Programs & Examples On #Form design


How to validate inputs dynamically created using ng-repeat, ng-show (angular)

This will get the name in the ng-repeat to come up seperate in the form validation.

    <input ng-model="r.QTY" class="span1" name="{{'QTY' + $index}}" ng-pattern="/^[\d]*\.?[\d]*$/" required/>

But I had trouble getting it to look up in its validation message so I had to use an ng-init to get it to resolve a variable as the object key.

    <input ng-model="r.QTY" class="span1" ng-init="name = 'QTY' + $index" name="{{name}}" ng-pattern="/^[\d]*\.?[\d]*$/" required/>
    <span class="alert-error" ng-show="form[name].$error.pattern"><strong>Requires a number.</strong></span>
    <span class="alert-error" ng-show="form[name].$error.required"><strong>*Required</strong></span> 

How do I view the SQL generated by the Entity Framework?

SQL Management Studio => Tools => SQL Server profiler

File => New Trace...

Use the Template => Blank

Event selection => T-SQL

Lefthandside check for: SP.StmtComplete

Column filters can be used to select a specific ApplicationName or DatabaseName

Start that profile running then trigger the query.

Click here for Source information

Django, creating a custom 500/404 error page

As one single line (for 404 generic page):

from django.shortcuts import render_to_response
from django.template import RequestContext

return render_to_response('error/404.html', {'exception': ex},
                                      context_instance=RequestContext(request), status=404)

Angular 4 setting selected option in Dropdown

If you want to select a value as default, in your form builder give it a value :

this.myForm ={
    mySelect: [this.options[0].key, [/* Validators here */]]

Now in your HTML :

<form [formGroup]="myForm">
    <select [formControlName]="mySelect">
        <option *ngFor="let opt of options" [value]="opt.key">ANY TEXT YOU WANT HERE</option>

What my code does is giving your select a value, that is equal to the first value of your options list. This is how you select an option as default in Angular, selected is useless.

Getting values from query string in an url using AngularJS $location

My fix is more simple, create a factory, and implement as one variable. For example

angular.module('myApp', [])_x000D_
// This a searchCustom factory. Copy the factory and implement in the controller_x000D_
.factory("searchCustom", function($http,$log){    _x000D_
    return {_x000D_
        valuesParams : function(params){_x000D_
            paramsResult = [];_x000D_
            params = params.replace('(', '').replace(')','').split("&");_x000D_
            for(x in params){_x000D_
                paramsKeyTmp = params[x].split("=");_x000D_
                // Si el parametro esta disponible anexamos al vector paramResult_x000D_
                if (paramsKeyTmp[1] !== '' && paramsKeyTmp[1] !== ' ' && _x000D_
                    paramsKeyTmp[1] !== null){          _x000D_
            return paramsResult;_x000D_
.controller("SearchController", function($scope, $http,$routeParams,$log,searchCustom){_x000D_
    $ctrl = this;_x000D_
    var valueParams = searchCustom.valuesParams($routeParams.value);_x000D_
    valueParams = valueParams.join('&');_x000D_
        method : "GET",_x000D_
        url: webservice+"q?"+valueParams_x000D_
    }).then( function successCallback(response){_x000D_
        data =;_x000D_
        $scope.cantEncontrados = data.length; _x000D_
        $scope.dataSearch = data;_x000D_
    } , function errorCallback(response){_x000D_
<body ng-app="myApp">_x000D_
<div ng-controller="SearchController">_x000D_
<form action="#" >_x000D_
                            <input ng-model="param1" _x000D_
                                   placeholder="param1" />_x000D_
                            <input  ng-model="param2" _x000D_
<!-- Implement in the html code _x000D_
(param1={{param1}}&param2={{param2}}) -> this is a one variable, the factory searchCustom split and restructure in the array params_x000D_
-->          _x000D_
                        <a href="#seach/(param1={{param1}}&param2={{param2}})">_x000D_
                            <buttom ng-click="searchData()" >Busqueda</buttom>_x000D_
                    </form> _x000D_

Adjust list style image position?

Here's what I did to get small grey blocks to be on the left side and in the center of the text with an increased lineheight:

background-position:left center;

Hope this helps someone :D

Detecting when Iframe content has loaded (Cross browser)

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

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

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

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

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

The ways out of load-races are:

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

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

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

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

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

Can an Android App connect directly to an online mysql database

you can definitely make such application, you need to make http conection to the database, by calling a php script which will in response run specific queries according to your project, and generated the result in the form of xml, or json formate , whihc can be displayed on your android application!. for complete tutorial on how to connect android application to mysql i would recommend to check out this tutorila

C++ undefined reference to defined function

As Paul said, this can be a linker complaint, rather than a compiler error. If you read your build output/logs carefully (may need to look in a separate IDE window to see the full details) you can dell if the problem is from the compiler (needs to be fixed in code) or from the linker (and need to be fixed in the make/cmake/project level to include a missing lib).

running multiple bash commands with subprocess

You have to use shell=True in subprocess and no shlex.split:

def subprocess_cmd(command):
    process = subprocess.Popen(command,stdout=subprocess.PIPE, shell=True)
    proc_stdout = process.communicate()[0].strip()
    print proc_stdout

subprocess_cmd('echo a; echo b')



Input type DateTime - Value format?

This works for setting the value of the INPUT:

strftime('%Y-%m-%dT%H:%M:%S', time())

Mongoose's find method with $or condition does not work properly

According to mongoDB documentation: "...That is, for MongoDB to use indexes to evaluate an $or expression, all the clauses in the $or expression must be supported by indexes."

So add indexes for your other fields and it will work. I had a similar problem and this solved it.

You can read more here:

C# Listbox Item Double Click Event

I know this question is quite old, but I was looking for a solution to this problem too. The accepted solution is for WinForms not WPF which I think many who come here are looking for.

For anyone looking for a WPF solution, here is a great approach (via Oskar's answer here):

private void myListBox_MouseDoubleClick(object sender, MouseButtonEventArgs e)
    DependencyObject obj = (DependencyObject)e.OriginalSource;

    while (obj != null && obj != myListBox)
        if (obj.GetType() == typeof(ListBoxItem))
             // Do something
         obj = VisualTreeHelper.GetParent(obj);

Basically, you walk up the VisualTree until you've either found a parent item that is a ListBoxItem, or you ascend up to the actual ListBox (and therefore did not click a ListBoxItem).

Windows Application has stopped working :: Event Name CLR20r3

Some times this problem arise when Application is build in one PC and try to run another PC. And also build the application with Visual Studio 2010.I have the following problem

Problem Description
    Stop Working
Problem Signature
  Problem Event Name:   CLR20r3
  Problem Signature 01: diagnosticcentermngr.exe
  Problem Signature 02:
  Problem Signature 03: 4f8c1772
  Problem Signature 04: System.Drawing
  Problem Signature 05:
  Problem Signature 06: 4a275e83
  Problem Signature 07: 7af
  Problem Signature 08: 6c
  Problem Signature 09: System.ArgumentException
  OS Version:   6.1.7600.
  Locale ID:    1033

Read our privacy statement online:

If the online privacy statement is not available, please read our privacy statement offline:

Dont worry, Please check out following link and install .net framework 4.Although my application .net properties was .net framework 2.

restart your PC and try again.

ASP.NET MVC 4 Custom Authorize Attribute with Permission Codes (without roles)

Here is a modification for the prev. answer. The main difference is when the user is not authenticated, it uses the original "HandleUnauthorizedRequest" method to redirect to login page:

   protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)

        if (filterContext.HttpContext.User.Identity.IsAuthenticated) {

            filterContext.Result = new RedirectToRouteResult(
                        new RouteValueDictionary(
                                controller = "Account",
                                action = "Unauthorised"

How to declare array of zeros in python (or an array of a certain size)

The question says "How to declare array of zeros ..." but then the sample code references the Python list:

buckets = []   # this is a list

However, if someone is actually wanting to initialize an array, I suggest:

from array import array

my_arr = array('I', [0] * count)

The Python purist might claim this is not pythonic and suggest:

my_arr = array('I', (0 for i in range(count)))

The pythonic version is very slow and when you have a few hundred arrays to be initialized with thousands of values, the difference is quite noticeable.

How to set textColor of UILabel in Swift

I don't know why but to change the text color of the labels you need to divide the value you want with 255, because it works only until 1.0.

For example a dark blue color:

label.textColor = UIColor(red: 0.0, green: 0.004, blue: 0.502, alpha: 1.0)

React Js conditionally applying class attributes

If you are using a transpiler (such as Babel or Traceur) you can use the new ES6 "template strings".

Here is the answer of @spitfire109, modified accordingly:

<div className={`btn-group pull-right ${this.props.showBulkActions ? 'shown' : 'hidden'}`}>

This approach allows you to do neat things like that, rendering either s-is-shown or s-is-hidden:

<div className={`s-${this.props.showBulkActions ? 'is-shown' : 'is-hidden'}`}>

Jboss server error : Failed to start service jboss.deployment.unit."jbpm-console.war"

Best solution: Goto jboss-as-7.1.1.Final\standalone\deployments folder and delete all existing files....

Run again your problem will be solved

Find if a textbox is disabled or not using jquery

.prop('disabled') will return a Boolean:

var isDisabled = $('textbox').prop('disabled');

Here's the fiddle:

How can I show the table structure in SQL Server query?

For recent versions of SQL Server Management Studio Write the in a query editor and Do "Alt" + "F1"

Excel how to find values in 1 column exist in the range of values in another

This is what you need:

 =NOT(ISERROR(MATCH(<cell in col A>,<column B>, 0)))  ## pseudo code

For the first cell of A, this would be:

 =NOT(ISERROR(MATCH(A2,$B$2:$B$5, 0)))

Enter formula (and drag down) as follows:

enter image description here

You will get:

enter image description here

Convert datetime value into string


  DATE_FORMAT(NOW(), '%d %m %Y') AS your_date;

org.json.simple.JSONArray cannot be cast to org.json.simple.JSONObject

JSONObject site = (JSONObject)jsonSites.get(i); // Exception happens here.

The return type of jsonSites.get(i) is JSONArray not JSONObject. Because sites have two '[', two means there are two arrays here.

What techniques can be used to speed up C++ compilation times?

Although not a "technique", I couldn't figure out how Win32 projects with many source files compiled faster than my "Hello World" empty project. Thus, I hope this helps someone like it did me.

In Visual Studio, one option to increase compile times is Incremental Linking (/INCREMENTAL). It's incompatible with Link-time Code Generation (/LTCG) so remember to disable incremental linking when doing release builds.

How do you embed binary data in XML?

You could encode the binary data using base64 and put it into a Base64 element; the below article is a pretty good one on the subject.

Handling Binary Data in XML Documents

Convert laravel object to array

foreach($yourArrayName as $object)
    $arrays[] = $object->toArray();
// Dump array with object-arrays

Or when toArray() fails because it's a stdClass

foreach($yourArrayName as $object)
    $arrays[] =  (array) $object;
// Dump array with object-arrays

Not working? Maybe you can find your answer here:

Convert PHP object to associative array

Using media breakpoints in Bootstrap 4-alpha

Bootstrap has a way of using media queries to define the different task for different sites. It uses four breakpoints.

we have extra small screen sizes which are less than 576 pixels that small in which I mean it's size from 576 to 768 pixels.

medium screen sizes take up screen size from 768 pixels up to 992 pixels large screen size from 992 pixels up to 1200 pixels.

E.g Small Text

This means that at the small screen between 576px and 768px, center the text For medium screen, change "sm" to "md" and same goes to large "lg"

When to use RabbitMQ over Kafka?

I realize that this is an old question, but one scenario where RabbitMQ might be a better choice is when dealing with data redaction.

With RabbitMQ, by default once the message has been consumed, it's deleted. With Kafka, by default, messages are kept for a week. It's common to set this to a much longer time, or even to never delete them.

While both products can be configured to retain (or not retain) messages, if CCPA or GDPR compliance is a concern, I'd go with RabbitMQ.

How is a non-breaking space represented in a JavaScript string?

&nbsp; is a HTML entity. When doing .text(), all HTML entities are decoded to their character values.

Instead of comparing using the entity, compare using the actual raw character:

var x = td.text();
if (x == '\xa0') { // Non-breakable space is char 0xa0 (160 dec)
  x = '';

Or you can also create the character from the character code manually it in its Javascript escaped form:

var x = td.text();
if (x == String.fromCharCode(160)) { // Non-breakable space is char 160
  x = '';

More information about String.fromCharCode is available here:

fromCharCode - MDC Doc Center

More information about character codes for different charsets are available here:

Windows-1252 Charset
UTF-8 Charset

Css transition from display none to display block, navigation with subnav

As you know the display property cannot be animated BUT just by having it in your CSS it overrides the visibility and opacity transitions.

The solution...just removed the display properties.

nav.main ul ul {_x000D_
  position: absolute;_x000D_
  list-style: none;_x000D_
  opacity: 0;_x000D_
  visibility: hidden;_x000D_
  padding: 10px;_x000D_
  background-color: rgba(92, 91, 87, 0.9);_x000D_
  -webkit-transition: opacity 600ms, visibility 600ms;_x000D_
  transition: opacity 600ms, visibility 600ms;_x000D_
nav.main ul li:hover ul {_x000D_
  visibility: visible;_x000D_
  opacity: 1;_x000D_
<nav class="main">_x000D_
      <a href="">Lorem</a>_x000D_
        <li><a href="">Ipsum</a>_x000D_
        <li><a href="">Dolor</a>_x000D_
        <li><a href="">Sit</a>_x000D_
        <li><a href="">Amet</a>_x000D_

Use the auto keyword in C++ STL

auto keyword is intended to use in such situation, it is absolutely safe. But unfortunately it available only in C++0x so you will have portability issues with it.

Simple CSS: Text won't center in a button

As a more brute force method that I found worked for me:

First wrap the text inside the button in a span, and then apply this css to that span

var spanStyle = {
      position: "absolute",
      top: "50%",
      left: "50%",
      transform: "translate(-50%, -50%)"

*above setup for inline styling

How to format a numeric column as phone number in SQL

I found that this works if wanting in a (123) - 456-7890 format.

UPDATE table 
SET Phone_number =  '(' +  
                    SUBSTRING(Phone_number, 1, 3) 
                    + ') ' 
                    + '- ' +
                    SUBSTRING(Phone_number, 4, 3) 
                    + '-' +
                    SUBSTRING(Phone_number, 7, 4) 

File Upload with Angular Material

Another example of the solution. Will look like the following enter image description here

CodePen link there.

  <choose-file layout="row">
    <input id="fileInput" type="file" class="ng-hide">
    <md-input-container flex class="md-block">
      <input type="text" ng-model="fileName" disabled>
      <div class="hint">Select your file</div>
      <md-button id="uploadButton" class="md-fab md-mini">
        <md-icon class="material-icons">attach_file</md-icon>

.directive('chooseFile', function() {
    return {
      link: function (scope, elem, attrs) {
        var button = elem.find('button');
        var input = angular.element(elem[0].querySelector('input#fileInput'));

        button.bind('click', function() {

        input.bind('change', function(e) {
          scope.$apply(function() {
            var files =;
            if (files[0]) {
              scope.fileName = files[0].name;
            } else {
              scope.fileName = null;

Hope it helps!

Excel 2007: How to display mm:ss format not as a DateTime (e.g. 73:07)?

One convenient trick to entering elapsed times into Excel is to have two zeros and a colon before the number of minutes, details follow. For copy and paste operations into Excel without have to worry about formatting at all one can use the format 00:XX:XX where XX are two digits totaling < 60. In that case, Excel will echo 0:XX:XX in the cell contents displayed and store the data as 12:XX:XX AM. If one pastes data in a 00:XXX:XX format into Excel, or 00:XX:XX where either XX > 59 this will be converted into a fraction of a day.

For example, 00:121:12 becomes 0.0841666666666667, which if multiplied by the number of seconds in a day, 86,400, becomes 7272 s. Next, 00:21:12 would by default show 0:21:12 stored as 12:21:12 AM. Finally, 00:21:60 becomes 0.0152777777777778, also a fraction of a day.

This suggestion is made merely to avoid having to worry about specific formatting in Excel, and letting the program worry about it. Note, for Excel data internally formatted as 12:XX:XX AM one can only use certain Excel commands, for example, one can take an average. However, subtraction will only work when the result is a positive number. Such that converting times into seconds, fractions of a day, or other real number is suggested for access to more complete arithmetic operation coverage.

For example, if one has a column of mixed time formats, or times that are negative and will not display, if one changes the number formatting to General, all the times will be converted to fractions of a day.

How do I use Bash on Windows from the Visual Studio Code integrated terminal?

I had already set up lots of conda environments on WSL (Bash on Ubuntu on Windows), so I wanted to use the same Bash installation on Visual Studio Code.

To do that, I just had to specify the path of this particular Bash executable (instead of the Git-Bash) on Visual Studio Code's settings:

"": "C:\\Windows\\System32\\bash.exe"

PS: to make sure where your Ubuntu on Bash executable is installed on your Windows machine, open the Command prompt (search: cmd) and run:

where bash.exe

Properties file in python (similar to Java Properties)

This is not exactly properties but Python does have a nice library for parsing configuration files. Also see this recipe: A python replacement for java.util.Properties.

The model backing the 'ApplicationDbContext' context has changed since the database was created

Delete existing db ,create new db with same name , copy all will work

creating a random number using MYSQL

This is correct formula to find integers from i to j where i <= R <= j


Retrieving JSON Object Literal from HttpServletRequest

This is simple method to get request data from HttpServletRequest using Java 8 Stream API:

String requestData = request.getReader().lines().collect(Collectors.joining());

SQL Server: convert ((int)year,(int)month,(int)day) to Datetime

In order to be independent of the language and locale settings, you should use the ISO 8601 YYYYMMDD format - this will work on any SQL Server system with any language and regional setting in effect:

      CAST(year AS VARCHAR(4)) +
      RIGHT('0' + CAST(month AS VARCHAR(2)), 2) +
      RIGHT('0' + CAST(day AS VARCHAR(2)), 2) 

Get height and width of a layout programmatically

you can use coroutines as well, like this one :

CoroutineScope(Dispatchers.Main).launch {
        val width = view.width()
        val height= view.height()
        // do your job ....

lists and arrays in VBA

You will have to change some of your data types but the basics of what you just posted could be converted to something similar to this given the data types I used may not be accurate.

Dim DateToday As String: DateToday = Format(Date, "yyyy/MM/dd")
Dim Computers As New Collection
Dim disabledList As New Collection
Dim compArray(1 To 1) As String

'Assign data to first item in array
compArray(1) = "asdf"

'Format = Item, Key
Computers.Add "ErrorState", "Computer Name"

'Prints "ErrorState"
Debug.Print Computers("Computer Name")

Collections cannot be sorted so if you need to sort data you will probably want to use an array.

Here is a link to the outlook developer reference.

Another great site to help you get started is

Moving everything over to VBA from VB.Net is not going to be simple since not all the data types are the same and you do not have the .Net framework. If you get stuck just post the code you're stuck converting and you will surely get some help!


Sub ArrayExample()
    Dim subject As String
    Dim TestArray() As String
    Dim counter As Long

    subject = "Example"
    counter = Len(subject)

    ReDim TestArray(1 To counter) As String

    For counter = 1 To Len(subject)
        TestArray(counter) = Right(Left(subject, counter), 1)
End Sub

Get protocol, domain, and port from URL

Here is the solution I'm using:

const result = `${ window.location.protocol }//${ }`;


To add cross-browser compatibility, use the following:

const result = `${ window.location.protocol }//${ window.location.hostname + (window.location.port ? ':' + window.location.port: '') }`;

Unable to run Java GUI programs with Ubuntu

Check your X Window environment variables using the "env" command.

Calling async method synchronously

I need to call this method from a synchronously method.

It's possible with GenerateCodeAsync().Result or GenerateCodeAsync().Wait(), as the other answer suggests. This would block the current thread until GenerateCodeAsync has completed.

However, your question is tagged with , and you also left the comment:

I was hoping for a simpler solution, thinking that handled this much easier than writing so many lines of code

My point is, you should not be blocking on an asynchronous method in ASP.NET. This will reduce the scalability of your web app, and may create a deadlock (when an await continuation inside GenerateCodeAsync is posted to AspNetSynchronizationContext). Using Task.Run(...).Result to offload something to a pool thread and then block will hurt the scalability even more, as it incurs +1 more thread to process a given HTTP request.

ASP.NET has built-in support for asynchronous methods, either through asynchronous controllers (in ASP.NET MVC and Web API) or directly via AsyncManager and PageAsyncTask in classic ASP.NET. You should use it. For more details, check this answer.

How to install both Python 2.x and Python 3.x in Windows

If you can't get anything else to work, open an interpreter in whichever version you choose (I prefer using iPython) and:

import subprocess'python -flags')

This uses whichever python version you are currently operating under. Works fine for a single script, but will quickly get out of hand if there are lots of scripts you run, in which case you can always make a batch file with all of these calls inside. Not the most elegant answer, but it works.

Is there a way to make aliases for different python version a la Linux?

Add days to JavaScript Date

For those using Angular:

Just do:

$$ + 1);

Solving SharePoint Server 2010 - 503. The service is unavailable, After installation

I had trouble finding the applicationhost.config file. It was in c:\windows\System32\inetsrv\ (Server2008) or the c:\windows\System32\inetsrv\config\ (Server2008r2).

After I changed that setting, I also had to change the way IIS loads the aspnet_filter.dll. Open the IIS Manager, go under "Sites", "SharePoint - 80", in the "IIS" grouping, under the "ISAPI Filters", make sure that all of the "Executable" paths point to ...Microsoft.NET\Framework64\v#.#.####\aspnet_filter.dll. Some of mine were pointed to the \Framework\ (not 64).

You also need to restart the WWW service to reload the new settings.

Undefined Symbols for architecture x86_64: Compiling problems

There's no mystery here, the linker is telling you that you haven't defined the missing symbols, and you haven't.

Similarity::Similarity() or Similarity::~Similarity() are just missing and you have defined the others incorrectly,

void Similarity::readData(Scanner& inStream){


void readData(Scanner& inStream){

etc. etc.

The second one is a function called readData, only the first is the readData method of the Similarity class.

To be clear about this, in Similarity.h

void readData(Scanner& inStream);

but in Similarity.cpp

void Similarity::readData(Scanner& inStream){

How to show SVG file on React Native?

you can convert any SVG to a component and make it reusable.

here is my answer for the easiest way you can do it

SVG to component

$(document).on("click"... not working?

Try this:

$("#test-element").on("click" ,function() {

The document way of doing it is weird too. That would make sense to me if used for a class selector, but in the case of an id you probably just have useless DOM traversing there. In the case of the id selector, you get that element instantly.

PHP: How to get referrer URL?

Underscore. Not space.


C++ callback using class member

If you have callbacks with different parameters you can use templates as follows:
// compile with: g++ -std=c++11 myTemplatedCPPcallbacks.cpp -o myTemplatedCPPcallbacksApp

#include <functional>     // c++11

#include <iostream>        // due to: cout

using std::cout;
using std::endl;

class MyClass
        static void Callback(MyClass* instance, int x);
        int private_x;

class OtherClass
        static void Callback(OtherClass* instance, std::string str);
        std::string private_str;

class EventHandler

        template<typename T, class T2>
        void addHandler(T* owner, T2 arg2)
            cout << "\nHandler added..." << endl;
            //Let's pretend an event just occured
            owner->Callback(owner, arg2);


    EventHandler* handler;
    private_x = 4;
    handler->addHandler(this, private_x);

    EventHandler* handler;
    private_str = "moh ";
    handler->addHandler(this, private_str );

void MyClass::Callback(MyClass* instance, int x)
    cout << " MyClass::Callback(MyClass* instance, int x) ==> " 
         << 6 + x + instance->private_x << endl;

void OtherClass::Callback(OtherClass* instance, std::string private_str)
    cout << " OtherClass::Callback(OtherClass* instance, std::string private_str) ==> " 
         << " Hello " << instance->private_str << endl;

int main(int argc, char** argv)
    EventHandler* handler;
    handler = new EventHandler();
    MyClass* myClass = new MyClass();
    OtherClass* myOtherClass = new OtherClass();

Set padding for UITextField with UITextBorderStyleNone

Swift 2.0 Version:

let paddingView: UIView = UIView(frame: CGRectMake(0, 0, 5, 20))
textField.leftView = paddingView
textField.leftViewMode = UITextFieldViewMode.Always;

Npm install cannot find module 'semver'

if you are in Linux server exit from the server and re ssh

do <something> N times (declarative syntax)

Assuming we can use some ES6 syntax like the spread operator, we'll want to do something as many times as the sum of all numbers in the collection.

In this case if times is equal to [1,2,3], the total number of times will be 6, i.e. 1+2+3.

 * @param {number[]} times
 * @param {cb} function
function doTimes(times, cb) {
  // Get the sum of all the times
  const totalTimes = times.reduce((acc, time) => acc + time);
  // Call the callback as many times as the sum

doTimes([1,2,3], () => console.log('something'));
// => Prints 'something' 6 times

This post should be helpful if the logic behind constructing and spreading an array isn't apparent.

Nginx: Permission denied for nginx on Ubuntu

For me, I just changed the selinux from enforcing to permissive and then I was able to start nginx without any error.

Cassandra "no viable alternative at input"

Wrong syntax. Here you are:

insert into user_by_category (game_category,customer_id) VALUES ('Goku','12');


insert into user_by_category ("game_category","customer_id") VALUES ('Kakarot','12');

The second one is normally used for case-sensitive column names.

Open a PDF using VBA in Excel

Hope this helps. I was able to open pdf files from all subfolders of a folder and copy content to the macro enabled workbook using shell as recommended above.Please see below the code .

Sub ConsolidateWorkbooksLTD()
Dim adobeReaderPath As String
Dim pathAndFileName As String
Dim shellPathName As String
Dim fso, subFldr, subFlodr
Dim FolderPath
Dim Filename As String
Dim Sheet As Worksheet
Dim ws As Worksheet
Dim HK As String
Dim s As String
Dim J As String
Dim diaFolder As FileDialog
Dim mFolder As String
Dim Basebk As Workbook
Dim Actbk As Workbook

Application.ScreenUpdating = False

Set Basebk = ThisWorkbook

' Open the file dialog
Set diaFolder = Application.FileDialog(msoFileDialogFolderPicker)
diaFolder.AllowMultiSelect = False
MsgBox diaFolder.SelectedItems(1) & "\"
mFolder = diaFolder.SelectedItems(1) & "\"
Set diaFolder = Nothing
Set fso = CreateObject("Scripting.FileSystemObject")
Set FolderPath = fso.GetFolder(mFolder)
For Each subFldr In FolderPath.SubFolders
subFlodr = subFldr & "\"
Filename = Dir(subFldr & "\*.csv*")
Do While Len(Filename) > 0
J = Filename
J = Left(J, Len(J) - 4) & ".pdf"
   Workbooks.Open Filename:=subFldr & "\" & Filename, ReadOnly:=True
   For Each Sheet In ActiveWorkbook.Sheets
   Set Actbk = ActiveWorkbook
   s = ActiveWorkbook.Name
   HK = Left(s, Len(s) - 4)
   If InStrRev(HK, "_S") <> 0 Then
   HK = Right(HK, Len(HK) - InStrRev(HK, "_S"))
   HK = Right(HK, Len(HK) - InStrRev(HK, "_L"))
   End If
   Sheet.Copy After:=ThisWorkbook.Sheets(1)
   ActiveSheet.Name = HK

   ' Open pdf file to copy SIC Decsription
   pathAndFileName = subFlodr & J
   adobeReaderPath = "C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\AcroRd32.exe"
   shellPathName = adobeReaderPath & " """ & pathAndFileName & """"
   Call Shell( _
    pathname:=shellPathName, _
    Application.Wait Now + TimeValue("0:00:2")

    SendKeys "%vpc"
    SendKeys "^a", True
    Application.Wait Now + TimeValue("00:00:2")

    ' send key to copy
     SendKeys "^c"
    ' wait 2 secs
     Application.Wait Now + TimeValue("00:00:2")
      ' activate this workook and paste the data
        Set ws = ThisWorkbook.Sheets(HK)

        Application.Wait Now + TimeValue("00:00:3")
        Application.CutCopyMode = False
        Application.Wait Now + TimeValue("00:00:3")
       Call Shell("TaskKill /F /IM AcroRd32.exe", vbHide)
       ' send key to close pdf file
        SendKeys "^q"
       Application.Wait Now + TimeValue("00:00:3")
 Next Sheet
 Workbooks(Filename).Close SaveAs = True
 Filename = Dir()
Application.ScreenUpdating = True
End Sub

I wrote the piece of code to copy from pdf and csv to the macro enabled workbook and you may need to fine tune as per your requirement

Regards, Hema Kasturi

2D character array initialization in C

C strings are enclosed in double quotes:

const char *options[2][100];

options[0][0] = "test1";
options[1][0] = "test2";

Re-reading your question and comments though I'm guessing that what you really want to do is this:

const char *options[2] = { "test1", "test2" };

Can a website detect when you are using Selenium with chromedriver?

Additionally to the great answer of Erti-Chris Eelmaa - there's annoying window.navigator.webdriver and it is read-only. Event if you change the value of it to false it will still have true. That's why the browser driven by automated software can still be detected.


The variable is managed by the flag --enable-automation in chrome. The chromedriver launches Chrome with that flag and Chrome sets the window.navigator.webdriver to true. You can find it here. You need to add to "exclude switches" the flag. For instance (Go):

package main

import (

func main() {

caps := selenium.Capabilities{
    "browserName": "chrome",

chromeCaps := chrome.Capabilities{
    Path:            "/path/to/chrome-binary",
    ExcludeSwitches: []string{"enable-automation"},

wd, err := selenium.NewRemote(caps, fmt.Sprintf("http://localhost:%d/wd/hub", 4444))

Cannot find JavaScriptSerializer in .Net 4.0

From the first search result on google:

JavaScriptSerializer Class

Provides serialization and deserialization functionality for AJAX-enabled applications.

Inheritance Hierarchy



Namespace: System.Web.Script.Serialization

Assembly: System.Web.Extensions (in System.Web.Extensions.dll)

So, include System.Web.Extensions.dll as a reference.

How do I use installed packages in PyCharm?

On Project Explorer, you can right click on the folder where the module is contained and set as 'Source'.

It will be parsed in the Index for code completion as well as other items.

How to check if an array is empty?

you may use yourArray.length to findout number of elements in an array.

Make sure yourArray is not null before doing yourArray.length, otherwise you will end up with NullPointerException.

Disable JavaScript error in WebBrowser control

webBrowser.ScriptErrorsSuppressed = true;

How to use regex in file find

find /home/test -regextype posix-extended -regex '^.*test\.log\.[0-9]{4}-[0-9]{2}-[0-9]{2}\.zip' -mtime +3
  1. -name uses globular expressions, aka wildcards. What you want is -regex
  2. To use intervals as you intend, you need to tell find to use Extended Regular Expressions via the -regextype posix-extended flag
  3. You need to escape out the periods because in regex a period has the special meaning of any single character. What you want is a literal period denoted by \.
  4. To match only those files that are greater than 3 days old, you need to prefix your number with a + as in -mtime +3.

Proof of Concept

$ find . -regextype posix-extended -regex '^.*test\.log\.[0-9]{4}-[0-9]{2}-[0-9]{2}\.zip'

How can I filter a date of a DateTimeField in Django?

Model.objects.filter(datetime__year=2011, datetime__month=2, datetime__day=30)

How to load all the images from one of my folder into my web page, using Jquery/Javascript

Add the following script:

<script type="text/javascript">

function mlString(f) {
    return f.toString().
        replace(/^[^\/]+\/\*!?/, '');
        replace(/\*\/[^\/]+$/, '');

function run_onload() {
    console.log("Sample text for console");
    var filenames = g_FOLDER_CONTENTS.match(/\S+/g);
    var fragment = document.createDocumentFragment();
    for (var i = 0; i < filenames.length; ++i) {
        var extension = filenames[i].substring(filenames[i].length-3);
        if (extension == "png" || extension == "jpg") {

var iDiv = document.createElement('div'); = 'images';
iDiv.className = 'item';

            var image = document.createElement("img");
            image.className = "fancybox";
            image.src = "images/" + filenames[i];



then create a js file with the following:

var g_FOLDER_CONTENTS = mlString(function() { /*! 

How to remove a Gitlab project?

? Just at the bottom of your project settings .?

New version new version


  • Advanced : expand
  • Remove project

Find a commit on GitHub given the commit hash

The ability to search commits has recently been added to GitHub.

To search for a hash, just enter at least the first 7 characters in the search box. Then on the results page, click the "Commits" tab to see matching commits (but only on the default branch, usually master), or the "Issues" tab to see pull requests containing the commit.

To be more explicit you can add the hash: prefix to the search, but it's not really necessary.

There is also a REST API (at the time of writing it is still in preview).

Color different parts of a RichTextBox string

This is the modified version that I put in my code (I'm using .Net 4.5) but I think it should work on 4.0 too.

public void AppendText(string text, Color color, bool addNewLine = false)
        box.SelectionColor = color;
            ? $"{text}{Environment.NewLine}"
            : text);

Differences with original one:

  • possibility to add text to a new line or simply append it
  • no need to change selection, it works the same
  • inserted ScrollToCaret to force autoscroll
  • added suspend/resume layout calls

How to convert string to boolean php

You should be able to cast to a boolean using (bool) but I'm not sure without checking whether this works on the strings "true" and "false".

This might be worth a pop though

$myBool = (bool)"False"; 

if ($myBool) {
    //do something

It is worth knowing that the following will evaluate to the boolean False when put inside

  • the boolean FALSE itself
  • the integer 0 (zero)
  • the float 0.0 (zero)
  • the empty string, and the string "0"
  • an array with zero elements
  • an object with zero member variables (PHP 4 only)
  • the special type NULL (including unset variables)
  • SimpleXML objects created from empty tags

Everytyhing else will evaluate to true.

As descried here:

Maven build debug in Eclipse

Easiest way I find is to:

  1. Right click project

  2. Debug as -> Maven build ...

  3. In the goals field put -Dmaven.surefire.debug test

  4. In the parameters put a new parameter called forkCount with a value of 0 (previously was forkMode=never but it is deprecated and doesn't work anymore)

Set your breakpoints down and run this configuration and it should hit the breakpoint.

Use of PUT vs PATCH methods in REST API real life scenarios

A very nice explanation is here-,not%20required%20to%20be%20idempotent.

A Normal Payload- // House on plot 1 { address: 'plot 1', owner: 'segun', type: 'duplex', color: 'green', rooms: '5', kitchens: '1', windows: 20 } PUT For Updated- // PUT request payload to update windows of House on plot 1 { address: 'plot 1', owner: 'segun', type: 'duplex', color: 'green', rooms: '5', kitchens: '1', windows: 21 } Note: In above payload we are trying to update windows from 20 to 21.

Now see the PATH payload- // Patch request payload to update windows on the House { windows: 21 }

Since PATCH is not idempotent, failed requests are not automatically re-attempted on the network. Also, if a PATCH request is made to a non-existent url e.g attempting to replace the front door of a non-existent building, it should simply fail without creating a new resource unlike PUT, which would create a new one using the payload. Come to think of it, it’ll be odd having a lone door at a house address.

Send values from one form to another form

You can use this;

Form1 button1 click

private void button1_Click(object sender, EventArgs e)
    Form2 frm2 = new Form2();

And add this to Form2

public string info = "";

Form2 button1 click

private void button1_Click(object sender, EventArgs e)

    info = textBox1.Text;
    BeginInvoke(new MethodInvoker(() =>

public void Gogo()
    Form1 frm = new Form1();
    frm.Text = info;

JavaScript math, round to two decimal places

Fastest Way - faster than toFixed():


x      = .123456
result = Math.round(x * 100) / 100  // result .12


x      = .123456
result = Math.round(x * 1000) / 1000      // result .123

Generate random numbers following a normal distribution in C/C++

Box-Muller implementation:

#include <cstdlib>
#include <cmath>
#include <ctime>
#include <iostream>
using namespace std;
 // return a uniformly distributed random number
double RandomGenerator()
  return ( (double)(rand()) + 1. )/( (double)(RAND_MAX) + 1. );
 // return a normally distributed random number
double normalRandom()
  double y1=RandomGenerator();
  double y2=RandomGenerator();
  return cos(2*3.14*y2)*sqrt(-2.*log(y1));

int main(){
double sigma = 82.;
double Mi = 40.;
  for(int i=0;i<100;i++){
double x = normalRandom()*sigma+Mi;
    cout << " x = " << x << endl;
  return 0;

Missing artifact in pom.xml

I had the same issue. Jenkins's build was falling because of this error..after long hours troubleshooting.

Link to download ojdbc as per your requirement -

I have downloaded in my maven/bin location and executed the below command.

mvn install:install-file -Dfile=ojdbc8- -DartifactId=ojdbc8 -Dversion= -Dpackaging=jar



Select multiple records based on list of Id's with linq

Nice answers abowe, but don't forget one IMPORTANT thing - they provide different results!

  var idList = new int[1, 2, 2, 2, 2]; // same user is selected 4 times
  var userProfiles = _dataContext.UserProfile.Where(e => idList.Contains(e)).ToList();

This will return 2 rows from DB (and this could be correct, if you just want a distinct sorted list of users)

BUT in many cases, you could want an unsorted list of results. You always have to think about it like about a SQL query. Please see the example with eshop shopping cart to illustrate what's going on:

  var priceListIDs = new int[1, 2, 2, 2, 2]; // user has bought 4 times item ID 2
  var shoppingCart = _dataContext.ShoppingCart
                     .Join(priceListIDs, sc => sc.PriceListID, pli => pli, (sc, pli) => sc)

This will return 5 results from DB. Using 'contains' would be wrong in this case.

Replacing .NET WebBrowser control with a better browser, like Chrome?


Preview version of chromium based WebView 2 is released by the Microsoft. Now you can embed new Chromium Edge browser into a .NET application.


If you're targeting application to run on Windows 10, then now you can embed Edge browser into your .NET application by using Windows Community Toolkit.

WPF Example:

  1. Install Windows Community Toolkit Nuget Package

    Install-Package Microsoft.Toolkit.Win32.UI.Controls
  2. XAML Code

            <WPF:WebView x:Name="wvc" />
  3. CS Code:

    public partial class MainWindow : Window
      public MainWindow()
        // You can also use the Source property here or in the WPF designer
        wvc.Navigate(new Uri(""));

WinForms Example:

public partial class Form1 : Form
  public Form1()

    // You can also use the Source property here or in the designer
    webView1.Navigate(new Uri(""));

Please refer to this link for more information.

Do we need type="text/css" for <link> in HTML5

The HTML5 spec says that the type attribute is purely advisory and explains in detail how browsers should act if it's omitted (too much to quote here). It doesn't explicitly say that an omitted type attribute is either valid or invalid, but you can safely omit it knowing that browsers will still react as you expect.

How to set a binding in Code?

In addition to the answer of Dyppl, I think it would be nice to place this inside the OnDataContextChanged event:

private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
    // Unforunately we cannot bind from the viewmodel to the code behind so easily, the dependency property is not available in XAML. (for some reason).
    // To work around this, we create the binding once we get the viewmodel through the datacontext.
    var newViewModel = e.NewValue as MyViewModel;

    var executablePathBinding = new Binding
        Source = newViewModel,
        Path = new PropertyPath(nameof(newViewModel.ExecutablePath))

    BindingOperations.SetBinding(LayoutRoot, ExecutablePathProperty, executablePathBinding);

We have also had cases were we just saved the DataContext to a local property and used that to access viewmodel properties. The choice is of course yours, I like this approach because it is more consistent with the rest. You can also add some validation, like null checks. If you actually change your DataContext around, I think it would be nice to also call:

BindingOperations.ClearBinding(myText, TextBlock.TextProperty);

to clear the binding of the old viewmodel (e.oldValue in the event handler).

No 'Access-Control-Allow-Origin' header is present on the requested resource- AngularJS

On the client side you can enable cors requests in AngularJS via

app.config(['$httpProvider', function($httpProvider) {
        $httpProvider.defaults.useXDomain = true;
        delete $httpProvider.defaults.headers.common['X-Requested-With'];

However if this still returns an error, this would imply that the server that you are making the request has to allow CORS request and has to be configured for that.

command to remove row from a data frame

eldNew <- eld[-14,]

See ?"[" for a start ...

For ‘[’-indexing only: ‘i’, ‘j’, ‘...’ can be logical vectors, indicating elements/slices to select. Such vectors are recycled if necessary to match the corresponding extent. ‘i’, ‘j’, ‘...’ can also be negative integers, indicating elements/slices to leave out of the selection.

(emphasis added)

edit: looking around I notice How to delete the first row of a dataframe in R? , which has the answer ... seems like the title should have popped to your attention if you were looking for answers on SO?

edit 2: I also found How do I delete rows in a data frame? , searching SO for delete row data frame ...


Http Get using Android HttpURLConnection

I have created with callBack(delegate) response to Activity class.

public class WebService extends AsyncTask<String, Void, String> {

    private Context mContext;
    private OnTaskDoneListener onTaskDoneListener;
    private String urlStr = "";

    public WebService(Context context, String url, OnTaskDoneListener onTaskDoneListener) {
        this.mContext = context;
        this.urlStr = url;
        this.onTaskDoneListener = onTaskDoneListener;

    protected String doInBackground(String... params) {
        try {

            URL mUrl = new URL(urlStr);
            HttpURLConnection httpConnection = (HttpURLConnection) mUrl.openConnection();
            httpConnection.setRequestProperty("Content-length", "0");


            int responseCode = httpConnection.getResponseCode();

            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader br = new BufferedReader(new InputStreamReader(httpConnection.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line + "\n");
                return sb.toString();
        } catch (IOException e) {
        } catch (Exception ex) {
        return null;

    protected void onPostExecute(String s) {

        if (onTaskDoneListener != null && s != null) {
        } else


public interface OnTaskDoneListener {
    void onTaskDone(String responseData);

    void onError();

You can modify according to your needs. It's for get

Find Process Name by its Process ID

The basic one, ask tasklist to filter its output and only show the indicated process id information

tasklist /fi "pid eq 4444" 

To only get the process name, the line must be splitted

for /f "delims=," %%a in ('
    tasklist /fi "pid eq 4444" /nh /fo:csv
') do echo %%~a

In this case, the list of processes is retrieved without headers (/nh) in csv format (/fo:csv). The commas are used as token delimiters and the first token in the line is the image name

note: In some windows versions (one of them, my case, is the spanish windows xp version), the pid filter in the tasklist does not work. In this case, the filter over the list of processes must be done out of the command

for /f "delims=," %%a in ('
    tasklist /fo:csv /nh ^| findstr /b /r /c:"[^,]*,\"4444\","
') do echo %%~a

This will generate the task list and filter it searching for the process id in the second column of the csv output.

edited: alternatively, you can suppose what has been made by the team that translated the OS to spanish. I don't know what can happen in other locales.

tasklist /fi "idp eq 4444" 

'ls' in CMD on Windows is not recognized

Use the command dir to list all the directories and files in a directory; ls is a unix command.

jquery: get value of custom attribute

You need some form of iteration here, as val (except when called with a function) only works on the first element:


should be:

$("input[placeholder]").each( function () {
    $(this).val( $(this).attr("placeholder") );


$("input[placeholder]").val(function() {
    return $(this).attr("placeholder");

Find OpenCV Version Installed on Ubuntu

To install this product you can see this tutorial: OpenCV on Ubuntu

There are listed the packages you need. So, with:

# dpkg -l | grep libcv2
# dpkg -l | grep libhighgui2

and more listed in the url you can find which packages are installed.


# dpkg -L libcv2

you can check where are installed

This operative is used for all debian packages.

element not interactable exception in selenium web automation

you may also try full xpath, I had a similar issue where I had to click on an element which has a property javascript onclick function. the full xpath method worked and no interactable exception was thrown.

What's the "Content-Length" field in HTTP header?

It's the number of bytes of data in the body of the request or response. The body is the part that comes after the blank line below the headers.

Multiple Errors Installing Visual Studio 2015 Community Edition

I've faced the same problem with Visual Studio 2015 Community Edition Update 1. The problem in my case was, the installer somehow could not install Visual C++ Redistributable x86 version. When I checked Add Remove Programs only x64 version was installed.

If that's the case for you, you can get the missing redistributable package from here; or you can find the version appropriate to you through a google search.

Reordering arrays

You could always use the sort method, if you don't know where the record is at present:

playlist.sort(function (a, b) {
    return a.artist == "Lalo Schifrin" 
               ? 1    // Move it down the list
               : 0;   // Keep it the same

How to list installed packages from a given repo using yum

On newer versions of yum, this information is stored in the "yumdb" when the package is installed. This is the only 100% accurate way to get the information, and you can use:

yumdb search from_repo repoid

(or repoquery and grep -- don't grep yum output). However the command "find-repos-of-install" was part of yum-utils for a while which did the best guess without that information:

As floyd said, a lot of repos. include a unique "dist" tag in their release, and you can look for that ... however from what you said, I guess that isn't the case for you?

scikit-learn random state in splitting dataset

If you don't specify the random_state in your code, then every time you run(execute) your code a new random value is generated and the train and test datasets would have different values each time.

However, if a fixed value is assigned like random_state = 0 or 1 or 42 then no matter how many times you execute your code the result would be the same .i.e, same values in train and test datasets.

How to use FormData in react-native?

You can use react-native-image-picker and axios (form-data)

uploadS3 = (path) => {
    var data = new FormData();

        { uri: path, name: 'image.jpg', type: 'image/jpeg' }

    var config = {
        method: 'post',
        url: YOUR_URL,
        headers: {
            Accept: "application/json",
            "Content-Type": "multipart/form-data",
        data: data,

        .then((response) => {
        .catch((error) => {


selectPhotoTapped() {
    const options = {
        quality: 1.0,
        maxWidth: 500,
        maxHeight: 500,
        storageOptions: {
            skipBackup: true,

    ImagePicker.showImagePicker(options, response => {
        //console.log('Response = ', response);

        if (response.didCancel) {
            //console.log('User cancelled photo picker');
        } else if (response.error) {
            //console.log('ImagePicker Error: ', response.error);
        } else if (response.customButton) {
            //console.log('User tapped custom button: ', response.customButton);
        } else {
            let source = { uri: response.uri };
            // Call Upload Function

            // You can also display the image using data:
            // let source = { uri: 'data:image/jpeg;base64,' + };
                avatarSource: source,
            // this.imageUpload(source);

Daemon not running. Starting it now on port 5037

This worked for me: Open task manager (of your OS) and kill adb.exe process. Now start adb again, now adb should start normally.

How to set the focus for a particular field in a Bootstrap modal, once it appears

Bootstrap has added a loaded event.

capture the '' event on the modal

$('#mymodal').on('', function(e) {
  // do cool stuff here all day… no need to change bootstrap

Change arrow colors in Bootstraps carousel

If you just want to make them black in Bootstrap 4+.

.carousel-control-prev /*, .carousel-indicators */ {
    filter: invert(100%);

Get current time in milliseconds in Python?

If you're concerned about measuring elapsed time, you should use the monotonic clock (python 3). This clock is not affected by system clock updates like you would see if an NTP query adjusted your system time, for example.

>>> import time
>>> millis = round(time.monotonic() * 1000)

It provides a reference time in seconds that can be used to compare later to measure elapsed time.

Postgresql SELECT if string contains

In addition to the solution with 'aaaaaaaa' LIKE '%' || tag_name || '%' there are position (reversed order of args) and strpos.

SELECT id FROM TAG_TABLE WHERE strpos('aaaaaaaa', tag_name) > 0

Besides what is more efficient (LIKE looks less efficient, but an index might change things), there is a very minor issue with LIKE: tag_name of course should not contain % and especially _ (single char wildcard), to give no false positives.

Formatting a number with leading zeros in PHP

echo str_pad("1234567", 8, '0', STR_PAD_LEFT);

Setting environment variables via launchd.conf no longer works in OS X Yosemite/El Capitan/macOS Sierra/Mojave?

I added the variables in the ~/.bash_profile in the following way. After you are done restart/log out and log in

export M2_HOME=/Users/robin/softwares/apache-maven-3.2.3
export ANT_HOME=/Users/robin/softwares/apache-ant-1.9.4
launchctl setenv M2_HOME $M2_HOME
launchctl setenv ANT_HOME $ANT_HOME
export PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/Users/robin/softwares/apache-maven-3.2.3/bin:/Users/robin/softwares/apache-ant-1.9.4/bin
launchctl setenv PATH $PATH

NOTE: without restart/log out and log in you can apply these changes using;

source ~/.bash_profile

How to get value by class name in JavaScript or jquery?

Try this:

    var yourArray = [];


How to pause a vbscript execution?

With 'Enter' is better use ReadLine() or Read(2), because key 'Enter' generate 2 symbols. If user enter any text next Pause() also wil be skipped even with Read(2). So ReadLine() is better:

Sub Pause()
    WScript.Echo ("Press Enter to continue")
    z = WScript.StdIn.ReadLine()
End Sub

More examples look in

RAW POST using cURL in PHP

Implementation with Guzzle library:

use GuzzleHttp\Client;
use GuzzleHttp\RequestOptions;

$httpClient = new Client();

$response = $httpClient->post(
        RequestOptions::BODY => 'POST raw request content',
        RequestOptions::HEADERS => [
            'Content-Type' => 'application/x-www-form-urlencoded',


PHP CURL extension:

$curlHandler = curl_init();

curl_setopt_array($curlHandler, [
    CURLOPT_URL => '',

     * Specify POST method
    CURLOPT_POST => true,

     * Specify request content
    CURLOPT_POSTFIELDS => 'POST raw request content',

$response = curl_exec($curlHandler);



Source code

Code line wrapping - how to handle long lines

This is how I do it, and Google does it my way.

  • Break before the symbol for non-assignment operators.
  • Break after the symbol for = and for ,.

In your case, since you're using 120 characters, you can break it after the assignment operator resulting in

private static final Map<Class<? extends Persistent>, PersistentHelper> class2helper =
        new HashMap<Class<? extends Persistent>, PersistentHelper>();

In Java, and for this particular case, I would give two tabs (or eight spaces) after the break, depending on whether tabs or spaces are used for indentation.

This is of course a personal preference and if your project has its own convention for line-wrapping then that is what you should follow whether you like it or not.

How do I import CSV file into a MySQL table?

I know that the question is old, But I would like to share this

I Used this method to import more than 100K records (~5MB) in 0.046sec

Here's how you do it:

INTO TABLE your_awesome_table  
(field_1,field_2 , field_3);

It is very important to include the last line , if you have more than one field i.e normally it skips the last field (MySQL 5.6.17)

(field_1,field_2 , field_3);

Then, assuming you have the first row as the title for your fields, you might want to include this line also


This is what it looks like if your file has a header row.

INTO TABLE your_awesome_table  
(field_1,field_2 , field_3);

How to set time delay in javascript

Here is what I am doing to solve this issue. I agree this is because of the timing issue and needed a pause to execute the code.

var delayInMilliseconds = 1000; 
setTimeout(function() {
 //add your code here to execute
 }, delayInMilliseconds);

This new code will pause it for 1 second and meanwhile run your code.

String contains another two strings

So you want to know if one string contains two other strings?

You could use this extension which also allows to specify the comparison:

public static bool ContainsAll(this string text, StringComparison comparison = StringComparison.CurrentCulture, params string[]parts)
    return parts.All(p => text.IndexOf(p, comparison) > -1);

Use it in this way (you can also omit the StringComparison):

bool containsAll = d.ContainsAll(StringComparison.OrdinalIgnoreCase, a, b);

Sum values in a column based on date

Use pivot tables, it will definitely save you time. If you are using excel 2007+ use tables (structured references) to keep your table dynamic. However if you insist on using functions, go with Smandoli's suggestion. Again, if you are on 2007+ use SUMIFS, it's faster compared to SUMIF.

PHP: How to use array_filter() to filter array keys?

array filter function from php:

array_filter ( $array, $callback_function, $flag )

$array - It is the input array

$callback_function - The callback function to use, If the callback function returns true, the current value from array is returned into the result array.

$flag - It is optional parameter, it will determine what arguments are sent to callback function. If this parameter empty then callback function will take array values as argument. If you want to send array key as argument then use $flag as ARRAY_FILTER_USE_KEY. If you want to send both keys and values you should use $flag as ARRAY_FILTER_USE_BOTH .

For Example : Consider simple array

$array = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);

If you want to filter array based on the array key, We need to use ARRAY_FILTER_USE_KEY as third parameter of array function array_filter.

$get_key_res = array_filter($array,"get_key",ARRAY_FILTER_USE_KEY );

If you want to filter array based on the array key and array value, We need to use ARRAY_FILTER_USE_BOTH as third parameter of array function array_filter.

$get_both = array_filter($array,"get_both",ARRAY_FILTER_USE_BOTH );

Sample Callback functions:

 function get_key($key)
    if($key == 'a')
        return true;
    } else {
        return false;
function get_both($val,$key)
    if($key == 'a' && $val == 1)
        return true;
    }   else {
        return false;

It will output

Output of $get_key is :Array ( [a] => 1 ) 
Output of $get_both is :Array ( [a] => 1 ) 

preg_match(); - Unknown modifier '+'

This happened to me because I put a variable in the regex and sometimes its string value included a slash. Solution: preg_quote.

SQL Server: Examples of PIVOTing String data

Table setup:

CREATE TABLE dbo.tbl (
    action VARCHAR(20) NOT NULL,
    view_edit VARCHAR(20) NOT NULL

INSERT INTO dbo.tbl (action, view_edit)
VALUES ('Action1', 'VIEW'),
       ('Action1', 'EDIT'),
       ('Action2', 'VIEW'),
       ('Action3', 'VIEW'),
       ('Action3', 'EDIT');

Your table: SELECT action, view_edit FROM dbo.tbl

Your table

Query without using PIVOT:

SELECT Action, 
[View] = (Select view_edit FROM tbl WHERE t.action = action and view_edit = 'VIEW'),
[Edit] = (Select view_edit FROM tbl WHERE t.action = action and view_edit = 'EDIT')
FROM tbl t

Query using PIVOT:

SELECT [Action], [View], [Edit] FROM
(SELECT [Action], view_edit FROM tbl) AS t1 
PIVOT (MAX(view_edit) FOR view_edit IN ([View], [Edit]) ) AS t2

Both queries result:
enter image description here

One or more types required to compile a dynamic expression cannot be found. Are you missing references to Microsoft.CSharp.dll and System.Core.dll?

Make sure that your project is targeting the .NET framework 4.0. Visual Studio 2010 supports .NET 3.5 framework target also, but .NET 3.5 does not support the dynamic keyword.

You can adjust the framework version in the project properties. See for more info.

Do I use <img>, <object>, or <embed> for SVG files?

This jQuery function captures all errors in svg images and replaces the file extension with an alternate extension

Please open the console to see the error loading image svg

  $('img').on('error', function(){_x000D_
    var image = $(this).attr('src');_x000D_
    if ( /(\.svg)$/i.test( image )) {_x000D_
      $(this).attr('src', image.replace('.svg', '.png'));_x000D_
  })  _x000D_
<script src=""></script>_x000D_
<img src="">

JQuery show and hide div on mouse click (animate)

Use slideToggle(500) function with a duration in milliseconds for getting a better effect.

Sample Html

    <div class="growth-step js--growth-step">
        <div class="step-title">
            <div class="num">2.</div>
            <h3>How Can Aria Help Your Business</h3>
        <div class="step-details ">
            <p>At Aria solutions, we’ve taken the consultancy concept one step further by offering a full service
                management organization with expertise. </p>
    <div class="growth-step js--growth-step">
        <div class="step-title">
            <div class="num">3.</div>
            <h3>How Can Aria Help Your Business</h3>
        <div class="step-details">
            <p>At Aria solutions, we’ve taken the consultancy concept one step further by offering a full service
                management organization with expertise. </p>

In your js file, if you need child propagation for the animation then remove the second click event function and its codes.

         return false;
//for stoping child to manipulate the animation
    $(".js--growth-step .step-details").click(function(event) {

Convert base64 string to image

This assumes a few things, that you know what the output file name will be and that your data comes as a string. I'm sure you can modify the following to meet your needs:

// Needed Imports
import sun.misc.BASE64Decoder;

def sourceData = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAPAAAADwCAYAAAA+VemSAAAgAEl...==';

// tokenize the data
def parts = sourceData.tokenize(",");
def imageString = parts[1];

// create a buffered image
BufferedImage image = null;
byte[] imageByte;

BASE64Decoder decoder = new BASE64Decoder();
imageByte = decoder.decodeBuffer(imageString);
ByteArrayInputStream bis = new ByteArrayInputStream(imageByte);
image =;

// write the image to a file
File outputfile = new File("image.png");
ImageIO.write(image, "png", outputfile);

Please note, this is just an example of what parts are involved. I haven't optimized this code at all and it's written off the top of my head.

Are duplicate keys allowed in the definition of binary search trees?

Duplicate Keys • What happens if there's more than one data item with the same key? – This presents a slight problem in red-black trees. – It's important that nodes with the same key are distributed on both sides of other nodes with the same key. – That is, if keys arrive in the order 50, 50, 50, • you want the second 50 to go to the right of the first one, and the third 50 to go to the left of the first one. • Otherwise, the tree becomes unbalanced. • This could be handled by some kind of randomizing process in the insertion algorithm. – However, the search process then becomes more complicated if all items with the same key must be found. • It's simpler to outlaw items with the same key. – In this discussion we'll assume duplicates aren't allowed

One can create a linked list for each node of the tree that contains duplicate keys and store data in the list.

How do I setup the InternetExplorerDriver so it works

WebDriverManager allows to automate the management of the binary drivers (e.g. chromedriver, geckodriver, etc.) required by Selenium WebDriver.


you can use something link this: WebDriverManager.iedriver().setup();

add the following dependency for Maven:


or see:

Google OAUTH: The redirect URI in the request did not match a registered redirect URI

You need to go into the developer console and set


as your callback URL.

This video is slightly outdated, as it shows the older Developer Console instead of the new one, however, the concepts should still apply. You need to find your project in the developer console and register a callback URL.

Can I redirect the stdout in python into some sort of string buffer?

A context manager for python3:

import sys
from io import StringIO

class RedirectedStdout:
    def __init__(self):
        self._stdout = None
        self._string_io = None

    def __enter__(self):
        self._stdout = sys.stdout
        sys.stdout = self._string_io = StringIO()
        return self

    def __exit__(self, type, value, traceback):
        sys.stdout = self._stdout

    def __str__(self):
        return self._string_io.getvalue()

use like this:

>>> with RedirectedStdout() as out:
>>>     print('asdf')
>>>     s = str(out)
>>>     print('bsdf')
>>> print(s, out)
'asdf\n' 'asdf\nbsdf\n'

Set the absolute position of a view

Just to add to Andy Zhang's answer above, if you want to, you can give param to rl.addView, then make changes to it later, so:

params = new RelativeLayout.LayoutParams(30, 40);
params.leftMargin = 50;
params.topMargin = 60;
rl.addView(iv, params);

Could equally well be written as:

params = new RelativeLayout.LayoutParams(30, 40);
rl.addView(iv, params);
params.leftMargin = 50;
params.topMargin = 60;

So if you retain the params variable, you can change the layout of iv at any time after adding it to rl.

Bash script - variable content as a command to run

Your are probably looking for eval $var.

How to make button look like a link?

The code of the accepted answer works for most cases, but to get a button that really behaves like a link you need a bit more code. It is especially tricky to get the styling of focused buttons right on Firefox (Mozilla).

The following CSS ensures that anchors and buttons have the same CSS properties and behave the same on all common browsers:

button {
  align-items: normal;
  background-color: rgba(0,0,0,0);
  border-color: rgb(0, 0, 238);
  border-style: none;
  box-sizing: content-box;
  color: rgb(0, 0, 238); 
  cursor: pointer;
  display: inline;
  font: inherit;
  height: auto;
  padding: 0;
  perspective-origin: 0 0;
  text-align: start;
  text-decoration: underline;
  transform-origin: 0 0;
  width: auto;
  -moz-appearance: none;
  -webkit-logical-height: 1em; /* Chrome ignores auto, so we have to use this hack to set the correct height  */
  -webkit-logical-width: auto; /* Chrome ignores auto, but here for completeness */

/* Mozilla uses a pseudo-element to show focus on buttons, */
/* but anchors are highlighted via the focus pseudo-class. */

@supports (-moz-appearance:none) { /* Mozilla-only */
  button::-moz-focus-inner { /* reset any predefined properties */ 
    border: none;
    padding: 0;
  button:focus { /* add outline to focus pseudo-class */
    outline-style: dotted;
    outline-width: 1px;

The example above only modifies button elements to improve readability, but it can easily be extended to modify input[type="button"], input[type="submit"] and input[type="reset"] elements as well. You could also use a class, if you want to make only certain buttons look like anchors.

See this JSFiddle for a live-demo.

Please also note that this applies the default anchor-styling to buttons (e.g. blue text-color). So if you want to change the text-color or anything else of anchors & buttons, you should do this after the CSS above.

The original code (see snippet) in this answer was completely different and incomplete.

/* Obsolete code! Please use the code of the updated answer. */_x000D_
input[type="button"], input[type="button"]:focus, input[type="button"]:active,  _x000D_
button, button:focus, button:active {_x000D_
 /* Remove all decorations to look like normal text */_x000D_
 background: none;_x000D_
 border: none;_x000D_
 display: inline;_x000D_
 font: inherit;_x000D_
 margin: 0;_x000D_
 padding: 0;_x000D_
 outline: none;_x000D_
 outline-offset: 0;_x000D_
 /* Additional styles to look like a link */_x000D_
 color: blue;_x000D_
 cursor: pointer;_x000D_
 text-decoration: underline;_x000D_
/* Remove extra space inside buttons in Firefox */_x000D_
button::-moz-focus-inner {_x000D_
    border: none;_x000D_
    padding: 0;_x000D_

Get everything after the dash in a string in JavaScript

How I would do this:

// function you can use:
function getSecondPart(str) {
    return str.split('-')[1];
// use the function:

Intercept and override HTTP requests from WebView

It looks like API level 11 has support for what you need. See WebViewClient.shouldInterceptRequest().

Regex to extract substring, returning 2 results for some reason

Just get rid of the parenthesis and that will give you an array with one element and:

  • Change this line

var test = tesst.match(/a(.*)j/);

  • To this

var test = tesst.match(/a.*j/);

If you add parenthesis the match() function will find two match for you one for whole expression and one for the expression inside the parenthesis

  • Also according to docs :

If you only want the first match found, you might want to use RegExp.exec() instead.

You can use the below code:


What is pipe() function in Angular

Two very different types of Pipes Angular - Pipes and RxJS - Pipes


A pipe takes in data as input and transforms it to a desired output. In this page, you'll use pipes to transform a component's birthday property into a human-friendly date.

import { Component } from '@angular/core';

  selector: 'app-hero-birthday',
  template: `<p>The hero's birthday is {{ birthday | date }}</p>`
export class HeroBirthdayComponent {
  birthday = new Date(1988, 3, 15); // April 15, 1988

RxJS - Pipe

Observable operators are composed using a pipe method known as Pipeable Operators. Here is an example.

import {Observable, range} from 'rxjs';
import {map, filter} from 'rxjs/operators';

const source$: Observable<number> = range(0, 10);

    map(x => x * 2),
    filter(x => x % 3 === 0)
).subscribe(x => console.log(x));

The output for this in the console would be the following:





For any variable holding an observable, we can use the .pipe() method to pass in one or multiple operator functions that can work on and transform each item in the observable collection.

So this example takes each number in the range of 0 to 10, and multiplies it by 2. Then, the filter function to filter the result down to only the odd numbers.

How can I close a login form and show the main form without my application closing?

The reason your main form isn't showing is because once you close the login form, your application's message pump is shut down, which causes the entire application to exit. The Windows message loop is tied to the login form because that's the one you have set as the startup form in your project properties. Look in your "Program.cs" file, and you'll see the responsible bit of code: Application.Run(new LoginForm()). Check out the documentation for that method here on MSDN, which explains this in greater detail.

The best solution is to move the code out of your login form into the "Program.cs" file. When your program first starts, you'll create and show the login form as a modal dialog (which runs on a separate message loop and blocks execution of the rest of your code until it closes). When the login dialog closes, you'll check its DialogResult property to see if the login was successful. If it was, you can start the main form using Application.Run (thus creating the main message loop); otherwise, you can exit the application without showing any form at all. Something like this:

static void Main()
    LoginForm fLogin = new LoginForm();
    if (fLogin.ShowDialog() == DialogResult.OK)
        Application.Run(new MainForm());

Submit a form in a popup, and then close the popup

Here's how I ended up doing this:

        <div id="divform">
            <form action="/system/wpacert" method="post" enctype="multipart/form-data" name="certform">
                <div>Certificate 1: <input type="file" name="cert1"/></div>
                <div>Certificate 2: <input type="file" name="cert2"/></div>

                <div><input type="button" value="Upload" onclick="closeSelf();"/></div>
        <div  id="closelink" style="display:none">
            <a href="javascript:window.close()">Click Here to Close this Page</a>

function closeSelf(){


Where hide() and unhide() set the style.display to 'none' and 'block' respectively.

Not exactly what I had in mind, but this will have to do for the time being. Works on IE, Safari, FF and Chrome.

How do I resolve a HTTP 414 "Request URI too long" error?

Based on John's answer, I changed the GET request to a POST request. It works, without having to change the server configuration. So I went looking how to implement this. The following pages were helpful:

jQuery Ajax POST example with PHP (Note the sanitize posted data remark) and

Basically, the difference is that the GET request has the url and parameters in one string and then sends null:"GET", url+"?"+params, true);

whereas the POST request sends the url and the parameters in separate commands:"POST", url, true);

Here is a working example:


<script type="text/javascript">
    function ajaxPOSTTest() {
        try {
            // Opera 8.0+, Firefox, Safari
            ajaxPOSTTestRequest = new XMLHttpRequest();
        } catch (e) {
            // Internet Explorer Browsers
            try {
                ajaxPOSTTestRequest = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (e) {
                try {
                    ajaxPOSTTestRequest = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (e) {
                    // Something went wrong
                    alert("Your browser broke!");
                    return false;

        ajaxPOSTTestRequest.onreadystatechange = ajaxCalled_POSTTest;
        var url = "ajaxPOST.php";
        var params = "lorem=ipsum&name=binny";"POST", url, true);
        ajaxPOSTTestRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

    //Create a function that will receive data sent from the server
    function ajaxCalled_POSTTest() {
        if (ajaxPOSTTestRequest.readyState == 4) {
            document.getElementById("output").innerHTML = ajaxPOSTTestRequest.responseText;

    <button onclick="ajaxPOSTTest()">ajax POST Test</button>
    <div id="output"></div>



print $lorem.'<br>';


I just sent over 12,000 characters without any problems.

RVM is not a function, selecting rubies with 'rvm use ...' will not work

It seems like your rvm does not load ".bash_profile" properly. I have done to fix it in MAC OS X or Ubuntu 14.04 by opening terminal and write:

source ~/.rvm/scripts/rvm

List passed by ref - help me explain this behaviour

You are passing a reference to the list, but your aren't passing the list variable by reference - so when you call ChangeList the value of the variable (i.e. the reference - think "pointer") is copied - and changes to the value of the parameter inside ChangeList aren't seen by TestMethod.


private void ChangeList(ref List<int> myList) {...}
ChangeList(ref myList);

This then passes a reference to the local-variable myRef (as declared in TestMethod); now, if you reassign the parameter inside ChangeList you are also reassigning the variable inside TestMethod.

How can I remove all files in my git repo and update/push from my local git repo?

Delete all elements in repository:

 git rm -r * -f -q


 git commit -m 'Delete all the stuff'


 git push -u origin master


 Username for : "Your Username" 
 Password for : "Your Password"

How to display multiple notifications in android

You need to add a unique ID to each of the notifications so that they do not combine with each other. You can use this link for your reference :

"Logging out" of phpMyAdmin?

This happens because the current account you have used to log in probably has very limited priviledges.

To fix this problem, you can change your the AllowNoPassword config setting to false in You may also force the authentication to use the config file and specify the default username and password .

$cfg['Servers'][$i]['AllowNoPassword'] = false;
$cfg['Servers'][$i]['auth_type'] = 'config';

$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]['password'] = ''; // leave blank if no password

After this, the PhPMyAdmin login page should show up when you refresh the page. You can then log in with the default root password.

More details can be found on this post ..

"A namespace cannot directly contain members such as fields or methods"

The snippet you're showing doesn't seem to be directly responsible for the error.

This is how you can CAUSE the error:

namespace MyNameSpace

   class MyClass

If you don't immediately see what is "outside" the class, this may be due to misplaced or extra closing bracket(s) }.

How to change root logging level programmatically for logback

I think you can use MDC to change logging level programmatically. The code below is an example to change logging level on current thread. This approach does not create dependency to logback implementation (SLF4J API contains MDC).

  <turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">

How do I check if an index exists on a table field in MySQL?

show index from table_name where Column_name='column_name';

not finding android sdk (Unity)

For Mac OS Users :

Go to your Android SDK folder and delete the tools folder (I recommend you to make a copy before deleting it, in case this solution does not solve the problem for you)

Then download the tools folder here :

You can find all tools zip version here :

Then unzip the download file and place it in the Android sdk folder.

Hope it helps

Print a list of space-separated elements in Python 3

Although the accepted answer is absolutely clear, I just wanted to check efficiency in terms of time.

The best way is to print joined string of numbers converted to strings.

print(" ".join(list(map(str,l))))

Note that I used map instead of loop. I wrote a little code of all 4 different ways to compare time:

import time as t

a, b = 10, 210000
l = list(range(a, b))
tic = t.time()
for i in l:
    print(i, end=" ")

tac = t.time()
t1 = (tac - tic) * 1000
toe = t.time()
t2 = (toe - tac) * 1000
print(" ".join([str(i) for i in l]))
joe = t.time()
t3 = (joe - toe) * 1000
print(" ".join(list(map(str, l))))
toy = t.time()
t4 = (toy - joe) * 1000


Time 74344.76 71790.83 196.99 153.99

The output was quite surprising to me. Huge difference of time in cases of 'loop method' and 'joined-string method'.

Conclusion: Do not use loops for printing list if size is too large( in order of 10**5 or more).

What are the differences between json and simplejson Python modules?

json seems faster than simplejson in both cases of loads and dumps in latest version

Tested versions:

  • python: 3.6.8
  • json: 2.0.9
  • simplejson: 3.16.0


>>> def test(obj, call, data, times):
...   s =
...   print("calling: ", call, " in ", obj, " ", times, " times") 
...   for _ in range(times):
...     r = getattr(obj, call)(data)
...   e =
...   print("total time: ", str(e-s))
...   return r

>>> test(json, "dumps", data, 10000)
calling:  dumps  in  <module 'json' from 'C:\\Users\\jophine.antony\\AppData\\Local\\Programs\\Python\\Python36-32\\lib\\json\\'>   10000  times
total time:  0:00:00.054857

>>> test(simplejson, "dumps", data, 10000)
calling:  dumps  in  <module 'simplejson' from 'C:\\Users\\jophine.antony\\AppData\\Local\\Programs\\Python\\Python36-32\\lib\\site-packages\\simplejson\\'>   10000  times
total time:  0:00:00.419895
'{"1": 100, "2": "acs", "3.5": 3.5567, "d": [1, "23"], "e": {"a": "A"}}'

>>> test(json, "loads", strdata, 1000)
calling:  loads  in  <module 'json' from 'C:\\Users\\jophine.antony\\AppData\\Local\\Programs\\Python\\Python36-32\\lib\\json\\'>   1000  times
total time:  0:00:00.004985
{'1': 100, '2': 'acs', '3.5': 3.5567, 'd': [1, '23'], 'e': {'a': 'A'}}

>>> test(simplejson, "loads", strdata, 1000)
calling:  loads  in  <module 'simplejson' from 'C:\\Users\\jophine.antony\\AppData\\Local\\Programs\\Python\\Python36-32\\lib\\site-packages\\simplejson\\'>   1000  times
total time:  0:00:00.040890
{'1': 100, '2': 'acs', '3.5': 3.5567, 'd': [1, '23'], 'e': {'a': 'A'}}

For versions:

  • python: 3.7.4
  • json: 2.0.9
  • simplejson: 3.17.0

json was faster than simplejson during dumps operation but both maintained the same speed during loads operations

ADB device list is empty

This helped me at the end:

Quick guide:

  • Download Google USB Driver

  • Connect your device with Android Debugging enabled to your PC

  • Open Device Manager of Windows from System Properties.

  • Your device should appear under Other devices listed as something like Android ADB Interface or 'Android Phone' or similar. Right-click that and click on Update Driver Software...

  • Select Browse my computer for driver software

  • Select Let me pick from a list of device drivers on my computer

  • Double-click Show all devices

  • Press the Have disk button

  • Browse and navigate to [wherever your SDK has been installed]\google-usb_driver and select android_winusb.inf

  • Select Android ADB Interface from the list of device types.

  • Press the Yes button

  • Press the Install button

  • Press the Close button

Now you've got the ADB driver set up correctly. Reconnect your device if it doesn't recognize it already.

Bring a window to the front in WPF

If you are trying to hide the window, for example you minimize the window, I have found that using


will hide it correctly, then simply using


will then show the window as the top most item once again.

setting request headers in selenium

I wanted something a bit slimmer for RSpec/Ruby so that the custom code only had to live in one place. Here's my solution:

RSpec.configure do |config|
  config.after(:suite) do
    $custom_headers = nil

module RequestWithExtraHeaders
  def headers
    $custom_headers.each do |key, value|
      self.set_header "HTTP_#{key}", value
    end if $custom_headers

class ActionDispatch::Request
  prepend RequestWithExtraHeaders

Then in my specs:

$custom_headers = {"Referer" => referer_string}

Node.js request CERT_HAS_EXPIRED

Try to temporarily modify request.js and harcode everywhere rejectUnauthorized = true, but it would be better to get the certificate extended as a long-term solution.

Representing null in JSON

This is a personal and situational choice. The important thing to remember is that the empty string and the number zero are conceptually distinct from null.

In the case of a count you probably always want some valid number (unless the count is unknown or undefined), but in the case of strings, who knows? The empty string could mean something in your application. Or maybe it doesn't. That's up to you to decide.

Creating a triangle with for loops

A fun, simple solution:

for (int i = 0; i < 5; i++) 
  System.out.println("    *********".substring(i, 5 + 2*i));

Internet Explorer cache location

If it's been moved you can also (in IE 11, and I'm pretty sure this translates back to at least 10):

  • Tools - Internet Options
  • Under Browsing history click Settings
  • Under Current location it shows the directory name

Note: The View files button will open a Windows Explorer window there.

For example, mine shows C:\BrowserCache\IE\Temporary Internet Files

Using tr to replace newline with space

Best guess is you are on windows and your line ending settings are set for windows. See this topic: How to change line-ending settings

or use:

tr '\r\n' ' '

How to store array or multiple values in one column

You have a couple of questions here, so I'll address them separately:

I need to store a number of selected items in one field in a database

My general rule is: don't. This is something which all but requires a second table (or third) with a foreign key. Sure, it may seem easier now, but what if the use case comes along where you need to actually query for those items individually? It also means that you have more options for lazy instantiation and you have a more consistent experience across multiple frameworks/languages. Further, you are less likely to have connection timeout issues (30,000 characters is a lot).

You mentioned that you were thinking about using ENUM. Are these values fixed? Do you know them ahead of time? If so this would be my structure:

Base table (what you have now):

| id primary_key sequence
| -- other columns here.

Items table:

| id primary_key sequence
| descript VARCHAR(30) UNIQUE

Map table:

| base_id  bigint
| items_id bigint

Map table would have foreign keys so base_id maps to Base table, and items_id would map to the items table.

And if you'd like an easy way to retrieve this from a DB, then create a view which does the joins. You can even create insert and update rules so that you're practically only dealing with one table.

What format should I use store the data?

If you have to do something like this, why not just use a character delineated string? It will take less processing power than a CSV, XML, or JSON, and it will be shorter.

What column type should I use store the data?

Personally, I would use TEXT. It does not sound like you'd gain much by making this a BLOB, and TEXT, in my experience, is easier to read if you're using some form of IDE.

Multiple files upload in Codeigniter

public function index() {

    $user = $this->session->userdata("username");
    $file_path = "./images/" . $user . '/';

    if (isset($_FILES['multipleUpload'])) {

        if (!is_dir('images/' . $user)) {
            mkdir('./images/' . $user, 0777, TRUE);

        $files = $_FILES;
        $cpt = count($_FILES ['multipleUpload'] ['name']);

        for ($i = 0; $i < $cpt; $i ++) {

            $name = time().$files ['multipleUpload'] ['name'] [$i];
            $_FILES ['multipleUpload'] ['name'] = $name;
            $_FILES ['multipleUpload'] ['type'] = $files ['multipleUpload'] ['type'] [$i];
            $_FILES ['multipleUpload'] ['tmp_name'] = $files ['multipleUpload'] ['tmp_name'] [$i];
            $_FILES ['multipleUpload'] ['error'] = $files ['multipleUpload'] ['error'] [$i];
            $_FILES ['multipleUpload'] ['size'] = $files ['multipleUpload'] ['size'] [$i];

            if(!($this->upload->do_upload('multipleUpload')) || $files ['multipleUpload'] ['error'] [$i] !=0)
    } else {

public function set_upload_options($file_path) {
    // upload an image options
    $config = array();
    $config ['upload_path'] = $file_path;
    $config ['allowed_types'] = 'gif|jpg|png';
    return $config;

How to get number of rows inserted by a transaction

I found the answer to may previous post. Here it is.

CREATE TABLE #TempTable (id int) 

INSERT INTO @TestTable (col1, col2) OUTPUT INTO #TempTable select 1,2 

INSERT INTO @TestTable (col1, col2) OUTPUT INTO #TempTable select 3,4 

SELECT * FROM #TempTable --this select will chage @@ROWCOUNT value

Getting HTTP headers with Node.js

I had some problems with http.get; so I switched to the lib request:

var request = require('request');

var url = '';

var options = {
    url: url,
    method: 'HEAD'

request(options, function (error, response, body) {
        if (error) {
            return console.error('upload failed:', error);

        if (response.headers['content-length']) {
            var file_size = response.headers['content-length'];

Choose Git merge strategy for specific files ("ours", "mine", "theirs")

Note that git checkout --ours|--theirs will overwrite the files entirely, by choosing either theirs or ours version, which might be or might not be what you want to do (if you have any non-conflicted changes coming from the other side, they will be lost).

If instead you want to perform a three-way merge on the file, and only resolve the conflicted hunks using --ours|--theirs, while keeping non-conflicted hunks from both sides in place, you may want to resort to git merge-file; see details in this answer.

PHP string concatenation

One step (IMHO) better

$result .= $personCount . ' people';

Best way to store chat messages in a database?

You could create a database for x conversations which contains all messages of these conversations. This would allow you to add a new Database (or server) each time x exceeds. X is the number conversations your infrastructure supports (depending on your hardware,...).

The problem is still, that there may be big conversations (with a lot of messages) on the same database. e.g. you have database A and database B an each stores e.g. 1000 conversations. It my be possible that there are far more "big" conversations on server A than on server B (since this is user created content). You could add a "master" database that contains a lookup, on which database/server the single conversations can be found (or you have a schema to assign a database from hash/modulo or something).

Maybe you can find real world architectures that deal with the same problems (you may not be the first one), and that have already been solved.

Laravel Eloquent - Get one Row

You can do this too

Before you use this you must declare the DB facade in the controller Simply put this line for that

use Illuminate\Support\Facades\DB;

Now you can get a row using this

$getUserByEmail = DB::table('users')->where('email', $email)->first();

or by this too

$getUserByEmail = DB::select('SELECT * FROM users WHERE email = ?' , ['[email protected]']);

This one returns an array with only one item in it and while the first one returns an object. Keep that in mind.

Hope this helps.

What is the significance of 1/1/1753 in SQL Server?

Your great great great great great great great grandfather should upgrade to SQL Server 2008 and use the DateTime2 data type, which supports dates in the range: 0001-01-01 through 9999-12-31.

How can I create an observable with a delay

It's little late to answer ... but just in case may be someone return to this question looking for an answer

'delay' is property(function) of an Observable

fakeObservable = Observable.create(obs => {[1, 2, 3]);

This worked for me ...

What is the difference between public, private, and protected?

private - can be accessed from WITHIN the class only

protected - can be accessed from WITHIN the class and INHERITING classes

public - can be accessed from code OUTSIDE the class as well

This applies to functions as well as variables.

What __init__ and self do in Python?

  1. __init__ is basically a function which will "initialize"/"activate" the properties of the class for a specific object, once created and matched to the corresponding class..
  2. self represents that object which will inherit those properties.

Get number of digits with JavaScript

Please use the following expression to get the length of the number.

length = variableName.toString().length

Convert string with commas to array

This is easily achieved in ES6;

You can convert strings to Arrays with Array.from('string');


will console.log

['0', '1']

Which is exactly what you're looking for.

python for increment inner loop

You might just be better of using while loops rather than for loops for this. I translated your code directly from the java code.

str1 = "ababa"
str2 = "aba"
i = 0

while i < len(str1):
  j = 0
  while j < len(str2):
    if not str1[i+j] == str1[j]:
    if j == (len(str2) -1):
      i += len(str2)

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

The real limits for the alert text are not documented anywhere. The only thing the documentation says is:

In iOS 8 and later, the maximum size allowed for a notification payload is 2 kilobytes; Apple Push Notification Service refuses any notification that exceeds this limit. (Prior to iOS 8 and in OS X, the maximum payload size is 256 bytes.)

This is what I could find doing some experiments.

  • Alerts: Prior to iOS 7, the alerts display limit was 107 characters. Bigger messages were truncated and you would get a "..." at the end of the displayed message. With iOS 7 the limit seems to be increased to 235 characters. If you go over 8 lines your message will also get truncated.
  • Banners: Banners get truncated around 62 characters or 2 lines.
  • Notification Center: The messages in the notification center get truncated around 110 characters or 4 lines.
  • Lock Screen: Same as a notification center.

Just as a reminder here is a very good note from the official documentation:

If necessary, iOS truncates your message so that it fits well in each notification delivery style; for best results, you shouldn’t truncate your message.

git stash changes apply to new branch?

Since you've already stashed your changes, all you need is this one-liner:

  • git stash branch <branchname> [<stash>]

From the docs (

Creates and checks out a new branch named <branchname> starting from the commit at which the <stash> was originally created, applies the changes recorded in <stash> to the new working tree and index. If that succeeds, and <stash> is a reference of the form stash@{<revision>}, it then drops the <stash>. When no <stash> is given, applies the latest one.

This is useful if the branch on which you ran git stash save has changed enough that git stash apply fails due to conflicts. Since the stash is applied on top of the commit that was HEAD at the time git stash was run, it restores the originally stashed state with no conflicts.

Reading json files in C++

Here is another easier possibility to read in a json file:

#include "json/json.h"

std::ifstream file_input("input.json");
Json::Reader reader;
Json::Value root;
reader.parse(file_input, root);
cout << root;

You can then get the values like this:

cout << root["key"]

Padding or margin value in pixels as integer using jQuery

I probably use jquery plugin for paddings and margins in very comfortable way, Thanks...

The operation cannot be completed because the DbContext has been disposed error

Change this:

using (var dataContext = new dataContext())
    users = dataContext.Users.Where(x => x.AccountID == accountId && x.IsAdmin == false);

        ret = users.Select(x => x.ToInfo()).ToList(); 


to this:

using (var dataContext = new dataContext())
    return = dataContext.Users.Where(x => x.AccountID == accountId && x.IsAdmin == false).Select(x => x.ToInfo()).ToList();

The gist is that you only want to force the enumeration of the context dataset once. Let the caller deal with empty set scenario, as they should.

How to debug Google Apps Script (aka where does Logger.log log to?)

I am having the same problem, I found the below on the web somewhere....

Event handlers in Docs are a little tricky though. Because docs can handle multiple simultaneous edits by multiple users, the event handlers are handled server-side. The major issue with this structure is that when an event trigger script fails, it fails on the server. If you want to see the debug info you'll need to setup an explicit trigger under the triggers menu that emails you the debug info when the event fails or else it will fail silently.

python "TypeError: 'numpy.float64' object cannot be interpreted as an integer"

I came here with the same Error, though one with a different origin.

It is caused by unsupported float index in 1.12.0 and newer numpy versions even if the code should be considered as valid.

An int type is expected, not a np.float64

Solution: Try to install numpy 1.11.0

sudo pip install -U numpy==1.11.0.

What is the difference between a JavaBean and a POJO?

According to Martin Fowler a POJO is an object which encapsulates Business Logic while a Bean (except for the definition already stated in other answers) is little more than a container for holding data and the operations available on the object merely set and get data.

The term was coined while Rebecca Parsons, Josh MacKenzie and I were preparing for a talk at a conference in September 2000. In the talk we were pointing out the many benefits of encoding business logic into regular java objects rather than using Entity Beans. We wondered why people were so against using regular objects in their systems and concluded that it was because simple objects lacked a fancy name. So we gave them one, and it's caught on very nicely.

Change onclick action with a Javascript function

I recommend this approach:

Instead of having two click handlers, have only one function with a if-else statement. Let the state of the BUTTON element determine which branch of the if-else statement gets executed:


<button id="a" onclick="toggleError(this)">Button A</button>


function toggleError(button) { 
    if ( button.className === 'visible' ) {
        // HIDE ERROR
        button.className = '';
    } else {
        // SHOW ERROR
        button.className = 'visible';

Live demo:

How to test my servlet using JUnit

Updated Feb 2018: OpenBrace Limited has closed down, and its ObMimic product is no longer supported.

Here's another alternative, using OpenBrace's ObMimic library of Servlet API test-doubles (disclosure: I'm its developer).

package com.openbrace.experiments.examplecode.stackoverflow5434419;

import static org.junit.Assert.*;
import com.openbrace.experiments.examplecode.stackoverflow5434419.YourServlet;
import com.openbrace.obmimic.mimic.servlet.ServletConfigMimic;
import com.openbrace.obmimic.mimic.servlet.http.HttpServletRequestMimic;
import com.openbrace.obmimic.mimic.servlet.http.HttpServletResponseMimic;
import com.openbrace.obmimic.substate.servlet.RequestParameters;
import org.junit.Before;
import org.junit.Test;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

 * Example tests for {@link YourServlet#doPost(HttpServletRequest,
 * HttpServletResponse)}.
 * @author Mike Kaufman, OpenBrace Limited
public class YourServletTest {

    /** The servlet to be tested by this instance's test. */
    private YourServlet servlet;

    /** The "mimic" request to be used in this instance's test. */
    private HttpServletRequestMimic request;

    /** The "mimic" response to be used in this instance's test. */
    private HttpServletResponseMimic response;

     * Create an initialized servlet and a request and response for this
     * instance's test.
     * @throws ServletException if the servlet's init method throws such an
     *     exception.
    public void setUp() throws ServletException {
         * Note that for the simple servlet and tests involved:
         * - We don't need anything particular in the servlet's ServletConfig.
         * - The ServletContext isn't relevant, so ObMimic can be left to use
         *   its default ServletContext for everything.
        servlet = new YourServlet();
        servlet.init(new ServletConfigMimic());
        request = new HttpServletRequestMimic();
        response = new HttpServletResponseMimic();

     * Test the doPost method with example argument values.
     * @throws ServletException if the servlet throws such an exception.
     * @throws IOException if the servlet throws such an exception.
    public void testYourServletDoPostWithExampleArguments()
            throws ServletException, IOException {

        // Configure the request. In this case, all we need are the three
        // request parameters.
        RequestParameters parameters
            = request.getMimicState().getRequestParameters();
        parameters.set("username", "mike");
        parameters.set("password", "xyz#zyx");
        parameters.set("name", "Mike");

        // Run the "doPost".
        servlet.doPost(request, response);

        // Check the response's Content-Type, Cache-Control header and
        // body content.
        assertEquals("text/html; charset=ISO-8859-1",
        assertArrayEquals(new String[] { "no-cache" },
        assertEquals("...expected result from dataManager.register...",




  • Each "mimic" has a "mimicState" object for its logical state. This provides a clear distinction between the Servlet API methods and the configuration and inspection of the mimic's internal state.

  • You might be surprised that the check of Content-Type includes "charset=ISO-8859-1". However, for the given "doPost" code this is as per the Servlet API Javadoc, and the HttpServletResponse's own getContentType method, and the actual Content-Type header produced on e.g. Glassfish 3. You might not realise this if using normal mock objects and your own expectations of the API's behaviour. In this case it probably doesn't matter, but in more complex cases this is the sort of unanticipated API behaviour that can make a bit of a mockery of mocks!

  • I've used response.getMimicState().getContentType() as the simplest way to check Content-Type and illustrate the above point, but you could indeed check for "text/html" on its own if you wanted (using response.getMimicState().getContentTypeMimeType()). Checking the Content-Type header the same way as for the Cache-Control header also works.

  • For this example the response content is checked as character data (with this using the Writer's encoding). We could also check that the response's Writer was used rather than its OutputStream (using response.getMimicState().isWritingCharacterContent()), but I've taken it that we're only concerned with the resulting output, and don't care what API calls produced it (though that could be checked too...). It's also possible to retrieve the response's body content as bytes, examine the detailed state of the Writer/OutputStream etc.

There are full details of ObMimic and a free download at the OpenBrace website. Or you can contact me if you have any questions (contact details are on the website).

Set focus and cursor to end of text input field / string w. Jquery

You can do this using Input.setSelectionRange, part of the Range API for interacting with text selections and the text cursor:

var searchInput = $('#Search');

// Multiply by 2 to ensure the cursor always ends up at the end;
// Opera sometimes sees a carriage return as 2 characters.
var strLength = searchInput.val().length * 2;

searchInput[0].setSelectionRange(strLength, strLength);

Demo: Fiddle

create table with sequence.nextval in oracle

I for myself prefer Lukas Edger's solution.

But you might want to know there is also a function SYS_GUID which can be applied as a default value to a column and generate unique ids.

you can read more about pros and cons here

How should I print types like off_t and size_t?

As I recall, the only portable way to do it, is to cast the result to "unsigned long int" and use %lu.

printf("sizeof(int) = %lu", (unsigned long) sizeof(int));

Java double comparison epsilon

You do NOT use double to represent money. Not ever. Use java.math.BigDecimal instead.

Then you can specify how exactly to do rounding (which is sometimes dictated by law in financial applications!) and don't have to do stupid hacks like this epsilon thing.

Seriously, using floating point types to represent money is extremely unprofessional.

"git checkout <commit id>" is changing branch to "no branch"

Other answers have explained what 'detached HEAD' means. I try to answer why I want to do that. There are some cases I prefer checkout a commit than checkout a temporary branch.

  1. To compile/build at some specific commit (maybe for your daily build or just to release some specific version to test team), I used to checkout a tmp branch for that, but then I need to remember to delete the tmp branch after build. So I found checkout a commit is more convenient, after the build I just checkout to the original branch.

  2. To check what codes look like at that commit, maybe to debug an issue. The case is not much different from my case #1, I can also checkout a tmp branch for that but then I need to remember delete it. So I choose to checkout a commit more often.

  3. This is probably just me being paranoid, so I prepare to merge another branch but I already suspect I would get some merge conflict and I want to see them first before merge. So I checkout the head commit then do the merge, see the merge result. Then I git checkout -f to switch back to my branch, using -f to discard any merge conflict. Again I found it more convenient than checkout a tmp branch.

Could not connect to Redis at Connection refused with homebrew

It's the better way to connect to your redis.

At first, check the ip address of redis server like this.

ps -ef | grep redis

The result is kind of " redis 1184 1 0 .... /usr/bin/redis-server 172.x.x.x:6379

And then you can connect to redis with -h(hostname) option like this.

redis-cli -h 172.x.x.x

Comparing two .jar files

I use to ZipDiff lib (have both Java and ant API).

When to catch java.lang.Error?

Almost never. Errors are designed to be issues that applications generally can't do anything about. The only exception might be to handle the presentation of the error but even that might not go as planned depending on the error.

sql query distinct with Row_Number

Using DISTINCT causes issues as you add fields and it can also mask problems in your select. Use GROUP BY as an alternative like this:

      ,ROW_NUMBER() OVER (ORDER BY  id) AS RowNum
  FROM table
 where fid = 64
 group by id

Then you can add other interesting information from your select like this:

,count(*) as thecount


,max(description) as description

Get list of filenames in folder with Javascript

For getting the list of filenames in a specified folder, you can use:

fs.readdir(directory_path, callback_function)

This will return a list which you can parse by simple list indexing like file[0],file[1], etc.

How can I change the user on Git Bash?

For any OS

This helped me so I'll put it here, just in case. Once you are done with adding the rsa keys for both the accounts, add a config file in your .ssh directory for both the accounts (.ssh/config)

# First account
   User git
   IdentityFile ~/.ssh/id_rsa_user1
# Second account
   User git
   IdentityFile ~/.ssh/id_rsa_user2

Make sure you use the correct usernames and RSA files. Next, you can open the terminal/git bash on the repository root and check which account you would be pushing from

git config

Suppose this returns the first user email and you want to push from the second user. Change the local and :

git config "SECOND_USER"
git config "[email protected]"

(This won't change the global config and you can have the first user set up as the global user). Once done, you can confirm with git config and it should return the email of the second user. You're all set to push to GitHub with the second user. The rest is all the same old git add , git commit and git push. To push from the first user, change the local again and follow the same steps. Hope it helps :)

If the above steps are still not working for you, check to see if you have uploaded the RSA keys within GitHub portal. Refer to GitHub documentation:

Then, clear your ssh cached keys Reference

ssh-add -D

Then add you 2 ssh keys

ssh-add ~/.ssh/id_rsa_user1
ssh-add ~/.ssh/id_rsa_user2

Then type in your terminal:

ssh -T [email protected]<SECOND_ACCOUNT_USERNAME_HERE>

You should see the following output:

Hi <SECOND_USERNAME>! You've successfully authenticated, but GitHub does not provide shell access.

Then, assign the correct remote to your local repository. Make sure you put the same username as the one you gave in your .ssh/config file next to Host. In the following case [email protected]<SECOND_ACCOUNT_USERNAME_HERE>.

git remote rm origin
git remote add origin [email protected]<SECOND_ACCOUNT_USERNAME_HERE>:/your_username/your_repository.git

AWS : The config profile (MyName) could not be found

Make sure you are in the correct VirtualEnvironment. I updated PyCharm and for some reason had to point my project at my VE again. Opening the terminal, I was not in my VE when attempting zappa update (and got this error). Restarting PyCharm, all back to normal.

What is the difference between partitioning and bucketing a table in Hive ?

Before going into Bucketing, we need to understand what Partitioning is. Let us take the below table as an example. Note that I have given only 12 records in the below example for beginner level understanding. In real-time scenarios you might have millions of records.

enter image description here

Partitioning is used to obtain performance while querying the data. For example, in the above table, if we write the below sql, it need to scan all the records in the table which reduces the performance and increases the overhead.

select * from sales_table where product_id='P1'

To avoid full table scan and to read only the records related to product_id='P1' we can partition (split hive table's files) into multiple files based on the product_id column. By this the hive table's file will be split into two files one with product_id='P1' and other with product_id='P2'. Now when we execute the above query, it will scan only the product_id='P1' file.


The syntax for creating the partition is given below. Note that we should not use the product_id column definition along with the non-partitioned columns in the below syntax. This should be only in the partitioned by clause.

create table sales_table(sales_id int,trans_date date, amount int) 
partitioned by (product_id varchar(10))

Cons : We should be very careful while partitioning. That is, it should not be used for the columns where number of repeating values are very less (especially primary key columns) as it increases the number of partitioned files and increases the overhead for the Name node.

Bucketing is used to overcome the cons that I mentioned in the partitioning section. This should be used when there are very few repeating values in a column (example - primary key column). This is similar to the concept of index on primary key column in the RDBMS. In our table, we can take Sales_Id column for bucketing. It will be useful when we need to query the sales_id column.

Below is the syntax for bucketing.

create table sales_table(sales_id int,trans_date date, amount int) 
partitioned by (product_id varchar(10)) Clustered by(Sales_Id) into 3 buckets

Here we will further split the data into few more files on top of partitions.

enter image description here

Since we have specified 3 buckets, it is split into 3 files each for each product_id. It internally uses modulo operator to determine in which bucket each sales_id should be stored. For example, for the product_id='P1', the sales_id=1 will be stored in 000001_0 file (ie, 1%3=1), sales_id=2 will be stored in 000002_0 file (ie, 2%3=2),sales_id=3 will be stored in 000000_0 file (ie, 3%3=0) etc.

Granting DBA privileges to user in Oracle

You need only to write:


Because this already makes the user a DB Administrator

Can I apply the required attribute to <select> fields in HTML5?

You need to set the value attribute of option to the empty string:

<select name="status" required>
    <option selected disabled value="">what's your status?</option>
    <option value="code">coding</option>
    <option value="sleep">sleeping</option>

select will return the value of the selected option to the server when the user presses submit on the form. An empty value is the same as an empty text input -> raising the required message.


The value attribute specifies the value to be sent to a server when a form is submitted.


How to change value of a request parameter in laravel

Use merge():

    'user_id' => $modified_user_id_here,

Simple! No need to transfer the entire $request->all() to another variable.

GitHub Error Message - Permission denied (publickey)

I was having a similar problem to @Batman. However, because I was running this under /usr/local/src/projectname, running without sudo was not an option.

Just add the -E flag to preseve the environment (your ~/.ssh/ path).

$ sudo -E git clone git@your_repo

From man sudo:

-E, --preserve-env Indicates to the security policy that the user wishes to pre- serve their existing environment variables. The security policy may return an error if the user does not have permis- sion to preserve the environment.

Hide text using css

Why not simply use:

h1 { color: transparent; }

Call async/await functions in parallel

    // A generic test function that can be configured 
    // with an arbitrary delay and to either resolve or reject
    const test = (delay, resolveSuccessfully) => new Promise((resolve, reject) => setTimeout(() => {
        console.log(`Done ${ delay }`);
        resolveSuccessfully ? resolve(`Resolved ${ delay }`) : reject(`Reject ${ delay }`)
    }, delay));

    // Our async handler function
    const handler = async () => {
        // Promise 1 runs first, but resolves last
        const p1 = test(10000, true);
        // Promise 2 run second, and also resolves
        const p2 = test(5000, true);
        // Promise 3 runs last, but completes first (with a rejection) 
        // Note the catch to trap the error immediately
        const p3 = test(1000, false).catch(e => console.log(e));
        // Await all in parallel
        const r = await Promise.all([p1, p2, p3]);
        // Display the results

    // Run the handler
    Done 1000
    Reject 1000
    Done 5000
    Done 10000

Whilst setting p1, p2 and p3 is not strictly running them in parallel, they do not hold up any execution and you can trap contextual errors with a catch.

React JS get current date

Your problem is that you are naming your component class Date. When you call new Date() within your class, it won't create an instance of the Date you expect it to create (which is likely this Date)- it will try to create an instance of your component class. Then the constructor will try to create another instance, and another instance, and another instance... Until you run out of stack space and get the error you're seeing.

If you want to use Date within your class, try naming your class something different such as Calendar or DateComponent.

The reason for this is how JavaScript deals with name scope: Whenever you create a new named entity, if there is already an entity with that name in scope, that name will stop referring to the previous entity and start referring to your new entity. So if you use the name Date within a class named Date, the name Date will refer to that class and not to any object named Date which existed before the class definition started.

What is the difference between UTF-8 and ISO-8859-1?

One more important thing to realise: if you see iso-8859-1, it probably refers to Windows-1252 rather than ISO/IEC 8859-1. They differ in the range 0x80–0x9F, where ISO 8859-1 has the C1 control codes, and Windows-1252 has useful visible characters instead.

For example, ISO 8859-1 has 0x85 as a control character (in Unicode, U+0085, ``), while Windows-1252 has a horizontal ellipsis (in Unicode, U+2026 HORIZONTAL ELLIPSIS, ).

The WHATWG Encoding spec (as used by HTML) expressly declares iso-8859-1 to be a label for windows-1252, and web browsers do not support ISO 8859-1 in any way: the HTML spec says that all encodings in the Encoding spec must be supported, and no more.

Also of interest, HTML numeric character references essentially use Windows-1252 for 8-bit values rather than Unicode code points; per, &#x85; will produce U+2026 rather than U+0085.