tell you that I have no girlfriend. In the Java language I'll return null. An alternative would be to throw meaningful exception to indicate some problem that can't be (or don't want to be) solved right there and delegate it somewhere higher in the stack to retry or report data access error to the user.

  1. For an 'unknown question' give 'unknown answer'. (Be null-safe where this is correct from business point of view) Checking arguments for null once inside a method before usage relieves multiple callers from checking them before a call.

    public Photo getPhotoOfThePerson(Person person) {
    if (person == null)
        return null;
    // Grabbing some resources or intensive calculation
    // using person object anyhow.
}

    Previous leads to normal logic flow to get no photo of a non-existent girlfriend from my photo library.

    getPhotoOfThePerson(me.getGirlfriend())

    And it fits with new coming Java API (looking forward)

    getPhotoByName(me.getGirlfriend()?.getName())

    While it is rather 'normal business flow' not to find photo stored into the DB for some person, I used to use pairs like below for some other cases

    public static MyEnum parseMyEnum(String value); // throws IllegalArgumentException
public static MyEnum parseMyEnumOrNull(String value);

    And don't loathe to type <alt> + <shift> + <j> (generate javadoc in Eclipse) and write three additional words for you public API. This will be more than enough for all but those who don't read documentation.

    /**
 * @return photo or null
 */

    or

    /**
 * @return photo, never null
 */

  2. This is rather theoretical case and in most cases you should prefer java null safe API (in case it will be released in another 10 years), but NullPointerException is subclass of an Exception. Thus it is a form of Throwable that indicates conditions that a reasonable application might want to catch (javadoc)! To use the first most advantage of exceptions and separate error-handling code from 'regular' code (according to creators of Java) it is appropriate, as for me, to catch NullPointerException.

    public Photo getGirlfriendPhoto() {
    try {
        return appContext.getPhotoDataSource().getPhotoByName(me.getGirlfriend().getName());
    } catch (NullPointerException e) {
        return null;
    }
}

    Questions could arise:

    Q. What if getPhotoDataSource() returns null?
    A. It is up to business logic. If I fail to find a photo album I'll show you no photos. What if appContext is not initialized? This method's business logic puts up with this. If the same logic should be more strict then throwing an exception it is part of the business logic and explicit check for null should be used (case 3). The new Java Null-safe API fits better here to specify selectively what implies and what does not imply to be initialized to be fail-fast in case of programmer errors.

    Q. Redundant code could be executed and unnecessary resources could be grabbed.
    A. It could take place if getPhotoByName() would try to open a database connection, create PreparedStatement and use the person name as an SQL parameter at last. The approach for an unknown question gives an unknown answer (case 1) works here. Before grabbing resources the method should check parameters and return 'unknown' result if needed.

    Q. This approach has a performance penalty due to the try closure opening.
    A. Software should be easy to understand and modify firstly. Only after this, one could think about performance, and only if needed! and where needed! (source), and many others).

    PS. This approach will be as reasonable to use as the separate error-handling code from "regular" code principle is reasonable to use in some place. Consider the next example:

    public SomeValue calculateSomeValueUsingSophisticatedLogic(Predicate predicate) {
    try {
        Result1 result1 = performSomeCalculation(predicate);
        Result2 result2 = performSomeOtherCalculation(result1.getSomeProperty());
        Result3 result3 = performThirdCalculation(result2.getSomeProperty());
        Result4 result4 = performLastCalculation(result3.getSomeProperty());
        return result4.getSomeProperty();
    } catch (NullPointerException e) {
        return null;
    }
}

public SomeValue calculateSomeValueUsingSophisticatedLogic(Predicate predicate) {
    SomeValue result = null;
    if (predicate != null) {
        Result1 result1 = performSomeCalculation(predicate);
        if (result1 != null && result1.getSomeProperty() != null) {
            Result2 result2 = performSomeOtherCalculation(result1.getSomeProperty());
            if (result2 != null && result2.getSomeProperty() != null) {
                Result3 result3 = performThirdCalculation(result2.getSomeProperty());
                if (result3 != null && result3.getSomeProperty() != null) {
                    Result4 result4 = performLastCalculation(result3.getSomeProperty());
                    if (result4 != null) {
                        result = result4.getSomeProperty();
                    }
                }
            }
        }
    }
    return result;
}

    PPS. For those fast to downvote (and not so fast to read documentation) I would like to say that I've never caught a null-pointer exception (NPE) in my life. But this possibility was intentionally designed by the Java creators because NPE is a subclass of Exception. We have a precedent in Java history when ThreadDeath is an Error not because it is actually an application error, but solely because it was not intended to be caught! How much NPE fits to be an Error than ThreadDeath! But it is not.

  3. Check for 'No data' only if business logic implies it.

    public void updatePersonPhoneNumber(Long personId, String phoneNumber) {
    if (personId == null)
        return;
    DataSource dataSource = appContext.getStuffDataSource();
    Person person = dataSource.getPersonById(personId);
    if (person != null) {
        person.setPhoneNumber(phoneNumber);
        dataSource.updatePerson(person);
    } else {
        Person = new Person(personId);
        person.setPhoneNumber(phoneNumber);
        dataSource.insertPerson(person);
    }
}

    and

    public void updatePersonPhoneNumber(Long personId, String phoneNumber) {
    if (personId == null)
        return;
    DataSource dataSource = appContext.getStuffDataSource();
    Person person = dataSource.getPersonById(personId);
    if (person == null)
        throw new SomeReasonableUserException("What are you thinking about ???");
    person.setPhoneNumber(phoneNumber);
    dataSource.updatePerson(person);
}

    If appContext or dataSource is not initialized unhandled runtime NullPointerException will kill current thread and will be processed by Thread.defaultUncaughtExceptionHandler (for you to define and use your favorite logger or other notification mechanizm). If not set, ThreadGroup#uncaughtException will print stacktrace to system err. One should monitor application error log and open Jira issue for each unhandled exception which in fact is application error. Programmer should fix bug somewhere in initialization stuff.

Reducing the gap between a bullet and text in a list item

I've tried these and other solutions offered, which don't actually work, but I seem to have found a way to do this, and that is to remove the bullet and use the :before pseudo-element to put a Unicode bullet in its place. Then you can adjust the the space between the list item and bullet. You have to use Unicode to insert an entity into the content property of :before or :after - HTML entities don't work.

There's some sizing and positioning code needed too, because the Unicode bullet by default displays the size of a pinhead. So the bullet has to be enlarged and absolutely positioned to get it into place. Note the use of ems for the bullet's sizing and positioning so that the bullet's relationship to the list item stays constant when your change the font size of the list item. The comments in the code explain how it all works. If you want to use a different entity, you can find a list of the Unicode entities here:

http://www.evotech.net/blog/2007/04/named-html-entities-in-numeric-order/

Use a value from the far right column (octal) from the table on this page - you just need the \ and number. You should be able to trash everying except the content property from the :before rule when using the other entities as they seem to display at a useable size. Email me: charles at stylinwithcss dot com with any thoughts/comments. I tested it Firefox, Chrome and Safari and it works nicely.

    body {
      font-family:"Trebuchet MS", sans-serif;
      }
    li  {
      font-size:14px;        /* set font size of list item and bullet here */
      list-style-type:none; /* removes default bullet */
      position:relative;      /* positioning context for bullet */
      }
      li:before  {
        content:"\2219";    /* escaped unicode character */
        font-size:2.5em;    /* the default unicode bullet size is very small */
        line-height:0;        /* kills huge line height on resized bullet */
        position:absolute;  /* position bullet relative to list item */
        top:.23em;           /* vertical align bullet position relative to list item */
        left:-.5em;            /* position the bullet L- R relative to list item */
       }

Render basic HTML view?

It is very sad that it is about 2020 still express hasn't added a way to render an HTML page without using sendFile method of the response object. Using sendFile is not a problem but passing argument to it in the form of path.join(__dirname, 'relative/path/to/file') doesn't feel right. Why should a user join __dirname to the file path? It should be done by default. Why can't the root of the server be by defalut the project directory? Also, installing a templating dependency just to render a static HTML file is again not correct. I don't know the correct way to tackle the issue, but if I had to serve a static HTML, then I would do something like:

const PORT = 8154;

const express = require('express');
const app = express();

app.use(express.static('views'));

app.listen(PORT, () => {
    console.log(`Server is listening at port http://localhost:${PORT}`);
});

The above example assumes that the project structure has a views directory and the static HTML files are inside it. For example, let's say, the views directory has two HTML files named index.html and about.html, then to access them, we can visit: localhost:8153/index.html or just localhost:8153/ to load the index.html page and localhost:8153/about.html to load the about.html. We can use a similar approach to serve a react/angular app by storing the artifacts in the views directory or just using the default dist/<project-name> directory and configure it in the server js as follows:

app.use(express.static('dist/<project-name>'));

Multiple Java versions running concurrently under Windows

It is absolutely possible to install side-by-side several JRE/JDK versions. Moreover, you don't have to do anything special for that to happen, as Sun is creating a different folder for each (under Program Files).

There is no control panel to check which JRE works for each application. Basically, the JRE that will work would be the first in your PATH environment variable. You can change that, or the JAVA_HOME variable, or create specific cmd/bat files to launch the applications you desire, each with a different JRE in path.

Stored Procedure error ORA-06550

Could you try this one:

create or replace 
procedure point_triangle
IS
BEGIN
  FOR thisteam in (select P.FIRSTNAME,P.LASTNAME, SUM(P.PTS) S from PLAYERREGULARSEASON P  where P.TEAM = 'IND'  group by P.FIRSTNAME, P.LASTNAME order by SUM(P.PTS) DESC)
  LOOP
    dbms_output.put_line(thisteam.FIRSTNAME|| ' ' || thisteam.LASTNAME  || ':' || thisteam.S);
  END LOOP;

END;

Delete a closed pull request from GitHub

There is no way you can delete a pull request yourself -- you and the repo owner (and all users with push access to it) can close it, but it will remain in the log. This is part of the philosophy of not denying/hiding what happened during development.

However, if there are critical reasons for deleting it (this is mainly violation of Github Terms of Service), Github support staff will delete it for you.

Whether or not they are willing to delete your PR for you is something you can easily ask them, just drop them an email at [email protected]

UPDATE: Currently Github requires support requests to be created here: https://support.github.com/contact

update query with join on two tables

Officially, the SQL languages does not support a JOIN or FROM clause in an UPDATE statement unless it is in a subquery. Thus, the Hoyle ANSI approach would be something like

Update addresses
Set cid = (
            Select c.id
            From customers As c
            where c.id = a.id
            )
Where Exists    (
                Select 1
                From customers As C1
                Where C1.id = addresses.id
                )

However many DBMSs such Postgres support the use of a FROM clause in an UPDATE statement. In many cases, you are required to include the updating table and alias it in the FROM clause however I'm not sure about Postgres:

Update addresses
Set cid = c.id
From addresses As a
    Join customers As c
        On c.id = a.id

Binary Data Posting with curl

You don't need --header "Content-Length: $LENGTH".

curl --request POST --data-binary "@template_entry.xml" $URL

Note that GET request does not support content body widely.

Also remember that POST request have 2 different coding schema. This is first form:

  $ nc -l -p 6666 &
  $ curl  --request POST --data-binary "@README" http://localhost:6666

POST / HTTP/1.1
User-Agent: curl/7.21.0 (x86_64-pc-linux-gnu) libcurl/7.21.0 OpenSSL/0.9.8o zlib/1.2.3.4 libidn/1.15 libssh2/1.2.6
Host: localhost:6666
Accept: */*
Content-Length: 9309
Content-Type: application/x-www-form-urlencoded
Expect: 100-continue

.. -*- mode: rst; coding: cp1251; fill-column: 80 -*-
.. rst2html.py README README.html
.. contents::

You probably request this:

-F/--form name=content
           (HTTP) This lets curl emulate a filled-in form in
              which a user has pressed the submit button. This
              causes curl to POST data using the Content- Type
              multipart/form-data according to RFC2388. This
              enables uploading of binary files etc. To force the
              'content' part to be a file, prefix the file name
              with an @ sign. To just get the content part from a
              file, prefix the file name with the symbol <. The
              difference between @ and < is then that @ makes a
              file get attached in the post as a file upload,
              while the < makes a text field and just get the
              contents for that text field from a file.

What is DOM Event delegation?

DOM event delegation is a mechanism of responding to ui-events via a single common parent rather than each child, through the magic of event "bubbling" (aka event propagation).

When an event is triggered on an element, the following occurs:

The event is dispatched to its target EventTarget and any event listeners found there are triggered. Bubbling events will then trigger any additional event listeners found by following the EventTarget's parent chain upward, checking for any event listeners registered on each successive EventTarget. This upward propagation will continue up to and including the Document.

Event bubbling provides the foundation for event delegation in browsers. Now you can bind an event handler to a single parent element, and that handler will get executed whenever the event occurs on any of its child nodes (and any of their children in turn). This is event delegation. Here's an example of it in practice:

<ul onclick="alert(event.type + '!')">
    <li>One</li>
    <li>Two</li>
    <li>Three</li>
</ul>

With that example if you were to click on any of the child <li> nodes, you would see an alert of "click!", even though there is no click handler bound to the <li> you clicked on. If we bound onclick="..." to each <li> you would get the same effect.

So what's the benefit?

Imagine you now have a need to dynamically add new <li> items to the above list via DOM manipulation:

var newLi = document.createElement('li');
newLi.innerHTML = 'Four';
myUL.appendChild(newLi);

Without using event delegation you would have to "rebind" the "onclick" event handler to the new <li> element, in order for it to act the same way as its siblings. With event delegation you don't need to do anything. Just add the new <li> to the list and you're done.

This is absolutely fantastic for web apps with event handlers bound to many elements, where new elements are dynamically created and/or removed in the DOM. With event delegation the number of event bindings can be drastically decreased by moving them to a common parent element, and code that dynamically creates new elements on the fly can be decoupled from the logic of binding their event handlers.

Another benefit to event delegation is that the total memory footprint used by event listeners goes down (since the number of event bindings go down). It may not make much of a difference to small pages that unload often (i.e. user's navigate to different pages often). But for long-lived applications it can be significant. There are some really difficult-to-track-down situations when elements removed from the DOM still claim memory (i.e. they leak), and often this leaked memory is tied to an event binding. With event delegation you're free to destroy child elements without risk of forgetting to "unbind" their event listeners (since the listener is on the ancestor). These types of memory leaks can then be contained (if not eliminated, which is freaking hard to do sometimes. IE I'm looking at you).

Here are some better concrete code examples of event delegation:

Android: converting String to int

// Convert String to Integer

// String s = "fred";  // use this if you want to test the exception below


String s = "100"; 
try
{
  // the String to int conversion happens here
  int i = Integer.parseInt(s.trim());

  // print out the value after the conversion
  System.out.println("int i = " + i);
}
catch (NumberFormatException nfe)
{
  System.out.println("NumberFormatException: " + nfe.getMessage());
}

Getting a 'source: not found' error when using source in a bash script

In the POSIX standard, which /bin/sh is supposed to respect, the command is . (a single dot), not source. The source command is a csh-ism that has been pulled into bash.

Try

. $env_name/bin/activate

Or if you must have non-POSIX bash-isms in your code, use #!/bin/bash.

Java JDBC connection status

You also can use

public boolean isDbConnected(Connection con) {
    try {
        return con != null && !con.isClosed();
    } catch (SQLException ignored) {}

    return false;
}

The program can't start because cygwin1.dll is missing... in Eclipse CDT

You can compile with either Cygwin's g++ or MinGW (via stand-alone or using Cygwin package). However, in order to run it, you need to add the Cygwin1.dll (and others) PATH to the system Windows PATH, before any cygwin style paths.

Thus add: ;C:\cygwin64\bin to the end of your Windows system PATH variable.

Also, to compile for use in CMD or PowerShell, you may need to use: 

x86_64-w64-mingw32-g++.exe -static -std=c++11 prog_name.cc -o prog_name.exe

(This invokes the cross-compiler, if installed.)

Is there a difference between "==" and "is"?

As the other people in this post answer the question in details the difference between == and is for comparing Objects or variables, I would emphasize mainly the comparison between is and == for strings which can give different results and I would urge programmers to carefully use them.

For string comparison, make sure to use == instead of is:

str = 'hello'
if (str is 'hello'):
    print ('str is hello')
if (str == 'hello'):
    print ('str == hello')

Out:

str is hello
str == hello

But in the below example == and is will get different results:

str2 = 'hello sam'
    if (str2 is 'hello sam'):
        print ('str2 is hello sam')
    if (str2 == 'hello sam'):
        print ('str2 == hello sam')

Out:

str2 == hello sam

Conclusion and Analysis:

Use is carefully to compare between strings. Since is for comparing objects and since in Python 3+ every variable such as string interpret as an object, let's see what happened in above paragraphs.

In python there is id function that shows a unique constant of an object during its lifetime. This id is using in back-end of Python interpreter to compare two objects using is keyword.

str = 'hello'
id('hello')
> 140039832615152
id(str)
> 140039832615152

But

str2 = 'hello sam'
id('hello sam')
> 140039832615536
id(str2)
> 140039832615792

How do I compare two strings in python?

If you want a really simple answer:

s_1 = "abc def ghi"
s_2 = "def ghi abc"
flag = 0
for i in s_1:
    if i not in s_2:
        flag = 1
if flag == 0:
    print("a == b")
else:
    print("a != b")

How do I prevent CSS inheritance?

For example if you have two div in XHTML document.

<div id='div1'>
    <p>hello, how are you?</p>
    <div id='div2'>
        <p>I am fine, thank you.</p>
    </div>
</div>

Then try this in CSS.

#div1 > #div2 > p{
    color: red;
}

affect only 'div2' paragraph.

#div1 > p {
    color: red;
}

affect only 'div1' paragraph.

How to get line count of a large file cheaply in Python?

A lot of answers already, but unfortunately most of them are just tiny economies on a barely optimizable problem...

I worked on several projects where line count was the core function of the software, and working as fast as possible with a huge number of files was of paramount importance.

The main bottleneck with line count is I/O access, as you need to read each line in order to detect the line return character, there is simply no way around. The second potential bottleneck is memory management: the more you load at once, the faster you can process, but this bottleneck is negligible compared to the first.

Hence, there are 3 major ways to reduce the processing time of a line count function, apart from tiny optimizations such as disabling gc collection and other micro-managing tricks:

  1. Hardware solution: the major and most obvious way is non-programmatic: buy a very fast SSD/flash hard drive. By far, this is how you can get the biggest speed boosts.

  2. Data preparation solution: if you generate or can modify how the files you process are generated, or if it's acceptable that you can pre-process them, first convert the line return to unix style (\n) as this will save 1 character compared to Windows or MacOS styles (not a big save but it's an easy gain), and secondly and most importantly, you can potentially write lines of fixed length. If you need variable length, you can always pad smaller lines. This way, you can calculate instantly the number of lines from the total filesize, which is much faster to access. Often, the best solution to a problem is to pre-process it so that it better fits your end purpose.

  3. Parallelization + hardware solution: if you can buy multiple hard disks (and if possible SSD flash disks), then you can even go beyond the speed of one disk by leveraging parallelization, by storing your files in a balanced way (easiest is to balance by total size) among disks, and then read in parallel from all those disks. Then, you can expect to get a multiplier boost in proportion with the number of disks you have. If buying multiple disks is not an option for you, then parallelization likely won't help (except if your disk has multiple reading headers like some professional-grade disks, but even then the disk's internal cache memory and PCB circuitry will likely be a bottleneck and prevent you from fully using all heads in parallel, plus you have to devise a specific code for this hard drive you'll use because you need to know the exact cluster mapping so that you store your files on clusters under different heads, and so that you can read them with different heads after). Indeed, it's commonly known that sequential reading is almost always faster than random reading, and parallelization on a single disk will have a performance more similar to random reading than sequential reading (you can test your hard drive speed in both aspects using CrystalDiskMark for example).

If none of those are an option, then you can only rely on micro-managing tricks to improve by a few percents the speed of your line counting function, but don't expect anything really significant. Rather, you can expect the time you'll spend tweaking will be disproportionated compared to the returns in speed improvement you'll see.

HTML5: Slider with two inputs possible?

Sure you can simply use two sliders overlaying each other and add a bit of javascript (actually not more than 5 lines) that the selectors are not exceeding the min/max values (like in @Garys) solution.

Attached you'll find a short snippet adapted from a current project including some CSS3 styling to show what you can do (webkit only). I also added some labels to display the selected values.

It uses JQuery but a vanillajs version is no magic though.

@Update: The code below was just a proof of concept. Due to many requests I've added a possible solution for Mozilla Firefox (without changing the original code). You may want to refractor the code below before using it.

_x000D_
_x000D_ 
    (function() {

        function addSeparator(nStr) {
            nStr += '';
            var x = nStr.split('.');
            var x1 = x[0];
            var x2 = x.length > 1 ? '.' + x[1] : '';
            var rgx = /(\d+)(\d{3})/;
            while (rgx.test(x1)) {
                x1 = x1.replace(rgx, '$1' + '.' + '$2');
            }
            return x1 + x2;
        }

        function rangeInputChangeEventHandler(e){
            var rangeGroup = $(this).attr('name'),
                minBtn = $(this).parent().children('.min'),
                maxBtn = $(this).parent().children('.max'),
                range_min = $(this).parent().children('.range_min'),
                range_max = $(this).parent().children('.range_max'),
                minVal = parseInt($(minBtn).val()),
                maxVal = parseInt($(maxBtn).val()),
                origin = $(this).context.className;

            if(origin === 'min' && minVal > maxVal-5){
                $(minBtn).val(maxVal-5);
            }
            var minVal = parseInt($(minBtn).val());
            $(range_min).html(addSeparator(minVal*1000) + ' €');


            if(origin === 'max' && maxVal-5 < minVal){
                $(maxBtn).val(5+ minVal);
            }
            var maxVal = parseInt($(maxBtn).val());
            $(range_max).html(addSeparator(maxVal*1000) + ' €');
        }

     $('input[type="range"]').on( 'input', rangeInputChangeEventHandler);
})();
_x000D_ 
body{
font-family: sans-serif;
font-size:14px;
}
input[type='range'] {
  width: 210px;
  height: 30px;
  overflow: hidden;
  cursor: pointer;
    outline: none;
}
input[type='range'],
input[type='range']::-webkit-slider-runnable-track,
input[type='range']::-webkit-slider-thumb {
  -webkit-appearance: none;
    background: none;
}
input[type='range']::-webkit-slider-runnable-track {
  width: 200px;
  height: 1px;
  background: #003D7C;
}

input[type='range']:nth-child(2)::-webkit-slider-runnable-track{
  background: none;
}

input[type='range']::-webkit-slider-thumb {
  position: relative;
  height: 15px;
  width: 15px;
  margin-top: -7px;
  background: #fff;
  border: 1px solid #003D7C;
  border-radius: 25px;
  z-index: 1;
}


input[type='range']:nth-child(1)::-webkit-slider-thumb{
  z-index: 2;
}

.rangeslider{
    position: relative;
    height: 60px;
    width: 210px;
    display: inline-block;
    margin-top: -5px;
    margin-left: 20px;
}
.rangeslider input{
    position: absolute;
}
.rangeslider{
    position: absolute;
}

.rangeslider span{
    position: absolute;
    margin-top: 30px;
    left: 0;
}

.rangeslider .right{
   position: relative;
   float: right;
   margin-right: -5px;
}


/* Proof of concept for Firefox */
@-moz-document url-prefix() {
  .rangeslider::before{
    content:'';
    width:100%;
    height:2px;
    background: #003D7C;
    display:block;
    position: relative;
    top:16px;
  }

  input[type='range']:nth-child(1){
    position:absolute;
    top:35px !important;
    overflow:visible !important;
    height:0;
  }

  input[type='range']:nth-child(2){
    position:absolute;
    top:35px !important;
    overflow:visible !important;
    height:0;
  }
input[type='range']::-moz-range-thumb {
  position: relative;
  height: 15px;
  width: 15px;
  margin-top: -7px;
  background: #fff;
  border: 1px solid #003D7C;
  border-radius: 25px;
  z-index: 1;
}

  input[type='range']:nth-child(1)::-moz-range-thumb {
      transform: translateY(-20px);    
  }
  input[type='range']:nth-child(2)::-moz-range-thumb {
      transform: translateY(-20px);    
  }
}
_x000D_ 
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<div class="rangeslider">
                                <input class="min" name="range_1" type="range" min="1" max="100" value="10" />
                                <input class="max" name="range_1" type="range" min="1" max="100" value="90" />
                                <span class="range_min light left">10.000 €</span>
                                <span class="range_max light right">90.000 €</span>
                            </div>
_x000D_
_x000D_
_x000D_

How do I update Node.js?

405 method not allowed Web API

check in your project .csproj file and change 

<IISUrl>http://localhost:PORT/</IISUrl>

to your website url like this

<IISUrl>http://example.com:applicationName/</IISUrl>

How can I submit a POST form using the <a href="..."> tag?

No JavaScript needed if you use a button instead:

<form action="your_url" method="post">
    <button type="submit" name="your_name" value="your_value" class="btn-link">Go</button>
</form>

You can style a button to look like a link, for example:

.btn-link {
    border: none;
    outline: none;
    background: none;
    cursor: pointer;
    color: #0000EE;
    padding: 0;
    text-decoration: underline;
    font-family: inherit;
    font-size: inherit;
}

Select DataFrame rows between two dates

With my testing of pandas version 0.22.0 you can now answer this question easier with more readable code by simply using between.

# create a single column DataFrame with dates going from Jan 1st 2018 to Jan 1st 2019
df = pd.DataFrame({'dates':pd.date_range('2018-01-01','2019-01-01')})

Let's say you want to grab the dates between Nov 27th 2018 and Jan 15th 2019:

# use the between statement to get a boolean mask
df['dates'].between('2018-11-27','2019-01-15', inclusive=False)

0    False
1    False
2    False
3    False
4    False

# you can pass this boolean mask straight to loc
df.loc[df['dates'].between('2018-11-27','2019-01-15', inclusive=False)]

    dates
331 2018-11-28
332 2018-11-29
333 2018-11-30
334 2018-12-01
335 2018-12-02

Notice the inclusive argument. very helpful when you want to be explicit about your range. notice when set to True we return Nov 27th of 2018 as well:

df.loc[df['dates'].between('2018-11-27','2019-01-15', inclusive=True)]

    dates
330 2018-11-27
331 2018-11-28
332 2018-11-29
333 2018-11-30
334 2018-12-01

This method is also faster than the previously mentioned isin method:

%%timeit -n 5
df.loc[df['dates'].between('2018-11-27','2019-01-15', inclusive=True)]
868 µs ± 164 µs per loop (mean ± std. dev. of 7 runs, 5 loops each)


%%timeit -n 5

df.loc[df['dates'].isin(pd.date_range('2018-01-01','2019-01-01'))]
1.53 ms ± 305 µs per loop (mean ± std. dev. of 7 runs, 5 loops each)

However, it is not faster than the currently accepted answer, provided by unutbu, only if the mask is already created. but if the mask is dynamic and needs to be reassigned over and over, my method may be more efficient:

# already create the mask THEN time the function

start_date = dt.datetime(2018,11,27)
end_date = dt.datetime(2019,1,15)
mask = (df['dates'] > start_date) & (df['dates'] <= end_date)

%%timeit -n 5
df.loc[mask]
191 µs ± 28.5 µs per loop (mean ± std. dev. of 7 runs, 5 loops each)

iterating through Enumeration of hastable keys throws NoSuchElementException error

You call nextElement() twice in your loop. This call moves the enumeration pointer forward. You should modify your code like the following:

while (e.hasMoreElements()) {
    String param = e.nextElement();
    System.out.println(param);
}

Why the switch statement cannot be applied on strings?

Late to the party, here's a solution I came up with some time ago, which completely abides to the requested syntax.

#include <uberswitch/uberswitch.hpp>

int main()
{
    uberswitch (std::string("raj"))
    {
        case ("sda"): /* ... */ break;  //notice the parenthesis around the value.
    }
}

Here's the code: https://github.com/falemagn/uberswitch

Difference between JPanel, JFrame, JComponent, and JApplet

Those classes are common extension points for Java UI designs. First off, realize that they don't necessarily have much to do with each other directly, so trying to find a relationship between them might be counterproductive.

JApplet - A base class that let's you write code that will run within the context of a browser, like for an interactive web page. This is cool and all but it brings limitations which is the price for it playing nice in the real world. Normally JApplet is used when you want to have your own UI in a web page. I've always wondered why people don't take advantage of applets to store state for a session so no database or cookies are needed.

JComponent - A base class for objects which intend to interact with Swing.

JFrame - Used to represent the stuff a window should have. This includes borders (resizeable y/n?), titlebar (App name or other message), controls (minimize/maximize allowed?), and event handlers for various system events like 'window close' (permit app to exit yet?).

JPanel - Generic class used to gather other elements together. This is more important with working with the visual layout or one of the provided layout managers e.g. gridbaglayout, etc. For example, you have a textbox that is bigger then the area you have reserved. Put the textbox in a scrolling pane and put that pane into a JPanel. Then when you place the JPanel, it will be more manageable in terms of layout.

Peak memory usage of a linux/unix process

Valgrind one-liner:

valgrind --tool=massif --pages-as-heap=yes --massif-out-file=massif.out ./test.sh; grep mem_heap_B massif.out | sed -e 's/mem_heap_B=\(.*\)/\1/' | sort -g | tail -n 1

Note use of --pages-as-heap to measure all memory in a process. More info here: http://valgrind.org/docs/manual/ms-manual.html

This will slow down your command significantly.

How to convert a time string to seconds?

without imports

time = "01:34:11"
sum(x * int(t) for x, t in zip([3600, 60, 1], time.split(":")))

How do you open a file in C++?

You need to use an ifstream if you just want to read (use an ofstream to write, or an fstream for both).

To open a file in text mode, do the following:

ifstream in("filename.ext", ios_base::in); // the in flag is optional

To open a file in binary mode, you just need to add the "binary" flag.

ifstream in2("filename2.ext", ios_base::in | ios_base::binary );

Use the ifstream.read() function to read a block of characters (in binary or text mode). Use the getline() function (it's global) to read an entire line.

How can I create a product key for my C# application?

I'm going to piggyback a bit on @frankodwyer's great answer and dig a little deeper into online-based licensing. I'm the founder of Keygen, a licensing REST API built for developers.

Since you mentioned wanting 2 "types" of licenses for your application, i.e. a "full version" and a "trial version", we can simplify that and use a feature license model where you license specific features of your application (in this case, there's a "full" feature-set and a "trial" feature-set).

To start off, we could create 2 license types (called policies in Keygen) and whenever a user registers an account you can generate a "trial" license for them to start out (the "trial" license implements our "trial" feature policy), which you can use to do various checks within the app e.g. can user use Trial-Feature-A and Trial-Feature-B.

And building on that, whenever a user purchases your app (whether you're using PayPal, Stripe, etc.), you can generate a license implementing the "full" feature policy and associate it with the user's account. Now within your app you can check if the user has a "full" license that can do Pro-Feature-X and Pro-Feature-Y (by doing something like user.HasLicenseFor(FEATURE_POLICY_ID)).

I mentioned allowing your users to create user accounts—what do I mean by that? I've gone into this in detail in a couple other answers, but a quick rundown as to why I think this is a superior way to authenticate and identify your users:

  1. User accounts let you associate multiple licenses and multiple machines to a single user, giving you insight into your customer's behavior and to prompt them for "in-app purchases" i.e. purchasing your "full" version (kind of like mobile apps).
  2. We shouldn't require our customers to input long license keys, which are both tedious to input and hard to keep track of i.e. they get lost easily. (Try searching "lost license key" on Twitter!)
  3. Customers are accustomed to using an email/password; I think we should do what people are used to doing so that we can provide a good user experience (UX).

Of course, if you don't want to handle user accounts and you want your users to input license keys, that's completely fine (and Keygen supports doing that as well). I'm just offering another way to go about handling that aspect of licensing and hopefully provide a nice UX for your customers.

Finally since you also mentioned that you want to update these licenses annually, you can set a duration on your policies so that "full" licenses will expire after a year and "trial" licenses last say 2 weeks, requiring that your users purchase a new license after expiration.

I could dig in more, getting into associating machines with users and things like that, but I thought I'd try to keep this answer short and focus on simply licensing features to your users.

Using CMake with GNU Make: How can I see the exact commands?

When you run make, add VERBOSE=1 to see the full command output. For example:

cmake .
make VERBOSE=1

Or you can add -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON to the cmake command for permanent verbose command output from the generated Makefiles.

cmake -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .
make

To reduce some possibly less-interesting output you might like to use the following options. The option CMAKE_RULE_MESSAGES=OFF removes lines like [ 33%] Building C object..., while --no-print-directory tells make to not print out the current directory filtering out lines like make[1]: Entering directory and make[1]: Leaving directory.

cmake -DCMAKE_RULE_MESSAGES:BOOL=OFF -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .
make --no-print-directory

What is the difference between the remap, noremap, nnoremap and vnoremap mapping commands in Vim?

One difference is that:

  • :map does nvo == normal + (visual + select) + operator pending
  • :map! does ic == insert + command-line mode

as stated on help map-modes tables.

So: map does not map to all modes.

To map to all modes you need both :map and :map!.

How can a LEFT OUTER JOIN return more records than exist in the left table?

It isn't impossible. The number of records in the left table is the minimum number of records it will return. If the right table has two records that match to one record in the left table, it will return two records.

MySQL select all rows from last month until (now() - 1 month), for comparative purposes

 
SELECT * 
FROM table 
WHERE date BETWEEN 
    ADDDATE(LAST_DAY(DATE_SUB(NOW(),INTERVAL 2 MONTH)), INTERVAL 1 DAY) 
    AND DATE_SUB(NOW(),INTERVAL 1 MONTH);

See the docs for info on DATE_SUB, ADDDATE, LAST_DAY and other useful datetime functions.

Taskkill /f doesn't kill a process

If taskkill /F /T /PID <pid> does not work. Try opening your terminal elevated using Run as Administrator.

Search cmd in your windows menu, and right click Run as Administrator, then run the command again. This worked for me.

How do I use this JavaScript variable in HTML?

You can create a <p> element:

_x000D_
_x000D_ 
<!DOCTYPE html>_x000D_
<html>_x000D_
  <script>_x000D_
  var name = prompt("What's your name?");_x000D_
  var lengthOfName = name.length_x000D_
  p = document.createElement("p");_x000D_
  p.innerHTML = "Your name is "+lengthOfName+" characters long.";_x000D_
  document.body.appendChild(p);_x000D_
  </script>_x000D_
  <body>_x000D_
  </body>_x000D_
  </html>
_x000D_
_x000D_
_x000D_

Push existing project into Github

 
git init
git add .
git commit -m "Initial commit"
git remote add origin <project url>
git push -f origin master

The -f option on git push forces the push. If you don't use it, you'll see an error like this:

To [email protected]:roseperrone/project.git
 ! [rejected]        master -> master (fetch first)
error: failed to push some refs to '[email protected]:roseperrone/project.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first merge the remote changes (e.g.,
hint: 'git pull') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

What is a stack trace, and how can I use it to debug my application errors?

There is one more stacktrace feature offered by Throwable family - the possibility to manipulate stack trace information.

Standard behavior:

package test.stack.trace;

public class SomeClass {

    public void methodA() {
        methodB();
    }

    public void methodB() {
        methodC();
    }

    public void methodC() {
        throw new RuntimeException();
    }

    public static void main(String[] args) {
        new SomeClass().methodA();
    }
}

Stack trace:

Exception in thread "main" java.lang.RuntimeException
    at test.stack.trace.SomeClass.methodC(SomeClass.java:18)
    at test.stack.trace.SomeClass.methodB(SomeClass.java:13)
    at test.stack.trace.SomeClass.methodA(SomeClass.java:9)
    at test.stack.trace.SomeClass.main(SomeClass.java:27)

Manipulated stack trace:

package test.stack.trace;

public class SomeClass {

    ...

    public void methodC() {
        RuntimeException e = new RuntimeException();
        e.setStackTrace(new StackTraceElement[]{
                new StackTraceElement("OtherClass", "methodX", "String.java", 99),
                new StackTraceElement("OtherClass", "methodY", "String.java", 55)
        });
        throw e;
    }

    public static void main(String[] args) {
        new SomeClass().methodA();
    }
}

Stack trace:

Exception in thread "main" java.lang.RuntimeException
    at OtherClass.methodX(String.java:99)
    at OtherClass.methodY(String.java:55)

Printing HashMap In Java

To print both key and value, use the following:

for (Object objectName : example.keySet()) {
   System.out.println(objectName);
   System.out.println(example.get(objectName));
 }

How do I access ViewBag from JS

You can achieve the solution, by doing this:

JavaScript:

var myValue = document.getElementById("@(ViewBag.CC)").value;

or if you want to use jQuery, then:

jQuery

var myValue = $('#' + '@(ViewBag.CC)').val();

Test for non-zero length string in Bash: [ -n "$var" ] or [ "$var" ]

It is better to use the more powerful [[ as far as Bash is concerned.

Usual cases

if [[ $var ]]; then   # var is set and it is not empty
if [[ ! $var ]]; then # var is not set or it is set to an empty string

The above two constructs look clean and readable. They should suffice in most cases.

Note that we don't need to quote the variable expansions inside [[ as there is no danger of word splitting and globbing.

To prevent shellcheck's soft complaints about [[ $var ]] and [[ ! $var ]], we could use the -n option.

Rare cases

In the rare case of us having to make a distinction between "being set to an empty string" vs "not being set at all", we could use these:

if [[ ${var+x} ]]; then           # var is set but it could be empty
if [[ ! ${var+x} ]]; then         # var is not set
if [[ ${var+x} && ! $var ]]; then # var is set and is empty

We can also use the -v test:

if [[ -v var ]]; then             # var is set but it could be empty
if [[ ! -v var ]]; then           # var is not set
if [[ -v var && ! $var ]]; then   # var is set and is empty
if [[ -v var && -z $var ]]; then  # var is set and is empty

Related posts and documentation

There are a plenty of posts related to this topic. Here are a few:

Python initializing a list of lists

The problem is that they're all the same exact list in memory. When you use the [x]*n syntax, what you get is a list of n many x objects, but they're all references to the same object. They're not distinct instances, rather, just n references to the same instance.

To make a list of 3 different lists, do this:

x = [[] for i in range(3)]

This gives you 3 separate instances of [], which is what you want

[[]]*n is similar to

l = []
x = []
for i in range(n):
    x.append(l)

While [[] for i in range(3)] is similar to:

x = []
for i in range(n):
    x.append([])   # appending a new list!

In [20]: x = [[]] * 4

In [21]: [id(i) for i in x]
Out[21]: [164363948, 164363948, 164363948, 164363948] # same id()'s for each list,i.e same object


In [22]: x=[[] for i in range(4)]

In [23]: [id(i) for i in x]
Out[23]: [164382060, 164364140, 164363628, 164381292] #different id(), i.e unique objects this time

Is PowerShell ready to replace my Cygwin shell on Windows?

I haven't seen that the PowerShell has really taken off, at least not yet. So it might not be worth the effort of learning it unless those others on your team already know it.

For your predicament you might be better off with a scripting language that others could get behind, Perl like you mentioned, or others like Ruby or Python.

I think a lot of it depends on what you need to do. Personally I've been using Python for my own personal scripts, but I know when I start writing something that I'll never be able to pass it on - so I try not to do anything too revolutionary.

Find duplicate characters in a String and count the number of occurances using Java

You can also achieve it by iterating over your String and using a switch to check each individual character, adding a counter whenever it finds a match. Ah, maybe some code will make it clearer:

Main Application:

public static void main(String[] args) {

        String test = "The quick brown fox jumped over the lazy dog.";

        int countA = 0, countO = 0, countSpace = 0, countDot = 0;

        for (int i = 0; i < test.length(); i++) {
            switch (test.charAt(i)) {
                case 'a':
                case 'A': countA++; break;
                case 'o':
                case 'O': countO++; break;
                case ' ': countSpace++; break;
                case '.': countDot++; break;
            }
        }

        System.out.printf("%s%d%n%s%d%n%s%d%n%s%d", "A: ", countA, "O: ", countO, "Space: ", countSpace, "Dot: ", countDot);

    }

Output:

A: 1
O: 4
Space: 8
Dot: 1

Alternative to google finance api

Updating answer a bit

1. Try Twelve Data API

For beginners try to run the following query with a JSON response:

https://api.twelvedata.com/time_series?symbol=AAPL&interval=1min&apikey=demo&source=docs

NO more real time Alpha Vantage API

For beginners you can try to get a JSON output from query such as

https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=MSFT&apikey=demo

DON'T Try Yahoo Finance API (it is DEPRECATED or UNAVAILABLE NOW).

For beginners, you can generate a CSV with a simple API call:

http://finance.yahoo.com/d/quotes.csv?s=AAPL+GOOG+MSFT&f=sb2b3jk

(This will generate and save a CSV for AAPL, GOOG, and MSFT)

Note that you must append the format to the query string (f=..). For an overview of all of the formats see this page.

For more examples, visit this page.

For XML and JSON-based data, you can do the following:

Don't use YQL (Yahoo Query Language)

For example:

http://developer.yahoo.com/yql/console/?q=select%20*%20from%20yahoo.finance
.quotes%20where%20symbol%20in%20(%22YHOO%22%2C%22AAPL%22%2C%22GOOG%22%2C%22
MSFT%22)%0A%09%09&env=http%3A%2F%2Fdatatables.org%2Falltables.env

2. Use the webservice

For example, to get all stock quotes in XML:

http://finance.yahoo.com/webservice/v1/symbols/allcurrencies/quote

To get all stock quotes in JSON, just add format=JSON to the end of the URL:

http://finance.yahoo.com/webservice/v1/symbols/allcurrencies/quote?format=json

Alternatives:

  1. Currency API

    • 165+ real time currency rates, including few cryptos. Docs here.

  2. Financial Content API

  3. IEX

  4. Open Exchange Rates

  5. Polygon

  6. XE API

  7. Xignite API

  8. currencylayer API

  9. Other APIs - discussed at programmableWeb

Difference between <context:annotation-config> and <context:component-scan>

<context:annotation-config>:

This tells Spring that I am going to use Annotated beans as spring bean and those would be wired through @Autowired annotation, instead of declaring in spring config xml file.

<context:component-scan base-package="com.test..."> :

This tells Spring container, where to start searching those annotated beans. Here spring will search all sub packages of the base package.

Redirecting Output from within Batch file

 
@echo off
>output.txt (
echo Checking your system infor, Please wating...

systeminfo | findstr /c:"Host Name" 
systeminfo | findstr /c:"Domain"

ipconfig /all | find "Physical Address" 

ipconfig | find "IPv4" 
ipconfig | find "Default Gateway"

)

@pause

Can you have multiline HTML5 placeholder text in a <textarea>?

On most (see details below) browsers, editing the placeholder in javascript allows multiline placeholder. As it has been said, it's not compliant with the specification and you shouldn't expect it to work in the future (edit: it does work).

This example replaces all multiline textarea's placeholder.

_x000D_
_x000D_ 
var textAreas = document.getElementsByTagName('textarea');

Array.prototype.forEach.call(textAreas, function(elem) {
    elem.placeholder = elem.placeholder.replace(/\\n/g, '\n');
});
_x000D_ 
<textarea class="textAreaMultiline" 
          placeholder="Hello, \nThis is multiline example \n\nHave Fun"
          rows="5" cols="35"></textarea>
_x000D_
_x000D_
_x000D_

JsFiddle snippet.

Expected result

Expected result

Based on comments it seems some browser accepts this hack and others don't.
This is the results of tests I ran (with browsertshots and browserstack)

  • Chrome: >= 35.0.1916.69
  • Firefox: >= 35.0 (results varies on platform)
  • IE: >= 10
  • KHTML based browsers: 4.8
  • Safari: No (tested = Safari 8.0.6 Mac OS X 10.8)
  • Opera: No (tested <= 15.0.1147.72)

Fused with theses statistics, this means that it works on about 88.7% of currently (Oct 2015) used browsers.

Update: Today, it works on at least 94.4% of currently (July 2018) used browsers.

WCF on IIS8; *.svc handler mapping doesn't work

Windows 8 with IIS8

  • Hit Windows+X
  • Select Programs and Features (first item on list)
  • Select Turn Windows Features on or off on the left
  • Expand .NET Framework 4.5 Advanced Services
  • Expand WCF Services
  • Enable HTTP Activation

TypeScript - Append HTML to container element in Angular 2

When working with Angular the recent update to Angular 8 introduced that a static property inside @ViewChild() is required as stated here and here. Then your code would require this small change:

@ViewChild('one') d1:ElementRef;

into

// query results available in ngOnInit
@ViewChild('one', {static: true}) foo: ElementRef;

OR

// query results available in ngAfterViewInit
@ViewChild('one', {static: false}) foo: ElementRef;

Java foreach loop: for (Integer i : list) { ... }

Another way, you can use a pass-through object to capture the last value and then do something with it:

List<Integer> list = new ArrayList<Integer>();
Integer lastValue = null;
for (Integer i : list) {
    // do stuff
    lastValue = i;
}
// do stuff with last value

Android: Go back to previous activity

 
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

This will get you to a previous activity keeping its stack and clearing all activities after it from the stack.

For example, if stack was A->B->C->D and you start B with this flag, stack will be A->B

Difference between using Throwable and Exception in a try catch

Thowable catches really everything even ThreadDeath which gets thrown by default to stop a thread from the now deprecated Thread.stop() method. So by catching Throwable you can be sure that you'll never leave the try block without at least going through your catch block, but you should be prepared to also handle OutOfMemoryError and InternalError or StackOverflowError.

Catching Throwable is most useful for outer server loops that delegate all sorts of requests to outside code but may itself never terminate to keep the service alive.

Cloning an Object in Node.js

You can prototype object and then call object instance every time you want to use and change object:

function object () {
  this.x = 5;
  this.y = 5;
}
var obj1 = new object();
var obj2 = new object();
obj2.x = 6;
console.log(obj1.x); //logs 5

You can also pass arguments to object constructor

function object (x, y) {
   this.x = x;
   this.y = y;
}
var obj1 = new object(5, 5);
var obj2 = new object(6, 6);
console.log(obj1.x); //logs 5
console.log(obj2.x); //logs 6

Hope this is helpful.

How can I uninstall Ruby on ubuntu?

Here is what sudo apt-get purge ruby* removed relating to GRUB for me:

grub-pc 
grub-gfxpayload-lists
grub2-common
grub-pc-bin 
grub-common

What is the size of ActionBar in pixels?

If you are using ActionBarSherlock, you can get the height with

@dimen/abs__action_bar_default_height

The representation of if-elseif-else in EL using JSF

You can use "ELSE IF" using conditional operator in expression language as below: 

 <p:outputLabel value="#{transaction.status.equals('PNDNG')?'Pending':
                                     transaction.status.equals('RJCTD')?'Rejected':
                                     transaction.status.equals('CNFRMD')?'Confirmed':
                                     transaction.status.equals('PSTD')?'Posted':''}"/>

How to encode a URL in Swift

Swift 3:

let escapedString = originalString.addingPercentEncoding(withAllowedCharacters:NSCharacterSet.urlQueryAllowed)

Update TextView Every Second

Extending @endian 's answer, you could use a thread and call a method to update the TextView. Below is some code I made up on the spot.

java.util.Date noteTS;
String time, date;
TextView tvTime, tvDate;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.deskclock);

    tvTime = (TextView) findViewById(R.id.tvTime);
    tvDate = (TextView) findViewById(R.id.tvDate);

    Thread t = new Thread() {

        @Override
        public void run() {
            try {
                while (!isInterrupted()) {
                    Thread.sleep(1000);
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            updateTextView();
                        }
                    });
                }
            } catch (InterruptedException e) {
            }
        }
    };

    t.start();
}

private void updateTextView() {
    noteTS = Calendar.getInstance().getTime();

    String time = "hh:mm"; // 12:00
    tvTime.setText(DateFormat.format(time, noteTS));

    String date = "dd MMMMM yyyy"; // 01 January 2013
    tvDate.setText(DateFormat.format(date, noteTS));
}

Reading data from a website using C#

If you're downloading text then I'd recommend using the WebClient and get a streamreader to the text:

        WebClient web = new WebClient();
        System.IO.Stream stream = web.OpenRead("http://www.yoursite.com/resource.txt");
        using (System.IO.StreamReader reader = new System.IO.StreamReader(stream))
        {
            String text = reader.ReadToEnd();
        }

If this is taking a long time then it is probably a network issue or a problem on the web server. Try opening the resource in a browser and see how long that takes. If the webpage is very large, you may want to look at streaming it in chunks rather than reading all the way to the end as in that example. Look at http://msdn.microsoft.com/en-us/library/system.io.stream.read.aspx to see how to read from a stream.

How to center a table of the screen (vertically and horizontally)

I tried above align attribute in HTML5. It is not supported. Also I tried flex-align and vertival-align with style attributes. Still not able to place TABLE in center of screen. The following style place table in center horizontally.

style="margin:auto;"