Programs & Examples On #Unmanaged memory

How can I increase a scrollbar's width using CSS?

You can stablish specific toolbar for div

div::-webkit-scrollbar {
width: 12px;

div::-webkit-scrollbar-track {
-webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3);
border-radius: 10px;

see demo in

How to delete duplicate rows in SQL Server?

with myCTE

select productName,ROW_NUMBER() over(PARTITION BY productName order by slno) as Duplicate from productDetails
Delete from myCTE where Duplicate>1

ESLint not working in VS Code?

configuring working directories solved it for me, since I had multiple projects with own .eslintrc files openend in the same window.

Put this in your .vscode/settings.json

"eslint.workingDirectories": [

thanks to this guy on github:

PS: useful command to list all subdirectories containing an .eslintrc except /node_modules:

find . .eslintrc | grep .eslintrc | grep -v node_modules

How to select min and max values of a column in a datatable?

var min = dt.AsEnumerable().Min(row => row["AccountLevel"]);
var max = dt.AsEnumerable().Max(row => row["AccountLevel"]);

Performing a Stress Test on Web Application?

We recently started using Gatling for load testing. I would highly recommend to try out this tool for load testing. We had used SOASTA and JMETER in past. Our main reason to consider Gatling is following:

  • Recorder to record the scenario
  • Using Akka and Netty which gives better performance compare to Jmeter Threading model
  • DSL Scala which is very much maintainable compare to Jmeter XML
  • Easy to write the tests, don't scare if it's scala.
  • Reporting

Let me give you simple example to write the code using Gatling Code:

// your code starts here  
val scn = scenario("Scenario")  
// injecting 100 user enter code here's on above scenario.   

However you can make it as complicated as possible. One of the feature which stand out for Gatling is reporting which is very detail.

Here are some links:
Gatling Tutorial

I recently gave talk on it, you can go through the talk here:

How can I rollback an UPDATE query in SQL server 2005?



It usually works

Proper way to return JSON using node or Express

That response is a string too, if you want to send the response prettified, for some awkward reason, you could use something like JSON.stringify(anObject, null, 3)

It's important that you set the Content-Type header to application/json, too.

var http = require('http');

var app = http.createServer(function(req,res){
    res.setHeader('Content-Type', 'application/json');
    res.end(JSON.stringify({ a: 1 }));

// > {"a":1}


var http = require('http');

var app = http.createServer(function(req,res){
    res.setHeader('Content-Type', 'application/json');
    res.end(JSON.stringify({ a: 1 }, null, 3));

// >  {
// >     "a": 1
// >  }

I'm not exactly sure why you want to terminate it with a newline, but you could just do JSON.stringify(...) + '\n' to achieve that.


In express you can do this by changing the options instead.

'json replacer' JSON replacer callback, null by default

'json spaces' JSON response spaces for formatting, defaults to 2 in development, 0 in production

Not actually recommended to set to 40

app.set('json spaces', 40);

Then you could just respond with some json.

res.json({ a: 1 });

It'll use the 'json spaces' configuration to prettify it.

Perl - If string contains text?

For case-insensitive string search, use index (or rindex) in combination with fc. This example expands on the answer by Eugene Yarmash:

use feature qw( fc ); 
my $str = "Abc"; 
my $substr = "aB"; 

print "found" if index( fc $str, fc $substr ) != -1;
# Prints: found

print "found" if rindex( fc $str, fc $substr ) != -1;
# Prints: found

$str = "Abc";
$substr = "bA";

print "found" if index( fc $str, fc $substr ) != -1;
# Prints nothing

print "found" if rindex( fc $str, fc $substr ) != -1;
# Prints nothing

Both index and rindex return -1 if the substring is not found.
And fc returns a casefolded version of its string argument, and should be used here instead of the (more familiar) uc or lc. Remember to enable this function, for example with use feature qw( fc );.

How do I make a batch file terminate upon encountering an error?

Check the errorlevel in an if statement, and then exit /b (exit the batch file only, not the entire cmd.exe process) for values other than 0.

same-executable-over-and-over.exe /with different "parameters"
if %errorlevel% neq 0 exit /b %errorlevel%

If you want the value of the errorlevel to propagate outside of your batch file

if %errorlevel% neq 0 exit /b %errorlevel%

but if this is inside a for it gets a bit tricky. You'll need something more like:

setlocal enabledelayedexpansion
for %%f in (C:\Windows\*) do (
    same-executable-over-and-over.exe /with different "parameters"
    if !errorlevel! neq 0 exit /b !errorlevel!

Edit: You have to check the error after each command. There's no global "on error goto" type of construct in cmd.exe/ batch. I've also updated my code per CodeMonkey, although I've never encountered a negative errorlevel in any of my batch-hacking on XP or Vista.

Using BufferedReader to read Text File

You read line through while loop and through the loop you read the next line ,so just read it in while loop

 String s;
 while ((s=br.readLine()) != null) {

How to convert const char* to char* in C?

To convert a const char* to char* you could create a function like this :

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char* unconstchar(const char* s) {
      return NULL;
    int i;
    char* res = NULL;
    res = (char*) malloc(strlen(s)+1);
        fprintf(stderr, "Memory Allocation Failed! Exiting...\n");
    } else{
        for (i = 0; s[i] != '\0'; i++) {
            res[i] = s[i];
        res[i] = '\0';
        return res;

int main() {
    const char* s = "this is bikash";
    char* p = unconstchar(s);

Detect user scroll down or scroll up in jQuery

To differentiate between scroll up/down in jQuery, you could use:

var mousewheelevt = (/Firefox/i.test(navigator.userAgent)) ? "DOMMouseScroll" : "mousewheel" //FF doesn't recognize mousewheel as of FF3.x
$('#yourDiv').bind(mousewheelevt, function(e){

    var evt = window.event || e //equalize event object     
    evt = evt.originalEvent ? evt.originalEvent : evt; //convert to originalEvent if possible               
    var delta = evt.detail ? evt.detail*(-40) : evt.wheelDelta //check for detail first, because it is used by Opera and FF

    if(delta > 0) {
        //scroll up
        //scroll down

This method also works in divs that have overflow:hidden.

I successfully tested it in FireFox, IE and Chrome.

Jenkins, specifying JAVA_HOME

Download package rpm package from you can give additional java location like I have default 1.7 java in my system but I am using /opt/jdk1.8.0_60/bin/java for jenkins. Open jenkins startup script /etc/init.d/jenkins and add additional java here, I m case I have added /opt/jdk1.8.0_60/bin/java,

Search usable Java as /usr/bin/java might not point to minimal version required by Jenkins.


candidates=" /opt/jdk1.8.0_60/bin/java

How to use if, else condition in jsf to display image

Instead of using the "c" tags, you could also do the following:

<h:outputLink value="Images/thumb_02.jpg" target="_blank" rendered="#{not empty user or user.userId eq 0}" />
<h:graphicImage value="Images/thumb_02.jpg" rendered="#{not empty user or user.userId eq 0}" />

<h:outputLink value="/DisplayBlobExample?userId=#{user.userId}" target="_blank" rendered="#{not empty user and user.userId neq 0}" />
<h:graphicImage value="/DisplayBlobExample?userId=#{user.userId}" rendered="#{not empty user and user.userId neq 0}"/>

I think that's a little more readable alternative to skuntsel's alternative answer and is utilizing the JSF rendered attribute instead of nesting a ternary operator. And off the answer, did you possibly mean to put your image in between the anchor tags so the image is clickable?

Get full query string in C# ASP.NET

Request.QueryString returns you a collection of Key/Value pairs representing the Query String. Not a String. Don't think that would cause a Object Reference error though. The reason your getting that is because as Mauro pointed out in the comments. It's QueryString and not Querystring.




    string URL = Request.Url.AbsoluteUri 
    System.Net.WebClient wc = new System.Net.WebClient();
    string data = wc.DownloadString(URL);

Same as your code but Request.Url.AbsoluteUri will return the full path, including the query string.

Differences between and websockets

Its advantages are that it simplifies the usage of WebSockets as you described in #2, and probably more importantly it provides fail-overs to other protocols in the event that WebSockets are not supported on the browser or server. I would avoid using WebSockets directly unless you are very familiar with what environments they don't work and you are capable of working around those limitations.

This is a good read on both WebSockets and Socket.IO.

How to export query result to csv in Oracle SQL Developer?

To take an export to your local system from sql developer.

Path : C:\Source_Table_Extract\des_loan_due_dtls_src_boaf.csv

    SPOOL "Path where you want to save the file"

SSRS 2008 R2 - SSRS 2012 - ReportViewer: Reports are blank in Safari and Chrome

Just include SizeToReportContent="true" as shown below

<rsweb:ReportViewer ID="ReportViewer1" runat="server" SizeToReportContent="True"...

Recommended add-ons/plugins for Microsoft Visual Studio

VSCommands 2010

from the website: Latest version supports:

  • Manage Reference Paths
  • Prevent accidental Drag & Drop in Solution Explorer
  • Prevent accidental linked file delete
  • Apply Fix (automatically fix build errors/warnings)
  • Open PowerShell
  • Show Assembly Details
  • Create Code Contract
  • Cancel Build when first project fails
  • Debug Output - custom formatting
  • Build Output - custom formatting
  • Search Output - custom formatting
  • Configure WPF Rendering
  • Configure Fusion Logs
  • Configure IE for debugging
  • Locate Source File
  • Thumbnails in IDE Navigator
  • Extended support for xaml, aspx, css, js and html files
  • Disable Ctrl + Mouse Wheel Zoom
  • Zoom to Mouse Pointer
  • Configurability
  • Attach to local IIS
  • Copy Full Path
  • Build Startup Projects
  • Open Command Prompt
  • Search Online
  • Build Statistics
  • Group linked items
  • Copy/Paste Reference
  • Copy/Paste as Link
  • Collapse Solution
  • Group items directly from user interface (DependantUpon)
  • Open In Expression Blend
  • Locate in Solution
  • Edit Project File
  • Edit Solution File
  • Show All Files

and others, so try it now!

Setting up and using environment variables in IntelliJ Idea

In addition to the above answer and restarting the IDE didn't do, try restarting "Jetbrains Toolbox" if you use it, this did it for me

How to call a SOAP web service on Android

You may perform soap call as post over http with certain headers. I solved this question without additional libraries like ksoap2 Here is live code getting orders from soap service

private static HashMap<String,String> mHeaders = new HashMap<>();

static {
    mHeaders.put("Content-Type", "application/soap+xml");
    mHeaders.put("Host", "");
    mHeaders.put("Connection", "Keep-Alive");
    mHeaders.put("Authorization","Basic Q2xpZW50NTkzMzppMjR3s2U="); // optional
}public final static InputStream receiveCurrentShipments(String stringUrlShipments)
    int status=0;
    String xmlstring= "<soap:Envelope xmlns:soap=\"\" xmlns:ser=\"\">\n" +
            "   <soap:Header/>\n" +
            "   <soap:Body>\n" +
            "      <ser:GetAllOrdersOfShipment>\n" +
            "         <ser:CodeOfBranch></ser:CodeOfBranch>\n" +
            "      </ser:GetAllOrdersOfShipment>\n" +
            "   </soap:Body>\n" +
    StringBuffer chaine = new StringBuffer("");

    HttpURLConnection connection = null;
    try {
        URL url = new URL(stringUrlShipments);
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestProperty("Content-Length", xmlstring.getBytes().length + "");
        connection.setRequestProperty("SOAPAction", "");

        for(Map.Entry<String, String> entry : mHeaders.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();



        OutputStream outputStream = connection.getOutputStream();

        status = connection.getResponseCode();
    } catch (ProtocolException e) {
    } catch (MalformedURLException e) {
    } catch (IOException e) {
    } finally {

        Log.i("HTTP Client", "HTTP status code : " + status);

    InputStream inputStream = null;
    try {
        inputStream = connection.getInputStream();
    } catch (IOException e) {

    return inputStream;

How to enter quotes in a Java string?

suppose ROM is string variable which equals "strval" you can simply do

String value= " \" "+ROM+" \" ";

it will be stored as

value= " "strval" ";    

Find and replace with a newline in Visual Studio Code

With VS Code release 1.38 you can press CTRL + Enter in the editor find box to add a newline character.

enter image description here

With VS Code release 1.30 you can type Shift + Enter in the search box to add a newline character without needing to use regex mode.

enter image description here

Since VS Code release 1.3, the regex find has supported newline characters. To use this feature set the find window to regex mode and use \n as the newline character.

Multiline find in VS Code gif

Object reference not set to an instance of an object.

strSearch in this case is probably null (not simply empty).

Try using


if you are just trying to determine if the string doesn't have any contents.

How to remove item from array by value?


var ary = ['three', 'seven', 'eleven'];
var index = ary.indexOf('seven'); // get index if value found otherwise -1

if (index > -1) { //if found
  ary.splice(index, 1);

Encode a FileStream to base64 with c#

A simple Stream extension method would do the job:

public static class StreamExtensions
    public static string ConvertToBase64(this Stream stream)
        var bytes = new Byte[(int)stream.Length];

        stream.Seek(0, SeekOrigin.Begin);
        stream.Read(bytes, 0, (int)stream.Length);

        return Convert.ToBase64String(bytes);

The methods for Read (and also Write) and optimized for the respective class (whether is file stream, memory stream, etc.) and will do the work for you. For simple task like this, there is no need of readers, and etc.

The only drawback is that the stream is copied into byte array, but that is how the conversion to base64 via Convert.ToBase64String works unfortunately.

If Else in LINQ

you should change like this:

private string getValue(float price)
    if(price >0)
        return "debit";
    return "credit";

//Get value like this
select new {p.PriceID, Type = getValue(p.Price)};

How to print to the console in Android Studio?

Android has its own method of printing messages (called logs) to the console, known as the LogCat.

When you want to print something to the LogCat, you use a Log object, and specify the category of message.

The main options are:

  • DEBUG: Log.d
  • ERROR: Log.e
  • INFO: Log.i
  • VERBOSE: Log.v
  • WARN: Log.w

You print a message by using a Log statement in your code, like the following example:

Log.d("myTag", "This is my message");

Within Android Studio, you can search for log messages labelled myTag to easily find the message in the LogCat. You can also choose to filter logs by category, such as "Debug" or "Warn".

What is this CSS selector? [class*="span"]

.show-grid [class*="span"]

It's a CSS selector that selects all elements with the class show-grid that has a child element whose class contains the name span.

Why is Node.js single threaded?

Node.js was created explicitly as an experiment in async processing. The theory was that doing async processing on a single thread could provide more performance and scalability under typical web loads than the typical thread-based implementation.

And you know what? In my opinion that theory's been borne out. A node.js app that isn't doing CPU intensive stuff can run thousands more concurrent connections than Apache or IIS or other thread-based servers.

The single threaded, async nature does make things complicated. But do you honestly think it's more complicated than threading? One race condition can ruin your entire month! Or empty out your thread pool due to some setting somewhere and watch your response time slow to a crawl! Not to mention deadlocks, priority inversions, and all the other gyrations that go with multithreading.

In the end, I don't think it's universally better or worse; it's different, and sometimes it's better and sometimes it's not. Use the right tool for the job.

Remove empty space before cells in UITableView

Xcode 8 bug…

Try this first if your Storyboard UITableView style is set to Plain.

Set the table's style to Grouped and then back to Plain. This removed the space in my app at the head of my UITableView.

Javascript to sort contents of select element

Just another way to do it with jQuery:

// sorting;
var selectElm = $("select"),
    selectSorted = selectElm.find("option").toArray().sort(function (a, b) {
        return (a.innerHTML.toLowerCase() > b.innerHTML.toLowerCase()) ? 1 : -1;
$.each(selectSorted, function (key, value) {

updating nodejs on ubuntu 16.04

To update, you can install n

sudo npm install -g n

Then just :

sudo n latest

or a specific version

sudo n 8.9.0

How to exit in Node.js

import mongosse from 'mongoose'
import dotenv from 'dotenv'
import colors from 'colors'
import users from './data/users.js'
import products from './data/products.js'
import User from './models/userModel.js'
import Product from './models/productModel.js'
import Order from './models/orderModel.js'
import connectDB from './config/db.js'



const importData = async()=>{
    await Order.deleteMany()
    await Product.deleteMany()
    await User.deleteMany()

    const createdUsers = await User.insertMany(users)
    const adiminUser = createdUsers[0]._id

    sampleProducts = =>{
        return {...product, user:adiminUser }
    await Product.insertMany(sampleProducts)

    console.log('Data Imported!'.green.inverse)
    process.exit()      //success and exit

    process.exit(1)   //error and exit



so here im populating some collections in a db and in the try block if i dont get any errors then we exit it with a success message , so for that we use process.exit() with nothing in the parameter. If theres an error then we need to exit with an unsuccessfull message so we pass 1 in the parameter like this , process.exit(1).

extra: Here by exiting we mean exiting that typical node js program. eg if this code was in a file called dbOperations.js then the process.exit will exit and wont run any code that follows after process.exit

Is there a naming convention for MySQL?

Thankfully, PHP developers aren't "Camel case bigots" like some development communities I know.

Your conventions sound fine.

Just so long as they're a) simple, and b) consistent - I don't see any problems :)

PS: Personally, I think 5) is overkill...

How to update MySql timestamp column to current timestamp on PHP?

Another option:

UPDATE `table` SET the_col = current_timestamp

Looks odd, but works as expected. If I had to guess, I'd wager this is slightly faster than calling now().

How find out which process is using a file in Linux?

$ lsof | tree MyFold

As shown in the image attached:

enter image description here

Split pandas dataframe in two if it has more than 10 rows

Below is a simple function implementation which splits a DataFrame to chunks and a few code examples:

import pandas as pd

def split_dataframe_to_chunks(df, n):
    df_len = len(df)
    count = 0
    dfs = []

    while True:
        if count > df_len-1:

        start = count
        count += n
        #print("%s : %s" % (start, count))
        dfs.append(df.iloc[start : count])
    return dfs

# Create a DataFrame with 10 rows
df = pd.DataFrame([i for i in range(10)])

# Split the DataFrame to chunks of maximum size 2
split_df_to_chunks_of_2 = split_dataframe_to_chunks(df, 2)
print([len(i) for i in split_df_to_chunks_of_2])
# prints: [2, 2, 2, 2, 2]

# Split the DataFrame to chunks of maximum size 3
split_df_to_chunks_of_3 = split_dataframe_to_chunks(df, 3)
print([len(i) for i in split_df_to_chunks_of_3])
# prints [3, 3, 3, 1]

Do on-demand Mac OS X cloud services exist, comparable to Amazon's EC2 on-demand instances?

I have tried they are cheap and they have great bandwith so their is low latency. You need teamviewer to log into the virtual system though

How to allow only numbers in textbox in mvc4 razor

for decimal values greater than zero, HTML5 works as follows:

<input id="txtMyDecimal" min="0" step="any" type="number">

How to make Scrollable Table with fixed headers using CSS

I can think of a cheeky way to do it, I don't think this will be the best option but it will work.

Create the header as a separate table then place the other in a div and set a max size, then allow the scroll to come in by using overflow.

table {_x000D_
  width: 500px;_x000D_
.scroll {_x000D_
  max-height: 60px;_x000D_
  overflow: auto;_x000D_
<table border="1">_x000D_
<div class="scroll">_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>More Text</td><td>More Text</td><td>More Text</td><td>More Text</td></tr>_x000D_
    <tr><td>Text Text</td><td>Text Text</td><td>Text Text</td><td>Text Text</td></tr>_x000D_
    <tr><td>Even More Text Text</td><td>Even More Text Text</td><td>Even More Text Text</td><td>Even More Text Text</td></tr>_x000D_

What's the difference between disabled="disabled" and readonly="readonly" for HTML form input fields?

Same as the other answers (disabled isn't sent to the server, readonly is) but some browsers prevent highlighting of a disabled form, while read-only can still be highlighted (and copied).

A read-only field cannot be modified. However, a user can tab to it, highlight it, and copy the text from it.

How to sort List<Integer>?

You are using Lists, concrete ArrayList. ArrayList also implements Collection interface. Collection interface has sort method which is used to sort the elements present in the specified list of Collection in ascending order. This will be the quickest and possibly the best way for your case.

Sorting a list in ascending order can be performed as default operation on this way:


Sorting a list in descending order can be performed on this way:


According to these facts, your solution has to be written like this:

public class tes 
    public static void main(String args[])
        List<Integer> lList = new ArrayList<Integer>();

        for(int i=0; i<lList.size();i++ )

More about Collections you can read here.

How to recursively find and list the latest modified files in a directory with subdirectories and times

This is what I'm using (very efficient):

function find_last () { find "${1:-.}" -type f -printf '%TY-%Tm-%Td %TH:%TM %P\n' 2>/dev/null | sort | tail -n "${2:-10}"; }


  • it spawns only 3 processes


find_last [dir [number]]


  • dir - a directory to be searched [current dir]
  • number - number of newest files to display [10]

Output for find_last /etc 4 looks like this:

2019-07-09 12:12 cups/printers.conf
2019-07-09 14:20 salt/minion.d/_schedule.conf
2019-07-09 14:31 network/interfaces
2019-07-09 14:41 environment

Linux : Search for a Particular word in a List of files under a directory

also you can try the following.

find . -name '*.java' -exec grep "<yourword" /dev/null {} \;

It gets all the files with .java extension and searches 'yourword' in each file, if it presents, it lists the file.

Hope it helps :)

How to display scroll bar onto a html table

Not sure why no one mentioned to just use the built-in sticky header style for elements. Worked great for me.

.tableContainerDiv {
   overflow: auto;
   max-height: 80em;
th {
   position: sticky;
   top: 0;
   background: white;

Put a min-width on the in @media if you need to make responsive (or similar).

see Table headers position:sticky or Position Sticky and Table Headers

How to split string using delimiter char using T-SQL?

It is terrible, but you can try to use

SUBSTRING(Table1.Col1,0,PATINDEX('%|%=',Table1.Col1)) as myString

This code is probably not 100% right though. need to be adjusted

Detect iPhone/iPad purely by css

I use these:

/* Non-Retina */
@media screen and (-webkit-max-device-pixel-ratio: 1) {

/* Retina */
@media only screen and (-webkit-min-device-pixel-ratio: 1.5),
only screen and (-o-min-device-pixel-ratio: 3/2),
only screen and (min--moz-device-pixel-ratio: 1.5),
only screen and (min-device-pixel-ratio: 1.5) {

/* iPhone Portrait */
@media screen and (max-device-width: 480px) and (orientation:portrait) {

/* iPhone Landscape */
@media screen and (max-device-width: 480px) and (orientation:landscape) {

/* iPad Portrait */
@media screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:portrait) {

/* iPad Landscape */
@media screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:landscape) {

:first-child not working as expected

:first-child selects the first h1 if and only if it is the first child of its parent element. In your example, the ul is the first child of the div.

The name of the pseudo-class is somewhat misleading, but it's explained pretty clearly here in the spec.

jQuery's :first selector gives you what you're looking for. You can do this:

$('.detail_container h1:first').css("color", "blue");

sql try/catch rollback/commit - preventing erroneous commit after rollback

In your first example, you are correct. The batch will hit the commit transaction, regardless of whether the try block fires.

In your second example, I agree with other commenters. Using the success flag is unnecessary.

I consider the following approach to be, essentially, a light weight best practice approach.

If you want to see how it handles an exception, change the value on the second insert from 255 to 256.



    INSERT  INTO #TEMP( ID ) VALUES  ( 255 )

        @ErrorMessage NVARCHAR(4000),
        @ErrorSeverity INT,
        @ErrorState INT;
        @ErrorMessage = ERROR_MESSAGE(),
        @ErrorSeverity = ERROR_SEVERITY(),
        @ErrorState = ERROR_STATE();




How to display and hide a div with CSS?

Html Code :

    <a id="f">Show First content!</a>
    <a id="s">Show Second content!!</a>
    <div class="a">Default Content</div>
    <div class="ab hideDiv">First content</div>
    <div class="abc hideDiv">Second content</div>

Script code:

$(document).ready(function() {
    }).mouseout(function() {

    }).mouseout(function() {

css code:


Couldn't process file resx due to its being in the Internet or Restricted zone or having the mark of the web on the file

  1. Find the path from error log and open the file in explorer 2)select the file and right-click -> properties
  2. Then check the 'unblock' option and click on apply enter image description here

How do I keep the screen on in my App?

No need to add permission and do tricks. Just use below text in your main layout.


How to find the width of a div using vanilla JavaScript?

You can use clientWidth or offsetWidth Mozilla developer network reference

It would be like:

document.getElementById("yourDiv").clientWidth; // returns number, like 728

or with borders width :

document.getElementById("yourDiv").offsetWidth; // 728 + borders width

How to change line color in EditText

Try the following way, it will convert the bottom line color of EditText, when used as a background property.

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="">
            <solid android:color="@android:color/transparent" />
                android:color="@android:color/black" />

User GETDATE() to put current date into SQL variable

Just use GetDate() not Select GetDate()

DECLARE @LastChangeDate as date 
SET @LastChangeDate = GETDATE() 

but if it's SQL Server, you can also initialize in same step as declaration...

DECLARE @LastChangeDate date = getDate()

How can I deserialize JSON to a simple Dictionary<string,string> in ASP.NET?

I hope this answer is not considered too off-topic, but I had a similar issue where I was looking for a tool to parse only parts of a nested JSON which is not that straightforward with the accepted solutions.

If you have a similar issue, it might be worth to check out JTokken as described in this original post or in my answer to a similar question.

Difference between @Mock and @InjectMocks

This is a sample code on how @Mock and @InjectMocks works.

Say we have Game and Player class.

class Game {

    private Player player;

    public Game(Player player) {
        this.player = player;

    public String attack() {
        return "Player attack with: " + player.getWeapon();


class Player {

    private String weapon;

    public Player(String weapon) {
        this.weapon = weapon;

    String getWeapon() {
        return weapon;

As you see, Game class need Player to perform an attack.

class GameTest {

    Player player;

    Game game;

    public void attackWithSwordTest() throws Exception {

        assertEquals("Player attack with: Sword", game.attack());


Mockito will mock a Player class and it's behaviour using when and thenReturn method. Lastly, using @InjectMocks Mockito will put that Player into Game.

Notice that you don't even have to create a new Game object. Mockito will inject it for you.

// you don't have to do this
Game game = new Game(player);

We will also get same behaviour using @Spy annotation. Even if the attribute name is different.

public class GameTest {

  @Mock Player player;

  @Spy List<String> enemies = new ArrayList<>();

  @InjectMocks Game game;

  @Test public void attackWithSwordTest() throws Exception {


    assertEquals(2, game.numberOfEnemies());

    assertEquals("Player attack with: Sword", game.attack());

class Game {

  private Player player;

  private List<String> opponents;

  public Game(Player player, List<String> opponents) {
    this.player = player;
    this.opponents = opponents;

  public int numberOfEnemies() {
    return opponents.size();

  // ...

That's because Mockito will check the Type Signature of Game class, which is Player and List<String>.

What is Type-safe?

Many answers here conflate type-safety with static-typing and dynamic-typing. A dynamically typed language (like smalltalk) can be type-safe as well.

A short answer: a language is considered type-safe if no operation leads to undefined behavior. Many consider the requirement of explicit type conversions necessary for a language to be strictly typed, as automatic conversions can sometimes leads to well defined but unexpected/unintuitive behaviors.

What is the difference between ManualResetEvent and AutoResetEvent in .NET?

Just imagine that the AutoResetEvent executes WaitOne() and Reset() as a single atomic operation.

VBA Runtime Error 1004 "Application-defined or Object-defined error" when Selecting Range

The same thing happened to me. In my case most of the worksheet was in protected mode (though the cells relevant to the macro were unlocked). When I disabled the protection on the worksheet, the macro worked seems VBA doesn't like locked cells even if they are not used by the macro.

Recyclerview inside ScrollView not scrolling smoothly

Replacing ScrollView with NestedScrollView resulted into smooth scrolling to the bottom.

Get position/offset of element relative to a parent container?

I got another Solution. Subtract parent property value from child property value

$('child-div').offset().top - $('parent-div').offset().top;

Display string as html in mvc view

You are close you want to use @Html.Raw(str)

@Html.Encode takes strings and ensures that all the special characters are handled properly. These include characters like spaces.

'dict' object has no attribute 'has_key'

has_key was removed in Python 3. From the documentation:

  • Removed dict.has_key() – use the in operator instead.

Here's an example:

if start not in graph:
    return None

What are native methods in Java and where should they be used?

Native methods allow you to use code from other languages such as C or C++ in your java code. You use them when java doesn't provide the functionality that you need. For example, if I were writing a program to calculate some equation and create a line graph of it, I would use java, because it is the language I am best in. However, I am also proficient in C. Say in part of my program I need to calculate a really complex equation. I would use a native method for this, because I know some C++ and I know that C++ is much faster than java, so if I wrote my method in C++ it would be quicker. Also, say I want to interact with another program or device. This would also use a native method, because C++ has something called pointers, which would let me do that.

Conversion of a datetime2 data type to a datetime data type results out-of-range value

I ran into this issue on a simple console app project and my quick solution is to convert any possible datetime2 dates to a nullable datetime by running this method:

static DateTime? ParseDateTime2(DateTime? date)
        if (date == null || date.ToString() == "1/1/0001 12:00:00 AM")
            return null;
            return date;

This is certainly not a completely comprehensive method, but it worked for my needs and maybe it'll help others!

Open File in Another Directory (Python)

import os
import os.path
import shutil

You find your current directory:

d = os.getcwd() #Gets the current working directory

Then you change one directory up:

os.chdir("..") #Go up one directory from working directory

Then you can get a tupple/list of all the directories, for one directory up:

o = [os.path.join(d,o) for o in os.listdir(d) if os.path.isdir(os.path.join(d,o))] # Gets all directories in the folder as a tuple

Then you can search the tuple for the directory you want and open the file in that directory:

for item in o:
    if os.path.exists(item + '\\testfile.txt'):
    file = item + '\\testfile.txt'

Then you can do stuf with the full file path 'file'

CSS /JS to prevent dragging of ghost image?

You can set the draggable attribute to false in either the markup or JavaScript code.

// As a jQuery method: $('#myImage').attr('draggable', false);_x000D_
document.getElementById('myImage').setAttribute('draggable', false);
<img id="myImage" src="">

Conversion failed when converting date and/or time from character string in SQL SERVER 2008


SET @FromDate =  'Jan 10 2016 12:00AM'

SET @ToDate = 'Jan 10 2017 12:00AM'

DECLARE @Dynamic_Qry nvarchar(Max) =''

SET @Dynamic_Qry='SELECT

     CASE WHEN (  ''IssueDate''   =''IssueDate'') THEN 
          WHEN (''IssueDate'' =''ExpiryDate'' ) THEN       
          CHEKDATE ), 101)  


AND  (
        CASE WHEN (  ''IssueDate''   =''IssueDate'') THEN
             WHEN (''IssueDate'' =''ExpiryDate'' ) THEN EMP_DOCUMENT.EXPIRY_DATE 
             CHEKDATE ), 101)  
) BETWEEN  '''+ CONVERT(CHAR(10), @FromDate, 126) +'''  AND '''+CONVERT(CHAR(10),  @ToDate , 126

print @Dynamic_Qry


C# Convert a Base64 -> byte[]

You're looking for the FromBase64Transform class, used with the CryptoStream class.

If you have a string, you can also call Convert.FromBase64String.

SQL Server 2012 can't start because of a login failure

One possibility is when installed sql server data tools Bi, while sql server was already set up.

Solution:- 1.Just Repair the sql server with the set up instance

if solution does not work , than its worth your time meddling with services.msc

Android activity life cycle - what are all these methods for?

Adding some more info on top of highly rated answer (Added additional section of KILLABLE and next set of methods, which are going to be called in the life cycle):


enter image description here

Note the "Killable" column in the above table -- for those methods that are marked as being killable, after that method returns the process hosting the activity may be killed by the system at any time without another line of its code being executed.

Because of this, you should use the onPause() method to write any persistent data (such as user edits) to storage. In addition, the method onSaveInstanceState(Bundle) is called before placing the activity in such a background state, allowing you to save away any dynamic instance state in your activity into the given Bundle, to be later received in onCreate(Bundle) if the activity needs to be re-created.

Note that it is important to save persistent data in onPause() instead of onSaveInstanceState(Bundle) because the latter is not part of the lifecycle callbacks, so will not be called in every situation as described in its documentation.

I would like to add few more methods. These are not listed as life cycle methods but they will be called during life cycle depending on some conditions. Depending on your requirement, you may have to implement these methods in your application for proper handling of state.

onPostCreate(Bundle savedInstanceState)

Called when activity start-up is complete (after onStart() and onRestoreInstanceState(Bundle) have been called).


Called when activity resume is complete (after onResume() has been called).

onSaveInstanceState(Bundle outState)

Called to retrieve per-instance state from an activity before being killed so that the state can be restored in onCreate(Bundle) or onRestoreInstanceState(Bundle) (the Bundle populated by this method will be passed to both).

onRestoreInstanceState(Bundle savedInstanceState)

This method is called after onStart() when the activity is being re-initialized from a previously saved state, given here in savedInstanceState.

My application code using all these methods:

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private EditText txtUserName;
    private EditText txtPassword;
    Button  loginButton;
    protected void onCreate(Bundle savedInstanceState) {
        Log.d("Ravi","Main OnCreate");
        txtUserName=(EditText) findViewById(;
        txtPassword=(EditText) findViewById(;
        loginButton =  (Button)  findViewById(;


    public void onClick(View view) {
        Log.d("Ravi", "Login processing initiated");
        Intent intent = new Intent(this,LoginActivity.class);
        Bundle bundle = new Bundle();
       // IntentFilter
    public void onActivityResult(int requestCode, int resultCode, Intent resIntent){
        Log.d("Ravi back result:", "start");
        String result = resIntent.getStringExtra("result");
        Log.d("Ravi back result:", result);
        TextView txtView = (TextView)findViewById(;

        Intent sendIntent = new Intent();
        sendIntent.putExtra(Intent.EXTRA_TEXT, "Message...");

    protected void onStart() {
        Log.d("Ravi","Main Start");

    protected void onRestart() {
        Log.d("Ravi","Main ReStart");

    protected void onPause() {
        Log.d("Ravi","Main Pause");

    protected void onResume() {
        Log.d("Ravi","Main Resume");

    protected void onStop() {
        Log.d("Ravi","Main Stop");

    protected void onDestroy() {
        Log.d("Ravi","Main OnDestroy");

    public void onPostCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
        super.onPostCreate(savedInstanceState, persistentState);
        Log.d("Ravi","Main onPostCreate");

    protected void onPostResume() {
        Log.d("Ravi","Main PostResume");

    public void onSaveInstanceState(Bundle outState, PersistableBundle outPersistentState) {
        super.onSaveInstanceState(outState, outPersistentState);

    protected void onRestoreInstanceState(Bundle savedInstanceState) {

Login Activity:

public class LoginActivity extends AppCompatActivity {

    private TextView txtView;
    protected void onCreate(Bundle savedInstanceState) {
        txtView = (TextView) findViewById(;
        Log.d("Ravi","Login OnCreate");
        Bundle bundle = getIntent().getExtras();
        //Intent  intent = new Intent(this,MainActivity.class);
        Intent  intent = new Intent();
       // finish();

output: ( Before pause)

D/Ravi: Main OnCreate
D/Ravi: Main Start
D/Ravi: Main Resume
D/Ravi: Main PostResume

output: ( After resume from pause)

D/Ravi: Main ReStart
D/Ravi: Main Start
D/Ravi: Main Resume
D/Ravi: Main PostResume

Note that onPostResume() is invoked even though it's not quoted as life cycle method.

How to prevent line-break in a column of a table cell (not a single cell)?

Use the nowrap style:

<td style="white-space:nowrap;">...</td>

It's CSS!

Android load from URL to Bitmap

public static Bitmap getBitmapFromURL(String src) {
    try {
        URL url = new URL(src);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        InputStream input = connection.getInputStream();
        Bitmap myBitmap = BitmapFactory.decodeStream(input);
        return myBitmap;
    } catch (IOException e) {
        // Log exception
        return null;

postgresql - sql - count of `true` values

select f1,
       CASE WHEN f1 = 't' THEN COUNT(*) 
            WHEN f1 = 'f' THEN COUNT(*) 
            END AS counts,
       (SELECT COUNT(*) FROM mytable) AS total_counts
from mytable
group by f1

Or Maybe this

       SUM(CASE WHEN f1 = 'f' THEN 1 END) AS f,
       SUM(CASE WHEN f1 NOT IN ('t','f') OR f1 IS NULL THEN 1 END) AS others,
       SUM(CASE WHEN f1 IS NOT NULL OR f1 IS NULL THEN 1 ELSE 0 END) AS total_count
FROM mytable;

How to delete multiple rows in SQL where id = (x to y)

You can use BETWEEN:

where id between 163 and 265

How to escape JSON string?

I ran speed tests on some of these answers for a long string and a short string. Clive Paterson's code won by a good bit, presumably because the others are taking into account serialization options. Here are my results:

Apple Banana
System.Web.HttpUtility.JavaScriptStringEncode: 140ms
System.Web.Helpers.Json.Encode: 326ms
Newtonsoft.Json.JsonConvert.ToString: 230ms
Clive Paterson: 108ms

System.Web.HttpUtility.JavaScriptStringEncode: 2849ms
System.Web.Helpers.Json.Encode: 3300ms
Newtonsoft.Json.JsonConvert.ToString: 2827ms
Clive Paterson: 1173ms

And here is the test code:

public static void Main(string[] args)
    var testStr1 = "Apple Banana";
    var testStr2 = @"\\some\long\path\with\lots\of\things\to\escape\some\long\path\t\with\lots\of\n\things\to\escape\some\long\path\with\lots\of\""things\to\escape\some\long\path\with\lots""\of\things\to\escape";

    foreach (var testStr in new[] { testStr1, testStr2 })
        var results = new Dictionary<string,List<long>>();

        for (var n = 0; n < 10; n++)
            var count = 1000 * 1000;

            var sw = Stopwatch.StartNew();
            for (var i = 0; i < count; i++)
                var s = System.Web.HttpUtility.JavaScriptStringEncode(testStr);
            var t = sw.ElapsedMilliseconds;

            sw = Stopwatch.StartNew();
            for (var i = 0; i < count; i++)
                var s = System.Web.Helpers.Json.Encode(testStr);
            t = sw.ElapsedMilliseconds;

            sw = Stopwatch.StartNew();
            for (var i = 0; i < count; i++)
                var s = Newtonsoft.Json.JsonConvert.ToString(testStr);
            t = sw.ElapsedMilliseconds;

            sw = Stopwatch.StartNew();
            for (var i = 0; i < count; i++)
                var s = cleanForJSON(testStr);
            t = sw.ElapsedMilliseconds;
            results.GetOrCreate("Clive Paterson").Add(t);

        foreach (var result in results)
            Console.WriteLine(result.Key + ": " + Math.Round(result.Value.Skip(1).Average()) + "ms");


Ignore fields from Java object dynamically while sending as JSON from Spring MVC

I know I'm a bit late to the party, but I actually ran into this as well a few months back. All of the available solutions weren't very appealing to me (mixins? ugh!), so I ended up creating a new library to make this process cleaner. It's available here if anyone would like to try it out:

The basic usage is pretty simple, you use the JsonView object in your controller methods like so:

import com.monitorjbl.json.JsonView;
import static com.monitorjbl.json.Match.match;

@RequestMapping(method = RequestMethod.GET, value = "/myObject")
public void getMyObjects() {
    //get a list of the objects
    List<MyObject> list = myObjectService.list();

    //exclude expensive field
    JsonView.with(list).onClass(MyObject.class, match().exclude("contains"));

You can also use it outside of Spring:

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import static com.monitorjbl.json.Match.match;

ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addSerializer(JsonView.class, new JsonViewSerializer());

      .onClass(MyObject.class, match()
      .onClass(MySmallObject.class, match()

Load different application.yml in SpringBoot Test

One option is to work with profiles. Create a file called application-test.yml, move all properties you need for those tests to that file and then add the @ActiveProfiles annotation to your test class:

@SpringApplicationConfiguration(classes = Application.class)
@ActiveProfiles("test") // Like this
public class MyIntTest{

Be aware, it will additionally load the application-test.yml, so all properties that are in application.yml are still going to be applied as well. If you don't want that, either use a profile for those as well, or override them in your application-test.yml.

Calling a Fragment method from a parent Activity


Excel VBA: AutoFill Multiple Cells with Formulas

Based on my Comment here is one way to get what you want done:

Start byt selecting any cell in your range and Press Ctrl + T

This will give you this pop up:

enter image description here

make sure the Where is your table text is correct and click ok you will now have:

enter image description here

Now If you add a column header in D it will automatically be added to the table all the way to the last row:

enter image description here

Now If you enter a formula into this column:

enter image description here

After you enter it, the formula will be auto filled all the way to last row:

enter image description here

Now if you add a new row at the next row under your table:

enter image description here

Once entered it will be resized to the width of your table and all columns with formulas will be added also:

enter image description here

Hope this solves your problem!

How to improve Netbeans performance?

Is it a corporate Windows machine? If so aggressive virus scanners can really slow down modern IDEs. Check your task manager for processes that are using a lot of CPU or disk reads.

Make body have 100% of the browser height

If you want to keep the margins on the body and don't want scroll bars, use the following css:

html { height:100%; }
body { position:absolute; top:0; bottom:0; right:0; left:0; }

Setting body {min-height:100%} will give you scroll bars.

See demo at,output .

SecurityError: Blocked a frame with origin from accessing a cross-origin frame

Check the domain's web server for http://www.<domain>.com configuration for X-Frame-Options It is a security feature designed to prevent clickJacking attacks,

How Does clickJacking work?

  1. The evil page looks exactly like the victim page.
  2. Then it tricked users to enter their username and password.

Technically the evil has an iframe with the source to the victim page.

    <iframe src=''/>
    <input id="username" type="text" style="display: none;"/>
    <input id="password" type="text" style="display: none;"/>
        //some JS code that click jacking the user username and input from inside the iframe...

How the security feature work

If you want to prevent web server request to be rendered within an iframe add the x-frame-options

X-Frame-Options DENY

The options are:

  1. SAMEORIGIN //allow only to my own domain render my HTML inside an iframe.
  2. DENY //do not allow my HTML to be rendered inside any iframe
  3. "ALLOW-FROM" //allow specific domain to render my HTML inside an iframe

This is IIS config example:

           <add name="X-Frame-Options" value="SAMEORIGIN" />

The solution to the question

If the web server activated the security feature it may cause a client-side SecurityError as it should.

No connection could be made because the target machine actively refused it

Make Sure all services used by your application are on, which are using host and port to utilize them . For e.g, as in my case, This error can come, If your application is utilizing a Redis server and it is not being able to connect to it on given port and host, thus producing this error .

Java FileWriter how to write to next Line

You can call the method newLine() provided by java, to insert the new line in to a file.

For more refernce -

AngularJS $http-post - convert binary to excel file and download

I created a service that will do this for you.

Pass in a standard $http object, and add some extra parameters.

1) A "type" parameter. Specifying the type of file you're retrieving. Defaults to: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
2) A "fileName" parameter. This is required, and should include the extension.


  method : 'POST',
  url : '--- enter the url that returns a file here ---',
  data : ifYouHaveDataEnterItHere,
  type : 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet', // this is the default
  fileName : 'YourFileName.xlsx'
}).then(res => {}).catch(e => {});

That's all you need. The file will be downloaded to the user's device without a popup.

Here's the git repo:

How to multiply individual elements of a list with a number?

In NumPy it is quite simple

import numpy as np
S=[22, 33, 45.6, 21.6, 51.8]
SP = P*np.array(S)

I recommend taking a look at the NumPy tutorial for an explanation of the full capabilities of NumPy's arrays:

How to select unique records by SQL

just use inner join because group by won't work with multiple columns saying not contained in either an aggregate function.

FROM yourtable a
  (SELECT yourcolumn,
    MIN(id) as id
  FROM yourtable 
  GROUP BY yourcolumn
) AS b
  ON a.yourcolumn= b.yourcolumn
  AND =;

How to make Java honor the DNS Caching Timeout?

To summarize the other answers, in <jre-path>/lib/security/ you can set the value of the property networkaddress.cache.ttl to adjust how DNS lookups are cached. Note that this is not a system property but a security property. I was able to set this using:"networkaddress.cache.ttl", "<value>");

This can also be set by the system property though this will not override a security property if it is set elsewhere.

I would also like to add that if you are seeing this issue with web services in WebSphere, as I was, setting networkaddress.cache.ttl will not be enough. You need to set the system property disableWSAddressCaching to true. Unlike the time-to-live property, this can be set as a JVM argument or via System.setProperty).

IBM has a pretty detailed post on how WebSphere handles DNS caching here. The relevant piece to the above is:

To disable address caching for Web services, you need to set an additional JVM custom property disableWSAddressCaching to true. Use this property to disable address caching for Web services. If your system typically runs with lots of client threads, and you encounter lock contention on the wsAddrCache cache, you can set this custom property to true, to prevent caching of the Web services data.

Moving from JDK 1.7 to JDK 1.8 on Ubuntu

Just use these command lines:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer

If needed, you can also follow this Ubuntu tutorial.

Running code after Spring Boot starts

With spring configuration :

public class ProjectConfiguration {
    private static final Logger log = 

   public void doSomethingAfterStartup() {"hello world, I have just started up");

Java ResultSet how to check if there are any results

According to the most viable answer the suggestion is to use "isBeforeFirst()". That's not the best solution if you don't have a "forward only type".

There's a method called ".first()". It's less overkill to get the exact same result. You check whether there is something in your "resultset" and don't advance your cursor.

The documentation states: "(...) false if there are no rows in the result set".

    //do stuff      

You can also just call isBeforeFirst() to test if there are any rows returned without advancing the cursor, then proceed normally. – SnakeDoc Sep 2 '14 at 19:00

However, there's a difference between "isBeforeFirst()" and "first()". First generates an exception if done on a resultset from type "forward only".

Compare the two throw sections:

Okay, basically this means that you should use "isBeforeFirst" as long as you have a "forward only" type. Otherwise it's less overkill to use "first()".

How do I get time of a Python program's execution?

Use line_profiler.

line_profiler will profile the time individual lines of code take to execute. The profiler is implemented in C via Cython in order to reduce the overhead of profiling.

from line_profiler import LineProfiler
import random

def do_stuff(numbers):
    s = sum(numbers)
    l = [numbers[i]/43 for i in range(len(numbers))]
    m = ['hello'+str(numbers[i]) for i in range(len(numbers))]

numbers = [random.randint(1,100) for i in range(1000)]
lp = LineProfiler()
lp_wrapper = lp(do_stuff)

The results will be:

Timer unit: 1e-06 s

Total time: 0.000649 s
File: <ipython-input-2-2e060b054fea>
Function: do_stuff at line 4

Line #      Hits         Time  Per Hit   % Time  Line Contents
     4                                           def do_stuff(numbers):
     5         1           10     10.0      1.5      s = sum(numbers)
     6         1          186    186.0     28.7      l = [numbers[i]/43 for i in range(len(numbers))]
     7         1          453    453.0     69.8      m = ['hello'+str(numbers[i]) for i in range(len(numbers))]

How to increment a datetime by one day?

You can also import timedelta so the code is cleaner.

from datetime import datetime, timedelta
date = + timedelta(seconds=[delta_value])

Then convert to date to string

date = date.strftime('%Y-%m-%d %H:%M:%S')

Python one liner is

date = ( + timedelta(seconds=[delta_value])).strftime('%Y-%m-%d %H:%M:%S')

How to run html file on localhost?

  • Install Node js -

  • go to folder where you have html file:

    • In CMD, run the command to install http server- npm install http-server -g
    • To load file in the browser run - http-server
  • If you have specific html file. Run following command in CMD.- http-server fileName

  • by default port is 8080

  • Go to your browser and type localhost:8080. Your Application should run there.

  • If you want to run on different port: http-server fileName -p 9000

Note : To run your .js file run: node fileName.js

How to Configure SSL for Amazon S3 bucket

You can access your files via SSL like this:

If you use a custom domain for your bucket, you can use S3 and CloudFront together with your own SSL certificate (or generate a free one via Amazon Certificate Manager):

What is the Python equivalent of Matlab's tic and toc functions?

I changed @Eli Bendersky's answer a little bit to use the ctor __init__() and dtor __del__() to do the timing, so that it can be used more conveniently without indenting the original code:

class Timer(object):
    def __init__(self, name=None): = name
        self.tstart = time.time()

    def __del__(self):
            print '%s elapsed: %.2fs' % (, time.time() - self.tstart)
            print 'Elapsed: %.2fs' % (time.time() - self.tstart)

To use, simple put Timer("blahblah") at the beginning of some local scope. Elapsed time will be printed at the end of the scope:

for i in xrange(5):
    timer = Timer("eigh()")
    x = numpy.random.random((4000,4000));
    x = (x+x.T)/2
    print i+1
timer = None

It prints out:

eigh() elapsed: 10.13s
eigh() elapsed: 9.74s
eigh() elapsed: 10.70s
eigh() elapsed: 10.25s
eigh() elapsed: 11.28s

How to pass parameters to a Script tag?

JQuery has a way to pass parameters from HTML to javascript:

Put this in the myhtml.html file:

<!-- Import javascript -->
<script src="//"></script>
<!-- Invoke a different javascript file called subscript.js -->
<script id="myscript" src="subscript.js" video_filename="foobar.mp4">/script>

In the same directory make a subscript.js file and put this in there:

//Use jquery to look up the tag with the id of 'myscript' above.  Get 
//the attribute called video_filename, stuff it into variable filename.
var filename = $('#myscript').attr("video_filename");

//print filename out to screen.

Analyze Result:

Loading the myhtml.html page has 'foobar.mp4' print to screen. The variable called video_filename was passed from html to javascript. Javascript printed it to screen, and it appeared as embedded into the html in the parent.

jsfiddle proof that the above works:

MySQL: Check if the user exists and drop it

In case you have a school server where the pupils worked a lot. You can just clean up the mess by:

delete from user where User != 'root' and User != 'admin';
delete from db where User != 'root' and User != 'admin';

delete from tables_priv;
delete from columns_priv;

flush privileges;

Disable Laravel's Eloquent timestamps

If you only need to only to disable updating updated_at just add this method to your model.

public function setUpdatedAtAttribute($value)
    // to Disable updated_at

This will override the parent setUpdatedAtAttribute() method. created_at will work as usual. Same way you can write a method to disable updating created_at only.

How to add image in a TextView text?

I tried many different solutions and this for me was the best:

SpannableStringBuilder ssb = new SpannableStringBuilder(" Hello world!");
ssb.setSpan(new ImageSpan(context, R.drawable.image), 0, 1, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
tv_text.setText(ssb, TextView.BufferType.SPANNABLE);

This code uses a minimum of memory.

Calculating distance between two points (Latitude, Longitude)

In addition to the previous answers, here is a way to calculate the distance inside a SELECT:

    @La1 float , @Lo1 float , @La2 float, @Lo2 float
    -- Distance in Meters
    SELECT GEOGRAPHY::Point(@La1, @Lo1, 4326).STDistance(GEOGRAPHY::Point(@La2, @Lo2, 4326))
    AS Distance


select Distance
from Place P1,
     Place P2,
outer apply dbo.Get_Distance(P1.latitude, P1.longitude, P2.latitude, P2.longitude)

Scalar functions also work but they are very inefficient when computing large amount of data.

I hope this might help someone.

To show only file name without the entire directory path

Use the basename command:

basename /home/user/new/*.txt

How do you add an ActionListener onto a JButton in Java

I'm didn't totally follow, but to add an action listener, you just call addActionListener (from Abstract Button). If this doesn't totally answer your question, can you provide some more details?

Exception in thread "main" java.lang.Error: Unresolved compilation problems

Your problem is in this line: Message messageObject = new Message ();
This error says that the Message class is not known at compile time.

So you need to import the Message class.

Something like this:

import package1.package2.Message;

Check this out.

how to send multiple data with $.ajax() jquery

var data = 'id='+ id  & 'name='+ name;

The ampersand needs to be quoted as well:

var data = 'id='+ id  + '&name='+ name;

Transparent scrollbar with css

Try this one, it works fine for me.


    width: 0px;
    background-color: transparent;
    -webkit-border-radius: 6px;

and here is the working demo:

How to normalize a histogram in MATLAB?

The area of abcd`s PDF is not one, which is impossible like pointed out in many comments. Assumptions done in many answers here

  1. Assume constant distance between consecutive edges.
  2. Probability under pdf should be 1. The normalization should be done as Normalization with probability, not as Normalization with pdf, in histogram() and hist().

Fig. 1 Output of hist() approach, Fig. 2 Output of histogram() approach

enter image description here enter image description here

The max amplitude differs between two approaches which proposes that there are some mistake in hist()'s approach because histogram()'s approach uses the standard normalization. I assume the mistake with hist()'s approach here is about the normalization as partially pdf, not completely as probability.

Code with hist() [deprecated]

Some remarks

  1. First check: sum(f)/N gives 1 if Nbins manually set.
  2. pdf requires the width of the bin (dx) in the graph g


[f,x]=hist(randn(N,1),Nbins); % create histogram from ND

%METHOD 4: Count Densities, not Sums!
dx=diff(x(1:2)); % width of bin
g=1/sqrt(2*pi)*exp(-0.5*x.^2) .* dx; % pdf of ND with dx
% 1.0000
bar(x, f/sum(f));hold on
plot(x,g,'r');hold off

Output is in Fig. 1.

Code with histogram()

Some remarks

  1. First check: a) sum(f) is 1 if Nbins adjusted with histogram()'s Normalization as probability, b) sum(f)/N is 1 if Nbins is manually set without normalization.
  2. pdf requires the width of the bin (dx) in the graph g


%%METHOD 5: with histogram()

h = histogram(randn(N,1), 'Normalization', 'probability') % hist() deprecated!
for counter=1:Nbins
    midPointShift=abs(edges(counter)-edges(counter+1))/2; % same constant for all
dx=diff(x(1:2)); % constast for all
g=1/sqrt(2*pi)*exp(-0.5*x.^2) .* dx; % pdf of ND
% Use if Nbins manually set
%new_area=sum(f)/N % diff of consecutive edges constant
% Use if histogarm() Normalization probability
% 1.0000
% No bar() needed here with histogram() Normalization probability
hold on;
plot(x,g,'r');hold off

Output in Fig. 2 and expected output is met: area 1.0000.

Matlab: 2016a
System: Linux Ubuntu 16.04 64 bit
Linux kernel 4.6

How to parse XML to R data frame

Here's a partial solution using xml2. Breaking the solution up into smaller pieces generally makes it easier to ensure everything is lined up:

data <- read_xml("")

# Point locations
point <- data %>% xml_find_all("//point")
point %>% xml_attr("latitude") %>% as.numeric()
point %>% xml_attr("longitude") %>% as.numeric()

# Start time
data %>% 
  xml_find_all("//start-valid-time") %>% 

# Temperature
data %>% 
  xml_find_all("//temperature[@type='hourly']/value") %>% 
  xml_text() %>% 

How to sort dates from Oldest to Newest in Excel?

After some frustration I tried the following which worked for me:

Convert cells to date format if not already done. Go to the Data tab and click sort. Click sort after choosing expand selection or continue with current selection. Sort by Date Sort on Values order Z to A for newest date first. Click OK. Choose "Sort anything that looks like a number, as a number".


PHP Convert String into Float/Double

If the function floatval does not work you can try to make this :

    $string = "2968789218";
    $float = $string * 1.0;
    echo $float;

But for me all the previous answer worked ( try it in ) Maybe the problem is on your server ?

Qt - reading from a text file

You have to replace string line

QString line = in.readLine();

into while:

QFile file("/home/hamad/lesson11.txt");
if(! {
    QMessageBox::information(0, "error", file.errorString());

QTextStream in(&file);

while(!in.atEnd()) {
    QString line = in.readLine();    
    QStringList fields = line.split(",");    


Dump all tables in CSV format using 'mysqldump'

This worked well for me:

mysqldump <DBNAME> --fields-terminated-by ',' \
--fields-enclosed-by '"' --fields-escaped-by '\' \
--no-create-info --tab /var/lib/mysql-files/

Or if you want to only dump a specific table:

mysqldump <DBNAME> <TABLENAME> --fields-terminated-by ',' \
--fields-enclosed-by '"' --fields-escaped-by '\' \
--no-create-info --tab /var/lib/mysql-files/

I'm dumping to /var/lib/mysql-files/ to avoid this error:

mysqldump: Got error: 1290: The MySQL server is running with the --secure-file-priv option so it cannot execute this statement when executing 'SELECT INTO OUTFILE'

How to use npm with node.exe?

I just installed latest version of node (0.6.12) in Windows 7 using msi (node-v0.6.12.msi).

npm is already shipped with it, no need to include it separately.

I was facing permission issue while running npm (npm install mysql), from the path where my nodejs resided, i.e. C:\Program Files (x86)\nodejs

Then I followed below steps:

1) Added C:\Program Files (x86)\nodejs\npm in environment variables - Path system variable.

2) went back to only C:\ in command prompt and gave the command - npm install mysql - and voila! it worked..

Hope this helps.

A reference to the dll could not be added

My answer is a bit late, but as a quick test, make sure you are using the latest version of libraries.

In my case after updating a nuget library that was referencing another library causing the problem the problem disappeared.

Can't find keyplane that supports type 4 for keyboard iPhone-Portrait-NumberPad; using 3876877096_Portrait_iPhone-Simple-Pad_Default

Run the app using the simulator

iOS Simulator-> Hardware-> Keyboard -> iOS uses same layout as OS X

This will fix the issue if anyone out there is running their app on their device

Pointer to incomplete class type is not allowed

You get this error when declaring a forward reference inside the wrong namespace thus declaring a new type without defining it. For example:

namespace X
  namespace Y
    class A;

    void func(A* a) { ... } // incomplete type here!

...but, in class A was defined like this:

namespace X
  class A { ... };

Thus, A was defined as X::A, but I was using it as X::Y::A.

The fix obviously is to move the forward reference to its proper place like so:

namespace X
  class A;
  namespace Y
    void func(X::A* a) { ... } // Now accurately referencing the class`enter code here`

MSSQL Select statement with incremental integer column... not from a table

For SQL 2005 and up

SELECT ROW_NUMBER() OVER( ORDER BY SomeColumn ) AS 'rownumber',*
    FROM YourTable

for 2000 you need to do something like this

INTO #Ranks FROM YourTable WHERE 1=0

SELECT SomeColumn  FROM YourTable
ORDER BY SomeColumn 

Order By Ranks

see also here Row Number

Changing precision of numeric column in Oracle

By setting the scale, you decrease the precision. Try NUMBER(16,2).

Non-alphanumeric list order from os.listdir()

ls by default previews the files sorted by name. (ls options can be used to sort by date, size, ...)

files = list(os.popen("ls"))
files = [file.strip("\n") for file in files]

Using ls would have much better performance when the directory contains so many files.

Eclipse Build Path Nesting Errors

Got similar issue. Did following steps, issue resolved:

  1. Remove project in eclipse.
  2. Delete .Project file and . Settings folder.
  3. Import project as existing maven project again to eclipse.

How do I UPDATE from a SELECT in SQL Server?

In SQL Server 2008 (or better), use MERGE

   USING other_table S 
      ON =
         AND S.tsql = 'cool'
      SET col1 = S.col1, 
          col2 = S.col2;


   USING (
          SELECT id, col1, col2 
            FROM other_table 
           WHERE tsql = 'cool'
         ) S
      ON =
      SET col1 = S.col1, 
          col2 = S.col2;

How to convert flat raw disk image to vmdk for virtualbox or vmplayer?

Just to give you an another option, you could use as well. dd2vmdk is a *nix-based program that allows you to mount raw disk images (created by dd, dcfldd, dc3dd, ftk imager, etc) by taking the raw image, analyzing the master boot record (physical sector 0), and getting specific information that is need to create a vmdk file.

Personally, imo Qemu and the Zapotek's raw2vmdk tools are the best overall options to convert dd to vmdks.

Disclosure: I am the author of this project.

java.lang.ClassNotFoundException: com.fasterxml.jackson.annotation.JsonInclude$Value

I had the same error message. In my case, Jackson consisted of multiple JAR files. Sadly, they had different versions of jackson-core and jackson-annotations which resulted in the above exception.

Maybe you don't have the jackson-annotation JAR in your classpath, at least not in the correct version. You can analyze the used library versions with the command mvn dependency:tree.

Have Excel formulas that return 0, make the result blank

=IF(INDEX(a,b,c)="0","", INDEX(a,b,c)) worked for me with a minor modification. Excluding the 0 and no spaces in between quotations: =IF(INDEX(a,b,c)="","", INDEX(a,b,c))

NHibernate.MappingException: No persister for: XYZ

Sounds like you forgot to add a mapping assembly to the session factory configuration..

If you're using app.config...

    <property name="show_sql">true</property>
    <property name="query.substitutions">true 1, false 0, yes 'Y', no 'N'</property>
    <mapping assembly="Project.DomainModel"/>  <!-- Here -->

Google MAP API Uncaught TypeError: Cannot read property 'offsetWidth' of null

I had single quotes in my

var map = new google.maps.Map( document.getElementById('map_canvas') );

and replaced them with double quotes

var map = new google.maps.Map( document.getElementById("map_canvas") );

This did the trick for me.

How to get height of Keyboard?

Swift 3.0 and Swift 4.1

1- Register the notification in the viewWillAppear method:

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)

2- Method to be called:

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight = keyboardSize.height

How to declare a structure in a header that is to be used by multiple files in c?

if this structure is to be used by some other file func.c how to do it?

When a type is used in a file (i.e. func.c file), it must be visible. The very worst way to do it is copy paste it in each source file needed it.

The right way is putting it in an header file, and include this header file whenever needed.

shall we open a new header file and declare the structure there and include that header in the func.c?

This is the solution I like more, because it makes the code highly modular. I would code your struct as:


struct a
    int i;
    struct b
        int j;


I would put functions using this structure in the same header (the function that are "semantically" part of its "interface").

And usually, I could name the file after the structure name, and use that name again to choose the header guards defines.

If you need to declare a function using a pointer to the struct, you won't need the full struct definition. A simple forward declaration like:

struct a ;

Will be enough, and it decreases coupling.

or can we define the total structure in header file and include that in both source.c and func.c?

This is another way, easier somewhat, but less modular: Some code needing only your structure to work would still have to include all types.

In C++, this could lead to interesting complication, but this is out of topic (no C++ tag), so I won't elaborate.

then how to declare that structure as extern in both the files. ?

I fail to see the point, perhaps, but Greg Hewgill has a very good answer in his post How to declare a structure in a header that is to be used by multiple files in c?.

shall we typedef it then how?

  • If you are using C++, don't.
  • If you are using C, you should.

The reason being that C struct managing can be a pain: You have to declare the struct keyword everywhere it is used:

struct MyStruct ; /* Forward declaration */

struct MyStruct
   /* etc. */
} ;

void doSomething(struct MyStruct * p) /* parameter */
   struct MyStruct a ; /* variable */
   /* etc */

While a typedef will enable you to write it without the struct keyword.

struct MyStructTag ; /* Forward declaration */

typedef struct MyStructTag
   /* etc. */
} MyStruct ;

void doSomething(MyStruct * p) /* parameter */
   MyStruct a ; /* variable */
   /* etc */

It is important you still keep a name for the struct. Writing:

typedef struct
   /* etc. */
} MyStruct ;

will just create an anonymous struct with a typedef-ed name, and you won't be able to forward-declare it. So keep to the following format:

typedef struct MyStructTag
   /* etc. */
} MyStruct ;

Thus, you'll be able to use MyStruct everywhere you want to avoid adding the struct keyword, and still use MyStructTag when a typedef won't work (i.e. forward declaration)


Corrected wrong assumption about C99 struct declaration, as rightfully remarked by Jonathan Leffler.

Edit 2018-06-01:

Craig Barnes reminds us in his comment that you don't need to keep separate names for the struct "tag" name and its "typedef" name, like I did above for the sake of clarity.

Indeed, the code above could well be written as:

typedef struct MyStruct
   /* etc. */
} MyStruct ;

IIRC, this is actually what C++ does with its simpler struct declaration, behind the scenes, to keep it compatible with C:

// C++ explicit declaration by the user
struct MyStruct
   /* etc. */
} ;
// C++ standard then implicitly adds the following line
typedef MyStruct MyStruct;

Back to C, I've seen both usages (separate names and same names), and none has drawbacks I know of, so using the same name makes reading simpler if you don't use C separate "namespaces" for structs and other symbols.

How to find an object in an ArrayList by property

In Java8 you can use streams:

public static Carnet findByCodeIsIn(Collection<Carnet> listCarnet, String codeIsIn) {
    return -> codeIsIn.equals(carnet.getCodeIsin())).findFirst().orElse(null);

Additionally, in case you have many different objects (not only Carnet) or you want to find it by different properties (not only by cideIsin), you could build an utility class, to ecapsulate this logic in it:

public final class FindUtils {
    public static <T> T findByProperty(Collection<T> col, Predicate<T> filter) {

public final class CarnetUtils {
    public static Carnet findByCodeTitre(Collection<Carnet> listCarnet, String codeTitre) {
        return FindUtils.findByProperty(listCarnet, carnet -> codeTitre.equals(carnet.getCodeTitre()));

    public static Carnet findByNomTitre(Collection<Carnet> listCarnet, String nomTitre) {
        return FindUtils.findByProperty(listCarnet, carnet -> nomTitre.equals(carnet.getNomTitre()));

    public static Carnet findByCodeIsIn(Collection<Carnet> listCarnet, String codeIsin) {
        return FindUtils.findByProperty(listCarnet, carnet -> codeIsin.equals(carnet.getCodeIsin()));

LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++

Is this a console program project or a Windows project? I'm asking because for a Win32 and similar project, the entry point is WinMain().

  1. Right-click the Project (not the Solution) on the left side.
  2. Then click Properties -> Configuration Properties -> Linker -> System

If it says Subsystem Windows your entry point should be WinMain(), i.e.

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nShowCmd)
   your code here ...

Besides, speaking of the comments. This is a compile (or more precisely a Link) error, not a run-time error. When you start to debug, the compiler needs to make a complete program (not just to compile your module) and that is when the error occurs.

It does not even get to the point being loaded and run.

Diff files present in two different directories

In practice the question often arises together with some constraints. In that case following solution template may come in handy.

cd dir1
find . \( -name '*.txt' -o -iname '*.md' \) | xargs -i diff -u '{}' 'dir2/{}'

ImportError: No module named BeautifulSoup

I had the same problem with eclipse on windows 10.

I installed it like recommende over the windows command window (cmd) with:

C:\Users\NAMEOFUSER\AppData\Local\Programs\Python\beautifulsoup4-4.8.2\ install 

BeautifulSoup was install like this in my python directory:


After manually coping the bs4 and EGG-INFO folders into the site-packages folder everything started to work, also the example:

from bs4 import BeautifulSoup

html = """
            <p> Ich bin ein Absatz!</p>

soup = BeautifulSoup(html, 'html.parser')


Computational complexity of Fibonacci Sequence

There's a very nice discussion of this specific problem over at MIT. On page 5, they make the point that, if you assume that an addition takes one computational unit, the time required to compute Fib(N) is very closely related to the result of Fib(N).

As a result, you can skip directly to the very close approximation of the Fibonacci series:

Fib(N) = (1/sqrt(5)) * 1.618^(N+1) (approximately)

and say, therefore, that the worst case performance of the naive algorithm is

O((1/sqrt(5)) * 1.618^(N+1)) = O(1.618^(N+1))

PS: There is a discussion of the closed form expression of the Nth Fibonacci number over at Wikipedia if you'd like more information.

Django error - matching query does not exist

You can use this:

comment = Comment.objects.filter(pk=comment_id)

How to use the command update-alternatives --config java

There are many other binaries that need to be linked so I think it's much better to try something like sudo update-alternatives --all and choosing the right alternatives for everything else besides java and javac.

What to return if Spring MVC controller method doesn't return value?

you can return void, then you have to mark the method with @ResponseStatus(value = HttpStatus.OK) you don't need @ResponseBody

@RequestMapping(value = "/updateSomeData" method = RequestMethod.POST)
@ResponseStatus(value = HttpStatus.OK)
public void updateDataThatDoesntRequireClientToBeNotified(...) {

Only get methods return a 200 status code implicity, all others you have do one of three things:

  • Return void and mark the method with @ResponseStatus(value = HttpStatus.OK)
  • Return An object and mark it with @ResponseBody
  • Return an HttpEntity instance

How to get text in QlineEdit when QpushButton is pressed in a string?

The object name is not very important. what you should be focusing at is the variable that stores the lineedit object (le) and your pushbutton object(pb)

QObject(self.pb, SIGNAL("clicked()"), self.button_clicked)

def button_clicked(self):

I think this is what you want. I hope i got your question correctly :)

Can't access object property, even though it shows up in a console log

I just encountered this issue as well, and long story short my API was returning a string type and not JSON. So it looked exactly the same when you printed it to the log however whenever I tried to access the properties it gave me an undefined error.

API Code:

     var response = JsonConvert.DeserializeObject<StatusResult>(string Of object);
     return Json(response);

previously I was just returning:

return Json(string Of object);

Python 3: EOF when reading a line (Sublime Text 2 is angry)

It seems as of now, the only solution is still to install SublimeREPL.

To extend on Raghav's answer, it can be quite annoying to have to go into the Tools->SublimeREPL->Python->Run command every time you want to run a script with input, so I devised a quick key binding that may be handy:

To enable it, go to Preferences->Key Bindings - User, and copy this in there:

    {"keys":["ctrl+r"] , 
    "caption": "SublimeREPL: Python - RUN current file",
    "command": "run_existing_window_command", 
            "id": "repl_python_run",
            "file": "config/Python/Main.sublime-menu"

Naturally, you would just have to change the "keys" argument to change the shortcut to whatever you'd like.

Interesting 'takes exactly 1 argument (2 given)' Python error

Yes, when you invoke e.extractAll(foo), Python munges that into extractAll(e, foo).


the special thing about methods is that the object is passed as the first argument of the function. In our example, the call x.f() is exactly equivalent to MyClass.f(x). In general, calling a method with a list of n arguments is equivalent to calling the corresponding function with an argument list that is created by inserting the method’s object before the first argument.

Emphasis added.

MySQL Data Source not appearing in Visual Studio

From the MySql site.

Starting with version 6.7, Connector/Net will no longer include the MySQL for Visual Studio integration. That functionality is now available in a separate product called MySQL for Visual Studio available using the MySQL Installer for Windows (see

Generating a PNG with matplotlib when DISPLAY is undefined

import matplotlib
import matplotlib.pyplot as plt

It works for me.

Access Control Origin Header error using Axios in React Web throwing error in Chrome

If your backend support CORS, you probably need to add to your request this header:

headers: {"Access-Control-Allow-Origin": "*"}

[Update] Access-Control-Allow-Origin is a response header - so in order to enable CORS - you need to add this header to the response from your server.

But for the most cases better solution would be configuring the reverse proxy, so that your server would be able to redirect requests from the frontend to backend, without enabling CORS.

You can find documentation about CORS mechanism here:

How to detect a remote side socket close?

Since the answers deviate I decided to test this and post the result - including the test example.

The server here just writes data to a client and does not expect any input.

The server:

ServerSocket serverSocket = new ServerSocket(4444);
Socket clientSocket = serverSocket.accept();
PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
while (true) {
  if (out.checkError()) System.out.println("ERROR writing data to socket !!!");
        // thread sleep ...
  // break condition , close sockets and the like ...
  • clientSocket.isConnected() returns always true once the client connects (and even after the disconnect) weird !!
  • getInputStream().read()
    • makes the thread wait for input as long as the client is connected and therefore makes your program not do anything - except if you get some input
    • returns -1 if the client disconnected
  • out.checkError() is true as soon as the client is disconnected so I recommend this

Apply style to parent if it has child with css

It's not possible with CSS3. There is a proposed CSS4 selector, $, to do just that, which could look like this (Selecting the li element):

ul $li ul.sub { ... }

See the list of CSS4 Selectors here.

As an alternative, with jQuery, a one-liner you could make use of would be this:

$('ul li:has(ul.sub)').addClass('has_sub');

You could then go ahead and style the li.has_sub in your CSS.

How to break a while loop from an if condition inside the while loop?

do something...
   if(contains something to process){
      do something...

Just use the break statement;

For eg:this just prints "Breaking..."

while (true) {
     if (true) {
     System.out.println("Did this print?");

VBA EXCEL Multiple Nested FOR Loops that Set two variable for expression

I can't get to your google docs file at the moment but there are some issues with your code that I will try to address while answering

Sub stituterangersNEW()
Dim t As Range
Dim x As Range
Dim dify As Boolean
Dim difx As Boolean
Dim time2 As Date
Dim time1 As Date

    'You said time1 doesn't change, so I left it in a singe cell.
    'If that is not correct, you will have to play with this some more.
    time1 = Range("A6").Value

    'Looping through each of our output cells.
    For Each t In Range("B7:E9") 'Change these to match your real ranges.

        'Looping through each departure date/time.
        '(Only one row in your example. This can be adjusted if needed.)
        For Each x In Range("B2:E2") 'Change these to match your real ranges.
            'Check to see if our dep time corresponds to
            'the matching column in our output
            If t.Column = x.Column Then
                'If it does, then check to see what our time value is
                If x > 0 Then
                    time2 = x.Value
                    'Apply the change to the output cell.
                    t.Value = time1 - time2
                    'Exit out of this loop and move to the next output cell.
                    Exit For
                End If
            End If
            'If the columns don't match, or the x value is not a time
            'then we'll move to the next dep time (x)
        Next x
    Next t

End Sub


I changed you worksheet to play with (see above for the new Sub). This probably does not suite your needs directly, but hopefully it will demonstrate the conept behind what I think you want to do. Please keep in mind that this code does not follow all the coding best preactices I would recommend (e.g. validating the time is actually a TIME and not some random other data type).

     A                      B                   C                   D                  E
1    LOAD_NUMBER            1                   2                   3                  4
2    DEPARTURE_TIME_DATE    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 20:00                
4    Dry_Refrig 7585.1  0   10099.8 16700
6    1/4/2012 19:30

Using the sub I got this output:

    A           B             C             D             E
7   Friday      1272:00:00    1272:00:00    1272:00:00    1271:30:00
8   Saturday    1272:00:00    1272:00:00    1272:00:00    1271:30:00
9   Thursday    1272:00:00    1272:00:00    1272:00:00    1271:30:00

How do you simulate Mouse Click in C#?

they are some needs i can't see to dome thing like Keith or Marcos Placona did instead of just doing

using System;
using System.Windows.Forms;

namespace WFsimulateMouseClick
    public partial class Form1 : Form
        public Form1()

        private void Form1_Load(object sender, EventArgs e)
            button1_Click(button1, new MouseEventArgs(System.Windows.Forms.MouseButtons.Left, 1, 1, 1, 1));

            //by the way
            // and
            //button1_Click(button1, new EventArgs());
            // are the same

        private void button1_Click(object sender, EventArgs e)

Mac OS X - EnvironmentError: mysql_config not found

This answer is for MacOS users who did not install from brew but rather from the official .dmg/.pkg. That installer fails to edit your PATH, causing things to break out of the box:

  1. All MySQL commands like mysql, mysqladmin, mysql_config, etc cannot be found, and as a result:
  2. the "MySQL Preference Pane" fails to appear in System Preferences, and
  3. you cannot install any API that communicates with MySQL, including mysqlclient

What you have to do is appending the MySQL bin folder (typically /usr/local/mysql/bin in your PATH by adding this line in your ~/.bash_profile file:

export PATH="/usr/local/mysql/bin/:$PATH"

You should then reload your ~/.bash_profile for the change to take effect in your current Terminal session:

source ~/.bash_profile

Before installing mysqlclient, however, you need to accept the XcodeBuild license:

sudo xcodebuild -license

Follow their directions to sign away your family, after which you should be able to install mysqlclient without issue:

pip install mysqlclient

After installing that, you must do one more thing to fix a runtime bug that ships with MySQL (Dynamic Library libmysqlclient.dylib not found), by adding this line to your system dynamic libraries path:

export DYLD_LIBRARY_PATH=/usr/local/mysql/lib/:$DYLD_LIBRARY_PATH

How is the 'use strict' statement interpreted in Node.js?

"use strict";

Basically it enables the strict mode.

Strict Mode is a feature that allows you to place a program, or a function, in a "strict" operating context. In strict operating context, the method form binds this to the objects as before. The function form binds this to undefined, not the global set objects.

As per your comments you are telling some differences will be there. But it's your assumption. The Node.js code is nothing but your JavaScript code. All Node.js code are interpreted by the V8 JavaScript engine. The V8 JavaScript Engine is an open source JavaScript engine developed by Google for Chrome web browser.

So, there will be no major difference how "use strict"; is interpreted by the Chrome browser and Node.js.

Please read what is strict mode in JavaScript.

For more information:

  1. Strict mode
  2. ECMAScript 5 Strict mode support in browsers
  3. Strict mode is coming to town
  4. Compatibility table for strict mode
  5. Stack Overflow questions: what does 'use strict' do in JavaScript & what is the reasoning behind it

ECMAScript 6:

ECMAScript 6 Code & strict mode. Following is brief from the specification:

10.2.1 Strict Mode Code

An ECMAScript Script syntactic unit may be processed using either unrestricted or strict mode syntax and semantics. Code is interpreted as strict mode code in the following situations:

  • Global code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive (see 14.1.1).
  • Module code is always strict mode code.
  • All parts of a ClassDeclaration or a ClassExpression are strict mode code.
  • Eval code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive or if the call to eval is a direct eval (see that is contained in strict mode code.
  • Function code is strict mode code if the associated FunctionDeclaration, FunctionExpression, GeneratorDeclaration, GeneratorExpression, MethodDefinition, or ArrowFunction is contained in strict mode code or if the code that produces the value of the function’s [[ECMAScriptCode]] internal slot begins with a Directive Prologue that contains a Use Strict Directive.
  • Function code that is supplied as the arguments to the built-in Function and Generator constructors is strict mode code if the last argument is a String that when processed is a FunctionBody that begins with a Directive Prologue that contains a Use Strict Directive.

Additionally if you are lost on what features are supported by your current version of Node.js, this can help you (leverages from the same data as kangax).

What is the functionality of setSoTimeout and how it works?

The JavaDoc explains it very well:

With this option set to a non-zero timeout, a read() call on the InputStream associated with this Socket will block for only this amount of time. If the timeout expires, a is raised, though the Socket is still valid. The option must be enabled prior to entering the blocking operation to have effect. The timeout must be > 0. A timeout of zero is interpreted as an infinite timeout.

SO_TIMEOUT is the timeout that a read() call will block. If the timeout is reached, a will be thrown. If you want to block forever put this option to zero (the default value), then the read() call will block until at least 1 byte could be read.

Use JAXB to create Object from XML String

There is no unmarshal(String) method. You should use a Reader:

Person person = (Person) unmarshaller.unmarshal(new StringReader("xml string"));

But usually you are getting that string from somewhere, for example a file. If that's the case, better pass the FileReader itself.

How to express a One-To-Many relationship in Django

In Django, a one-to-many relationship is called ForeignKey. It only works in one direction, however, so rather than having a number attribute of class Dude you will need

class Dude(models.Model):

class PhoneNumber(models.Model):
    dude = models.ForeignKey(Dude)

Many models can have a ForeignKey to one other model, so it would be valid to have a second attribute of PhoneNumber such that

class Business(models.Model):
class Dude(models.Model):
class PhoneNumber(models.Model):
    dude = models.ForeignKey(Dude)
    business = models.ForeignKey(Business)

You can access the PhoneNumbers for a Dude object d with d.phonenumber_set.objects.all(), and then do similarly for a Business object.

Laravel - htmlspecialchars() expects parameter 1 to be string, object given

When you use a blade echo {{ $data }} it will automatically escape the output. It can only escape strings. In your data $data->ac is an array and $data is an object, neither of which can be echoed as is. You need to be more specific of how the data should be outputted. What exactly that looks like entirely depends on what you're trying to accomplish. For example to display the link you would need to do {{ $data->ac[0][0]['url'] }} (not sure why you have two nested arrays but I'm just following your data structure).

@foreach($data->ac['0'] as $link)
    <a href="{{ $link['url'] }}">This is a link</a>

Trying to get the average of a count resultset

You just can put your query as a subquery:

SELECT avg(count)
    SELECT COUNT (*) AS Count
      FROM Table T
     WHERE T.Update_time =
               (SELECT MAX (B.Update_time )
                  FROM Table B
                 WHERE (B.Id = T.Id))
    GROUP BY T.Grouping
    ) as counts

Edit: I think this should be the same:

SELECT count(*) / count(distinct T.Grouping)
  FROM Table T
 WHERE T.Update_time =
           (SELECT MAX (B.Update_time)
              FROM Table B
             WHERE (B.Id = T.Id))

How to create a simple checkbox in iOS?

On iOS there is the switch UI component instead of a checkbox, look into the UISwitch class. The property on (boolean) can be used to determine the state of the slider and about the saving of its state: That depends on how you save your other stuff already, its just saving a boolean value.

Rounding up to next power of 2

Despite the question is tagged as c here my five cents. Lucky us, C++ 20 would include std::ceil2 and std::floor2 (see here). It is consexpr template functions, current GCC implementation uses bitshifting and works with any integral unsigned type.

jQuery Event : Detect changes to the html/text of a div

Use MutationObserver as seen in this snippet provided by Mozilla, and adapted from this blog post

Alternatively, you can use the JQuery example seen in this link

Chrome 18+, Firefox 14+, IE 11+, Safari 6+

// Select the node that will be observed for mutations
var targetNode = document.getElementById('some-id');

// Options for the observer (which mutations to observe)
var config = { attributes: true, childList: true };

// Callback function to execute when mutations are observed
var callback = function(mutationsList) {
    for(var mutation of mutationsList) {
        if (mutation.type == 'childList') {
            console.log('A child node has been added or removed.');
        else if (mutation.type == 'attributes') {
            console.log('The ' + mutation.attributeName + ' attribute was modified.');

// Create an observer instance linked to the callback function
var observer = new MutationObserver(callback);

// Start observing the target node for configured mutations
observer.observe(targetNode, config);

// Later, you can stop observing


You can use ORDER BY inside the GROUP_CONCAT function in this way:

SELECT li.client_id, group_concat(li.percentage ORDER BY li.views ASC) AS views, 
group_concat(li.percentage ORDER BY li.percentage ASC) 
FROM li GROUP BY client_id

Plotting multiple time series on the same plot using ggplot()

If both data frames have the same column names then you should add one data frame inside ggplot() call and also name x and y values inside aes() of ggplot() call. Then add first geom_line() for the first line and add second geom_line() call with data=df2 (where df2 is your second data frame). If you need to have lines in different colors then add color= and name for eahc line inside aes() of each geom_line().


ggplot(df1,aes(x,y))+geom_line(aes(color="First line"))+
  geom_line(data=df2,aes(color="Second line"))+
  labs(color="Legend text")

enter image description here

Bootstrap trying to load map file. How to disable it? Do I need to do it?

Delete the line "/*# */ " in following files.

  • css/bootstrap.min.css
  • css/bootstrap.css

To fetch the file path in Linux use the command find / -name "\*bootstrap\*"

How do I remove all HTML tags from a string without knowing which tags are in it?

You can use the below code on your string and you will get the complete string without html part.

string title = "<b> Hulk Hogan's Celebrity Championship Wrestling &nbsp;&nbsp;&nbsp;<font color=\"#228b22\">[Proj # 206010]</font></b>&nbsp;&nbsp;&nbsp; (Reality Series, &nbsp;)".Replace("&nbsp;",string.Empty);            
        string s = Regex.Replace(title, "<.*?>", String.Empty);

Python, creating objects

Objects are instances of classes. Classes are just the blueprints for objects. So given your class definition -

# Note the added (object) - this is the preferred way of creating new classes
class Student(object):
    name = "Unknown name"
    age = 0
    major = "Unknown major"

You can create a make_student function by explicitly assigning the attributes to a new instance of Student -

def make_student(name, age, major):
    student = Student() = name
    student.age = age
    student.major = major
    return student

But it probably makes more sense to do this in a constructor (__init__) -

class Student(object):
    def __init__(self, name="Unknown name", age=0, major="Unknown major"): = name
        self.age = age
        self.major = major

The constructor is called when you use Student(). It will take the arguments defined in the __init__ method. The constructor signature would now essentially be Student(name, age, major).

If you use that, then a make_student function is trivial (and superfluous) -

def make_student(name, age, major):
    return Student(name, age, major)

For fun, here is an example of how to create a make_student function without defining a class. Please do not try this at home.

def make_student(name, age, major):
    return type('Student', (object,),
                {'name': name, 'age': age, 'major': major})()

.gitignore for Visual Studio Projects and Solutions

For those interested in what Microsoft thinks should be included in the gitignore, here's the default one which Visual Studio 2013 RTM automatically generates when creating a new Git-Repository:

## Ignore Visual Studio temporary files, build results, and
## files generated by popular Visual Studio add-ons.

# User-specific files

# Build results


# Enable "build/" folder in the NuGet Packages folder since NuGet packages use it for MSBuild targets

# MSTest test Results


# Visual C++ cache files

# Visual Studio profiler

# Guidance Automation Toolkit

# ReSharper is a .NET coding add-in

# TeamCity is a build add-in

# DotCover is a Code Coverage Tool

# NCrunch

# Installshield output folder

# DocProject is a documentation generator add-in

# Click-Once directory

# Publish Web Output

# NuGet Packages Directory
## TODO: If you have NuGet Package Restore enabled, uncomment the next line

# Windows Azure Build Output

# Windows Store app package directory

# Others

# RIA/Silverlight projects

# Backup & report files from converting an old project file to a newer
# Visual Studio version. Backup files are not needed, because we have git ;-)

# SQL Server files

#LightSwitch generated files

# =========================
# Windows detritus
# =========================

# Windows image file caches

# Folder config file

# Recycle Bin used on file shares

# Mac desktop service store files

See: Add a default .gitignore file on MSDN

Count number of rows within each group

Current best practice (tidyverse) is:

df1 %>% count(Year, Month)

Get list of filenames in folder with Javascript

I use the following (stripped-down code) in Firefox 69.0 (on Ubuntu) to read a directory and show the image as part of a digital photo frame. The page is made in HTML, CSS, and JavaScript, and it is located on the same machine where I run the browser. The images are located on the same machine as well, so there is no viewing from "outside".

var directory = <path>;
var xmlHttp = new XMLHttpRequest();'GET', directory, false); // false for synchronous request
var ret = xmlHttp.responseText;
var fileList = ret.split('\n');
for (i = 0; i < fileList.length; i++) {
    var fileinfo = fileList[i].split(' ');
    if (fileinfo[0] == '201:') {
        document.write(fileinfo[1] + "<br>");
        document.write('<img src=\"' + directory + fileinfo[1] + '\"/>');

This requires the policy security.fileuri.strict_origin_policy to be disabled. This means it might not be a solution you want to use. In my case I deemed it ok.

Where does Android app package gets installed on phone

An application when installed on a device or on an emulator will install at:


The APK itself is placed in the /data/app/ folder.

These paths, however, are in the System Partition and to access them, you will need to have root. This is for a device. On the emulator, you can see it in your logcat (DDMS) in the File Explorer tab

By the way, it only shows the package name that is defined in your Manifest.XML under the package="APP_PACKAGE_NAME" attribute. Any other packages you may have created in your project in Eclipse do not show up here.

WPF TabItem Header Styling

While searching for a way to round tabs, I found Carlo's answer and it did help but I needed a bit more. Here is what I put together, based on his work. This was done with MS Visual Studio 2015.

The Code:

<Window x:Class="MainWindow"
        Title="Rounded Tabs Example" Height="550" Width="700" WindowStartupLocation="CenterScreen" FontFamily="DokChampa" FontSize="13.333" ResizeMode="CanMinimize" BorderThickness="0">
        <DropShadowEffect Opacity="0.5"/>
    <Grid Background="#FF423C3C">
        <TabControl x:Name="tabControl" TabStripPlacement="Left" Margin="6,10,10,10" BorderThickness="3">
                <Style TargetType="{x:Type TabItem}">
                    <Setter Property="Template">
                            <ControlTemplate TargetType="{x:Type TabItem}">
                                    <Border Name="Border" Background="#FF6E6C67" Margin="2,2,-8,0" BorderBrush="Black" BorderThickness="1,1,1,1" CornerRadius="10">
                                        <ContentPresenter x:Name="ContentSite" ContentSource="Header" VerticalAlignment="Center" HorizontalAlignment="Center" Margin="2,2,12,2" RecognizesAccessKey="True"/>
                                    <Rectangle Height="100" Width="10" Margin="0,0,-10,0" Stroke="Black" VerticalAlignment="Bottom" HorizontalAlignment="Right" StrokeThickness="0" Fill="#FFD4D0C8"/>
                                    <Trigger Property="IsSelected" Value="True">
                                        <Setter Property="FontWeight" Value="Bold" />
                                        <Setter TargetName="ContentSite" Property="Width" Value="30" />
                                        <Setter TargetName="Border" Property="Background" Value="#FFD4D0C8" />
                                    <Trigger Property="IsEnabled" Value="False">
                                        <Setter TargetName="Border" Property="Background" Value="#FF6E6C67" />
                                    <Trigger Property="IsMouseOver" Value="true">
                                        <Setter Property="FontWeight" Value="Bold" />
                    <Setter Property="HeaderTemplate">
                                <ContentPresenter Content="{TemplateBinding Content}">
                                        <RotateTransform Angle="270" />
                    <Setter Property="Background" Value="#FF6E6C67" />
                    <Setter Property="Height" Value="90" />
                    <Setter Property="Margin" Value="0" />
                    <Setter Property="Padding" Value="0" />
                    <Setter Property="FontFamily" Value="DokChampa" />
                    <Setter Property="FontSize" Value="16" />
                    <Setter Property="VerticalAlignment" Value="Top" />
                    <Setter Property="HorizontalAlignment" Value="Right" />
                    <Setter Property="UseLayoutRounding" Value="False" />
                <Style x:Key="tabGrids">
                    <Setter Property="Grid.Background" Value="#FFE5E5E5" />
                    <Setter Property="Grid.Margin" Value="6,10,10,10" />
            <TabItem Header="Planner">
                <Grid Style="{StaticResource tabGrids}"/>
            <TabItem Header="Section 2">
                <Grid Style="{StaticResource tabGrids}"/>
            <TabItem Header="Section III">
                <Grid Style="{StaticResource tabGrids}"/>
            <TabItem Header="Section 04">
                <Grid Style="{StaticResource tabGrids}"/>
            <TabItem Header="Tools">
                <Grid Style="{StaticResource tabGrids}"/>


enter image description here

Replacing objects in array

I went with this, because it makes sense to me. Comments added for readers!

masterData = [{id: 1, name: "aaaaaaaaaaa"}, 
        {id: 2, name: "Bill"},
        {id: 3, name: "ccccccccc"}];

updatedData = [{id: 3, name: "Cat"},
               {id: 1, name: "Apple"}];

updatedData.forEach(updatedObj=> {
       // For every updatedData object (dataObj), find the array index in masterData where the IDs match.
       let indexInMasterData = =>; // First make an array of IDs, to use indexOf().
       // If there is a matching ID (and thus an index), replace the existing object in masterData with the updatedData's object.
       if (indexInMasterData !== undefined) masterData.splice(indexInMasterData, 1, updatedObj);

/* masterData becomes [{id: 1, name: "Apple"}, 
                       {id: 2, name: "Bill"},
                       {id: 3, name: "Cat"}];  as you want.`*/

Align vertically using CSS 3

I always using tutorial from this article to center things. It's great

div.container3 {
   height: 10em;
   position: relative }              /* 1 */
div.container3 p {
   margin: 0;
   position: absolute;               /* 2 */
   top: 50%;                         /* 3 */
   transform: translate(0, -50%) }   /* 4 */

The essential rules are:

  1. Make the container relatively positioned, which declares it to be a container for absolutely positioned elements.
  2. Make the element itself absolutely positioned.
  3. Place it halfway down the container with 'top: 50%'. (Note that 50%' here means 50% of the height of the container.)
  4. Use a translation to move the element up by half its own height. (The '50%' in 'translate(0, -50%)' refers to the height of the element itself.)

ES6 export all values from object

Exporting each variable from your variables file. Then importing them with * as in your other file and exporting the as a constant from that file will give you a dynamic object with the named exports from the first file being attributes on the object exported from the second.


export const var1 = 'first';
export const var2 = 'second':
export const varN = 'nth';


import * as vars from './Variables';

export const Variables = vars;


import { Variables } from './Other';

Variables.var2 === 'second'

How can I count the number of elements of a given value in a matrix?

This is a very good function file available on Matlab Central File Exchange.

countmember.m link

This function file is totally vectorized and hence very quick. Plus, in comparison to the function being referred to in aioobe's answer, this function doesn't use the accumarray function, which is why this is even compatible with older versions of Matlab. Also, it works for cell arrays as well as numeric arrays.

SOLUTION : You can use this function in conjunction with the built in matlab function, "unique".

occurance_count = countmember(unique(M),M)

occurance_count will be a numeric array with the same size as that of unique(M) and the different values of occurance_count array will correspond to the count of corresponding values (same index) in unique(M).

How to determine the installed webpack version

For those who are using yarn

yarn list webpack will do the trick

$ yarn list webpack
yarn list v0.27.5
+- [email protected]
Done in 1.24s.

How to animate the change of image in an UIImageView?

[UIView transitionWithView:textFieldimageView
                    imageView.image = newImage;
                } completion:nil];

is another possibility

Comparing two .jar files

In Linux/CygWin a handy script I use at times is:

#Extract the jar (war or ear)
cd dir1
jar xvf jar-file1
for i in `ls *.class`
 javap $i > ${i}.txt #list the functions/variables etc

cd dir2
jar xvf jar-file2
for i in `ls *.class`
 javap $i > ${i}.txt #list the functions/variables etc

diff -r dir1 dir2 #diff recursively

How to control size of list-style-type disc in CSS?

Easiest way for me is to use Unicode Characters and then style them with span tags. I'm going to use inline css for the sake of the example, but you can do it whatever way you prefer.

eg. When I want to use a square bullet and control its color and size:

<li style="list-style:none;"><a href=""><span style="font-size:x-small;vertical-align:middle;">&#9608;</span>&nbsp;&nbsp;HOME</a></li>

You can find lots of unicode bullets here:

I do this because linking images for bullets seems a little unnecessary to me.

What's the best way to validate an XML file against an XSD file?

If you have a Linux-Machine you could use the free command-line tool SAXCount. I found this very usefull.

SAXCount -f -s -n my.xml

It validates against dtd and xsd. 5s for a 50MB file.

In debian squeeze it is located in the package "libxerces-c-samples".

The definition of the dtd and xsd has to be in the xml! You can't config them separately.

Trigger change event of dropdown

alternatively you can put onchange attribute on the dropdownlist itself, that onchange will call certain jquery function like this.

<input type="dropdownlist" onchange="jqueryFunc()">

<script type="text/javascript">
        //something goes here

hope this one helps you, and please note that this code is just a rough draft, not tested on any ide. thanks

How to log request and response body with Retrofit-Android?

I hope this code will help you to logging .
you just need to add interceptor in your Build.Gradle then make RetrofitClient .

First Step

Add this line to your build.gradle

 implementation 'com.squareup.okhttp3:logging-interceptor:3.4.1' 

Second Step

Make your Retrofit Client

   public class RetrofitClient {

    private Retrofit retrofit;
    private static OkHttpClient.Builder httpClient =
            new OkHttpClient.Builder();
    private static RetrofitClient instance = null;
    private static ApiServices service = null;
    private static HttpLoggingInterceptor logging =
            new HttpLoggingInterceptor();

    private RetrofitClient(final Context context) {
        httpClient.interceptors().add(new Interceptor() {
            public okhttp3.Response intercept(Interceptor.Chain chain) throws IOException {
                Request originalRequest = chain.request();
                Request.Builder builder = originalRequest.newBuilder().
                        method(originalRequest.method(), originalRequest.body());
                okhttp3.Response response = chain.proceed(;
                Do what you want
                return response;

        if (BuildConfig.DEBUG) {
            // add logging as last interceptor

        retrofit = new Retrofit.Builder().client(
        service = retrofit.create(ApiServices.class);

    public static RetrofitClient getInstance(Context context) {
        if (instance == null) {
            instance = new RetrofitClient(context);
        return instance;

    public ApiServices getApiService() {
        return service;



Converting a Date object to a calendar object

Here's your method:

public static Calendar toCalendar(Date date){ 
  Calendar cal = Calendar.getInstance();
  return cal;

Everything else you are doing is both wrong and unnecessary.

BTW, Java Naming conventions suggest that method names start with a lower case letter, so it should be: dateToCalendar or toCalendar (as shown).

OK, let's milk your code, shall we?

DateFormat formatter = new SimpleDateFormat("yyyyMMdd");
date = (Date)formatter.parse(date.toString()); 

DateFormat is used to convert Strings to Dates (parse()) or Dates to Strings (format()). You are using it to parse the String representation of a Date back to a Date. This can't be right, can it?

Bootstrap Carousel : Remove auto slide

$(document).ready(function() {
    pause: true,
    interval: 40000,

By using the above script, you will be able to move the images automaticaly

$(document).ready(function() {
    pause: true,
    interval: false,

By using the above script, auto-rotation will be blocked because interval is false

How to select count with Laravel's fluent query builder?

$count = DB::table('category_issue')->count();

will give you the number of items.

For more detailed information check Fluent Query Builder section in beautiful Laravel Documentation.

SSIS Excel Import Forcing Incorrect Column Type

Option 1. Use Visual Basic to iterate through each column and format each column as Text.

Use the Text-to-Columns menu, don't change the delimination, and change "General" to "Text"

What does the "@" symbol do in Powershell?

You can also wrap the output of a cmdlet (or pipeline) in @() to ensure that what you get back is an array rather than a single item.

For instance, dir usually returns a list, but depending on the options, it might return a single object. If you are planning on iterating through the results with a foreach-object, you need to make sure you get a list back. Here's a contrived example:

$results = @( dir c:\autoexec.bat)

One more thing... an empty array (like to initialize a variable) is denoted @().

How to set Sqlite3 to be case insensitive when string comparing?

Its working for me Perfectly. SELECT NAME FROM TABLE_NAME WHERE NAME = 'test Name' COLLATE NOCASE

Bin size in Matplotlib (Histogram)

This answer support the @ macrocosme suggestion.

I am using heat map as hist2d plot. Additionally I use cmin=0.5 for no count value and cmap for color, r represent the reverse of given color.

Describe statistics. enter image description here

# np.arange(data.min(), data.max()+binwidth, binwidth)
bin_x = np.arange(0.6, 7 + 0.3, 0.3)
bin_y = np.arange(12, 58 + 3, 3)
plt.hist2d(data=fuel_econ, x='displ', y='comb', cmin=0.5, cmap='viridis_r', bins=[bin_x, bin_y]);
plt.xlabel('Dispalcement (1)');
plt.ylabel('Combine fuel efficiency (mpg)');


enter image description here

What is the --save option for npm install?

You can also use -S, -D or -P which are equivalent of saving the package to an app dependency, a dev dependency or prod dependency. See more NPM shortcuts below:

-v: --version
-h, -?, --help, -H: --usage
-s, --silent: --loglevel silent
-q, --quiet: --loglevel warn
-d: --loglevel info
-dd, --verbose: --loglevel verbose
-ddd: --loglevel silly
-g: --global
-C: --prefix
-l: --long
-m: --message
-p, --porcelain: --parseable
-reg: --registry
-f: --force
-desc: --description
-S: --save
-P: --save-prod
-D: --save-dev
-O: --save-optional
-B: --save-bundle
-E: --save-exact
-y: --yes
-n: --yes false
ll and la commands: ls --long

This list of shortcuts can be obtained by running the following command:

$ npm help 7 config

How to make MySQL table primary key auto increment with some prefix

If you really need this you can achieve your goal with help of separate table for sequencing (if you don't mind) and a trigger.


CREATE TABLE table1_seq

Now the trigger

CREATE TRIGGER tg_table1_insert

Then you just insert rows to table1

INSERT INTO Table1 (name) 
VALUES ('Jhon'), ('Mark');

And you'll have

|      ID | NAME |
| LHPL001 | Jhon |
| LHPL002 | Mark |

Here is SQLFiddle demo

Shortcut to exit scale mode in VirtualBox

Another solution (poor one do) is exiting VM Box with saving desktop (top option), restart would bring back the screen as it was before the rescale.

Java "user.dir" property - what exactly does it mean?

user.dir is the "User working directory" according to the Java Tutorial, System Properties

How to set the initial zoom/width for a webview

I'm working with loading images for this answer and I want them to be scaled to the device's width. I find that, for older phones with versions less than API 19 (KitKat), the behavior for Brian's answer isn't quite as I like it. It puts a lot of whitespace around some images on older phones, but works on my newer one. Here is my alternative, with help from this answer: Can Android's WebView automatically resize huge images? The layout algorithm SINGLE_COLUMN is deprecated, but it works and I feel like it is appropriate for working with older webviews.

WebSettings settings = webView.getSettings();

// Image set to width of device. (Must be done differently for API < 19 (kitkat))
    if (!settings.getLayoutAlgorithm().equals(WebSettings.LayoutAlgorithm.SINGLE_COLUMN))
} else {
    if (!settings.getLoadWithOverviewMode()) settings.setLoadWithOverviewMode(true);
    if (!settings.getUseWideViewPort()) settings.setUseWideViewPort(true);

Early exit from function?

Apparently you can do this:

function myFunction() {myFunction:{
    console.log('i get executed');
    break myFunction;
    console.log('i do not get executed');

See block scopes through the use of a label:

I can't see any downsides yet. But it doesn't seem like a common use.

Derived this answer: JavaScript equivalent of PHP’s die

CSS "and" and "or"

&& works by stringing-together multiple selectors like-so:

<div class="class1 class2"></div>

  /* foo */

Another example:

<input type="radio" class="class1" />

  /* foo */

|| works by separating multiple selectors with commas like-so:

<div class="class1"></div>
<div class="class2"></div>

  /* foo */