Programs & Examples On #Chardet

chardet is a python module for encoding detection

Pipenv: Command Not Found

After installing pipenv (sudo pip install pipenv), I kept getting the "Command Not Found" error when attempting to run the pipenv shell command.

I finally fixed it with the following code:

pip3 install pipenv
pipenv shell

Pip error: Microsoft Visual C++ 14.0 is required

I got this error when I tried to install pymssql even though Visual C++ 2015 (14.0) is installed in my system.

I resolved this error by downloading the .whl file of pymssql from here.

Once downloaded, it can be installed by the following command :

pip install python_package.whl

Hope this helps

Install pip in docker

This command worked fine for me:

RUN apt-get -y install python3-pip

ImportError: No module named 'Queue'

import queue is lowercase q in Python 3.

Change Q to q and it will be fine.

(See code in for smart switching.)

ImportError: No module named sqlalchemy

This code works perfectly:

import sqlalchemy

Maybe you installed the package in another version of the interpreter?

Also, like Shawley pointed out, you need to have the flask extension installed in order for it to be accessible.

Specifying trust store information in spring boot

I was also having the same issue with Spring Boot and embedded Tomcat.

From what I understand these properties only set the Tomcat configuration parameters. According to the Tomcat documentation this is only used for Client authentication (i.e. for two-way SSL) and not for verifying remote certificates:

truststoreFile - The trust store file to use to validate client certificates.

In order to configure the trust store for HttpClient it largely depends on the HttpClient implementation you use. For instance for RestTemplate by default Spring Boot uses a SimpleClientHttpRequestFactory based on standard J2SE classes like

I've come up with a solution based on the Apache HttpClient docs and these posts:

Basically this allows for a RestTemplate bean that only trusts certificates signed by the root CA in the configured truststore.

public class RestClientConfig {

    // e.g. Add to
    private Resource trustStore;

    private char[] trustStorePassword;

    private Integer maxPoolSize;

    public ClientHttpRequestFactory httpRequestFactory() {
        return new HttpComponentsClientHttpRequestFactory(httpClient());

    public HttpClient httpClient() {

        // Trust own CA and all child certs
        Registry<ConnectionSocketFactory> socketFactoryRegistry = null;
        try {
            SSLContext sslContext = SSLContexts

            // Since only our own certs are trusted, hostname verification is probably safe to bypass
            SSLConnectionSocketFactory sslSocketFactory = new SSLConnectionSocketFactory(sslContext,
                    new HostnameVerifier() {

                        public boolean verify(final String hostname,
                                final SSLSession session) {
                            return true;

            socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
                    .register("http", PlainConnectionSocketFactory.getSocketFactory())
                    .register("https", sslSocketFactory)

        } catch (Exception e) {
            //TODO: handle exceptions

        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
        // This client is for internal connections so only one route is expected
        return HttpClientBuilder.create()

    public RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate();
        return restTemplate;

And then you can use this custom Rest client whenever you need to, e.g.:

private RestTemplate restTemplate;


This assumes your trying to connect to a Rest endpoint, but you can also use the above HttpClient bean for whatever you want.

IF... OR IF... in a windows batch file

Never got exist to work.

I use if not exist g:xyz/what goto h: Else xcopy c:current/files g:bu/current There are modifiers /a etc. Not sure which ones. Laptop in shop. And computer in office. I am not there.

Never got batch files to work above Windows XP

Where can I download IntelliJ IDEA Color Schemes?

Please note there are two very nice color schemes by default in IDEA 10.

The one that is included is named Railcasts. It is included with the Ruby plugin (free official plugin, install via plugin manager).

Railcasts IDEA 10 color scheme

ASP.NET MVC5/IIS Express unable to debug - Code Not Running

I made it work by doing the following:

  • Delete the ".vs" folder under the application folder
  • Delete the "IISExpress" folder from the Document
  • Enable the 64 bit version of IIS Express on visual studio by going to Tools -> Options -> Projects and Solutions -> Web Projects enter image description here
  • May need to delete everything from temp folder
  • May need to change the port by right click on project, go to properties, under web and change the project url port.

How to Use slideDown (or show) function on a table row?

I liked the plugin that Vinny's written and have been using. But in case of tables inside sliding row (tr/td), the rows of nested table are always hidden even after slid up. So I did a quick and simple hack in the plugin not to hide the rows of nested table. Just change the following line

var $cells = $(this).find('td');


var $cells = $(this).find('> td');

which finds only immediate tds not nested ones. Hope this helps someone using the plugin and have nested tables.

get next sequence value from database using hibernate

Here is what worked for me (specific to Oracle, but using scalar seems to be the key)

Long getNext() {
    Query query = 
        session.createSQLQuery("select MYSEQ.nextval as num from dual")
            .addScalar("num", StandardBasicTypes.BIG_INTEGER);

    return ((BigInteger) query.uniqueResult()).longValue();

Thanks to the posters here: springsource_forum

Update statement using with clause

The WITH syntax appears to be valid in an inline view, e.g.

UPDATE (WITH comp AS ...
        SELECT SomeColumn, ComputedValue FROM t INNER JOIN comp ...)
   SET SomeColumn=ComputedValue;

But in the quick tests I did this always failed with ORA-01732: data manipulation operation not legal on this view, although it succeeded if I rewrote to eliminate the WITH clause. So the refactoring may interfere with Oracle's ability to guarantee key-preservation.

You should be able to use a MERGE, though. Using the simple example you've posted this doesn't even require a WITH clause:

MERGE INTO mytable t
USING (select *, 42 as ComputedValue from mytable where id = 1) comp
ON ( =

But I understand you have a more complex subquery you want to factor out. I think that you will be able to make the subquery in the USING clause arbitrarily complex, incorporating multiple WITH clauses.

How to get/generate the create statement for an existing hive table?

As of Hive 0.10 this patch-967 implements SHOW CREATE TABLE which "shows the CREATE TABLE statement that creates a given table, or the CREATE VIEW statement that creates a given view."



Why should hash functions use a prime number modulus?

I'd like to add something for Steve Jessop's answer(I can't comment on it since I don't have enough reputation). But I found some helpful material. His answer is very help but he made a mistake: the bucket size should not be a power of 2. I'll just quote from the book "Introduction to Algorithm" by Thomas Cormen, Charles Leisersen, et al on page263:

When using the division method, we usually avoid certain values of m. For example, m should not be a power of 2, since if m = 2^p, then h(k) is just the p lowest-order bits of k. Unless we know that all low-order p-bit patterns are equally likely, we are better off designing the hash function to depend on all the bits of the key. As Exercise 11.3-3 asks you to show, choosing m = 2^p-1 when k is a character string interpreted in radix 2^p may be a poor choice, because permuting the characters of k does not change its hash value.

Hope it helps.

How to hide element label by element id in CSS?

You have to give a separate id to the label too.

<label for="foo" id="foo_label">text</label>

#foo_label {display: none;}

Or hide the whole row

<tr id="foo_row">/***/</tr>

#foo_row {display: none;}

How to delete columns in a CSV file?

Off the top of my head, this will do it without any sort of error checking nor ability to configure anything. That is "left to the reader".

outFile = open( 'newFile', 'w' )
for line in open( 'oldFile' ):
   items = line.split( ',' )
   outFile.write( ','.join( items[:2] + items[ 3: ] ) )

Javascript set img src

If you're using WinJS you can change the src through the Utilities functions."pic1").setAttribute("src", searchPic.src);

Error :Request header field Content-Type is not allowed by Access-Control-Allow-Headers

It is most likely due to a cross-origin request, but it may not be. For me, I had been debugging an API and had set the Access-Control-Allow-Origin to *, but it appears that recent versions of Chrome are requiring an extra header. Try prepending the following to your file if you are using PHP:

header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept");

Make sure that you haven't already used header in another file, or you will get a nasty error. See the docs for more.

Detect if a browser in a mobile device (iOS/Android phone/tablet) is used

Update (June 2016): I now try to support touch and mouse input on every resolution, since the device landscape is slowly blurring the lines between what things are and aren't touch devices. iPad Pros are touch-only with the resolution of a 13" laptop. Windows laptops now frequently come with touch screens.

Other similar SO answers (see other answer on this question) might have different ways to try to figure out what sort of device the user is using, but none of them are fool-proof. I encourage you to check those answers out if you absolutely need to try to determine the device.

iPhones, for one, ignore the handheld query (Source). And I wouldn't be surprised if other smartphones do, too, for similar reasons.

The current best way that I use to detect a mobile device is to know its width and use the corresponding media query to catch it. That link there lists some popular ones. A quick Google search would yield you any others you might need, I'm sure.

For more iPhone-specific ones (such as Retina display), check out that first link I posted.

How to format a float in javascript?

The key here I guess is to round up correctly first, then you can convert it to String.

function roundOf(n, p) {
    const n1 = n * Math.pow(10, p + 1);
    const n2 = Math.floor(n1 / 10);
    if (n1 >= (n2 * 10 + 5)) {
        return (n2 + 1) / Math.pow(10, p);
    return n2 / Math.pow(10, p);

// All edge cases listed in this thread
roundOf(95.345, 2); // 95.35
roundOf(95.344, 2); // 95.34
roundOf(5.0364342423, 2); // 5.04
roundOf(0.595, 2); // 0.60
roundOf(0.335, 2); // 0.34
roundOf(0.345, 2); // 0.35
roundOf(551.175, 2); // 551.18
roundOf(0.3445434, 2); // 0.34

Now you can safely format this value with toFixed(p). So with your specific case:

roundOf(0.3445434, 2).toFixed(2); // 0.34

How to disable <br> tags inside <div> by css?

<p style="color:black">Shop our collection of beautiful women's <br> <span> wedding ring in classic &amp; modern design.</span></p>

Remove <br> effect using CSS.

<style> p br{ display:none; } </style>

How to properly use unit-testing's assertRaises() with NoneType objects?

Complete snippet would look like the following. It expands @mouad's answer to asserting on error's message (or generally str representation of its args), which may be useful.

from unittest import TestCase

class TestNoneTypeError(TestCase):

  def setUp(self): 
    self.testListNone = None

  def testListSlicing(self):
    with self.assertRaises(TypeError) as ctx:
    self.assertEqual("'NoneType' object is not subscriptable", str(ctx.exception))

How can I measure the actual memory usage of an application or process?

  • Last but not least use htop.
$ sudo apt-get update
$ sudo apt-get install htop
  • Run htop using below command.
$ htop
  • Note for newcomers: dollar symbol is used to show we are running command on a terminal

How to get element by innerText

You can use jQuery :contains() Selector

var element = $( "a:contains('SearchingText')" );

How do I find my host and username on mysql?

You should be able to access the local database by using the name localhost. There is also a way to determine the hostname of the computer you're running on, but it doesn't sound like you need that. As for the username, you can either (1) give permissions to the account that PHP runs under to access the database without a password, or (2) store the username and password that you need to connect with (hard-coded or stored in a config file), and pass those as arguments to mysql_connect. See

How to edit my Excel dropdown list?

Attribute_Brands is a named range.

On any worksheet (tab) press F5 and type Attribute_Brands into the reference box and click on the OK button.

This will take you to the named range.

The data in it can be updated by typing new values into the cells.

The named range can be altered via the 'Insert - Name - Define' menu.

Difference between drop table and truncate table?

Drop drop whole table and all its structure

truncate delete all rows from table it is different from delete that it also delete indexes of rows

How to terminate a process in vbscript

The Win32_Process class provides access to both 32-bit and 64-bit processes when the script is run from a 64-bit command shell.

If this is not an option for you, you can try using the taskkill command:

Dim oShell : Set oShell = CreateObject("WScript.Shell")

' Launch notepad '
oShell.Run "notepad"
WScript.Sleep 3000

' Kill notepad '
oShell.Run "taskkill /im notepad.exe", , True

A quick and easy way to join array elements with a separator (the opposite of split) in Java

This options is fast and clear:

  public static String join(String separator, String... values) {
    StringBuilder sb = new StringBuilder(128);
    int end = 0;
    for (String s : values) {
      if (s != null) {
        end = sb.length();
    return sb.substring(0, end);

How to screenshot website in JavaScript client-side / how Google did it? (no need to access HDD)

I needed to snapshot a div on the page (for a webapp I wrote) that is protected by JWT's and makes very heavy use of Angular.

I had no luck with any of the above methods.

I ended up taking the outerHTML of the div I needed, cleaning it up a little (*) and then sending it to the server where I run wkhtmltopdf against it.

This is working very well for me.

(*) various input devices in my pages didn't render as checked or have their text values when viewed in the pdf... So I run a little bit of jQuery on the html before I send it up for rendering. ex: for text input items -- I copy their .val()'s into 'value' attributes, which then can be seen by wkhtmlpdf

How to add elements of a string array to a string array list?

Use asList() method. From java Doc asList

List<String> species = Arrays.asList(speciesArr);

How to get index of object by its property in JavaScript?

Extended Chris Pickett's answer because in my case I needed to search deeper than one attribute level:

function findWithAttr(array, attr, value) {
  if (attr.indexOf('.') >= 0) {
    var split = attr.split('.');
    var attr1 = split[0];
    var attr2 = split[1];
    for(var i = 0; i < array.length; i += 1) {
      if(array[i][attr1][attr2] === value) {
        return i;
  } else {
    for(var i = 0; i < array.length; i += 1) {
      if(array[i][attr] === value) {
        return i;

You can pass 'attr1.attr2' into the function

No Persistence provider for EntityManager named

Try also copying the persistence.xml manually to the folder <project root>\bin\META-INF. This fixed the problem in Eclipse Neon with EclipseLink 2.5.2 using a simple plug-in project.

Applying Comic Sans Ms font style

The httpd dæmon on OpenBSD uses the following stylesheet for all of its error messages, which presumably covers all the Comic Sans variations on non-Windows systems:

810    style = "body { background-color: white; color: black; font-family: "
811        "'Comic Sans MS', 'Chalkboard SE', 'Comic Neue', sans-serif; }\n"
812        "hr { border: 0; border-bottom: 1px dashed; }\n";

E.g., try this:

font-family: 'Comic Sans MS', 'Chalkboard SE', 'Comic Neue', sans-serif;

Font is not available to the JVM with Jasper Reports

Try adding the line


to your file.

Jasper stops finding one font

What are the differences between a HashMap and a Hashtable in Java?

HashMap: An implementation of the Map interface that uses hash codes to index an array. Hashtable: Hi, 1998 called. They want their collections API back.

Seriously though, you're better off staying away from Hashtable altogether. For single-threaded apps, you don't need the extra overhead of synchronisation. For highly concurrent apps, the paranoid synchronisation might lead to starvation, deadlocks, or unnecessary garbage collection pauses. Like Tim Howland pointed out, you might use ConcurrentHashMap instead.

How to change navigation bar color in iOS 7 or 6?

Try the code below in the - (void)viewDidLoad of your ViewController.m

[[[self navigationController] navigationBar] setTintColor:[UIColor yellowColor]];

this did work for me in iOS 6.. Try it..

Jquery insert new row into table at a certain index

I know it's coming late but for those people who want to implement it purely using the JavaScript , here's how you can do it:

  1. Get the reference to the current tr which is clicked.
  2. Make a new tr DOM element.
  3. Add it to the referred tr parent node.


                        <button id="0" onclick="addRow()">Expand</button>

                        <button id="1" onclick="addRow()">Expand</button>
                        <button id="2" onclick="addRow()">Expand</button>

In JavaScript:

function addRow() {
        var evt =;
        var btn_clicked = document.getElementById(evt);
        var tr_referred = btn_clicked.parentNode.parentNode;
        var td = document.createElement('td');
        td.innerHTML = 'abc';
        var tr = document.createElement('tr');
        tr_referred.parentNode.insertBefore(tr, tr_referred.nextSibling);
        return tr;

This will add the new table row exactly below the row on which the button is clicked.

MySQL dump by query

This should work

mysqldump --databases X --tables Y --where="1 limit 1000000"

How to run sql script using SQL Server Management Studio?

This website has a concise tutorial on how to use SQL Server Management Studio. As you will see you can open a "Query Window", paste your script and run it. It does not allow you to execute scripts by using the file path. However, you can do this easily by using the command line (cmd.exe):

sqlcmd -S .\SQLExpress -i SqlScript.sql

Where SqlScript.sql is the script file name located at the current directory. See this Microsoft page for more examples

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

Python 3.6 - __init_subclass__

As other answer mentioned you can check the __subclasses__ attribute to get the list of subclasses, since python 3.6 you can modify this attribute creation by overriding the __init_subclass__ method.

class PluginBase:
    subclasses = []

    def __init_subclass__(cls, **kwargs):

class Plugin1(PluginBase):

class Plugin2(PluginBase):

This way, if you know what you're doing, you can override the behavior of of __subclasses__ and omit/add subclasses from this list.

How to serialize Joda DateTime with Jackson JSON processor?

I'm using Java 8 and this worked for me.

Add the dependency on pom.xml


and add JodaModule on your ObjectMapper

ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JodaModule());

Rest-assured. Is it possible to extract value from request json?

I found the answer :)

Use JsonPath or XmlPath (in case you have XML) to get data from the response body.

In my case:

JsonPath jsonPath = new JsonPath(responseBody);
int user_id = jsonPath.getInt("user_id");

In Python, how do I loop through the dictionary and change the value if it equals something?

You could create a dict comprehension of just the elements whose values are None, and then update back into the original:

tmp = dict((k,"") for k,v in mydict.iteritems() if v is None)

Update - did some performance tests

Well, after trying dicts of from 100 to 10,000 items, with varying percentage of None values, the performance of Alex's solution is across-the-board about twice as fast as this solution.

Rename multiple files in cmd

I was puzzled by this also... didn't like the parentheses that windows puts in when you rename in bulk. In my research I decided to write a script with PowerShell instead. Super easy and worked like a charm. Now I can use it whenever I need to batch process file renaming... which is frequent. I take hundreds of photos and the camera names them IMG1234.JPG etc...

Here is the script I wrote:

# filename: bulk_file_rename.ps1
# by: subcan
# PowerShell script to rename multiple files within a folder to a 
# name that increments without (#)
# create counter
$int = 1
# ask user for what they want
$regex = Read-Host "Regex for files you are looking for? ex. IMG*.JPG "
$file_name = Read-Host "What is new file name, without extension? ex. New Image "
$extension = Read-Host "What extension do you want? ex. .JPG "
# get a total count of the files that meet regex
$total = Get-ChildItem -Filter $regex | measure
# while loop to rename all files with new name
while ($int -le $total.Count)
    # diplay where in loop you are
    Write-Host "within while loop" $int  
    # create variable for concatinated new name - 
    # $int.ToString(000) ensures 3 digit number 001, 010, etc
    $new_name = $file_name + $int.ToString(000)+$extension
    # get the first occurance and rename
    Get-ChildItem -Filter $regex | select -First 1 | Rename-Item -NewName $new_name
    # display renamed file name
    Write-Host "Renamed to" $new_name
    # increment counter

I hope that this is helpful to someone out there.


Access blocked by CORS policy: Response to preflight request doesn't pass access control check

CORS headers should be sent from the server. If you use PHP it will be like this:

header('Access-Control-Allow-Origin: your-host');
header('Access-Control-Allow-Credentials: true');
header('Access-Control-Allow-Methods: your-methods like POST,GET');
header('Access-Control-Allow-Headers: content-type or other');
header('Content-Type: application/json');

How to print the values of slices

I wrote a package named Pretty Slice. You can use it to visualize slices, and their backing arrays, etc.

package main

import pretty ""

func main() {
    nums := []int{1, 9, 5, 6, 4, 8}
    odds := nums[:3]
    evens := nums[3:]

    nums[1], nums[3] = 9, 6
    pretty.Show("nums", nums)
    pretty.Show("odds : nums[:3]", odds)
    pretty.Show("evens: nums[3:]", evens)

This code is going produce and output like this one:

enter image description here

For more details, please read:

Using Java with Nvidia GPUs (CUDA)

First of all, you should be aware of the fact that CUDA will not automagically make computations faster. On the one hand, because GPU programming is an art, and it can be very, very challenging to get it right. On the other hand, because GPUs are well-suited only for certain kinds of computations.

This may sound confusing, because you can basically compute anything on the GPU. The key point is, of course, whether you will achieve a good speedup or not. The most important classification here is whether a problem is task parallel or data parallel. The first one refers, roughly speaking, to problems where several threads are working on their own tasks, more or less independently. The second one refers to problems where many threads are all doing the same - but on different parts of the data.

The latter is the kind of problem that GPUs are good at: They have many cores, and all the cores do the same, but operate on different parts of the input data.

You mentioned that you have "simple math but with huge amount of data". Although this may sound like a perfectly data-parallel problem and thus like it was well-suited for a GPU, there is another aspect to consider: GPUs are ridiculously fast in terms of theoretical computational power (FLOPS, Floating Point Operations Per Second). But they are often throttled down by the memory bandwidth.

This leads to another classification of problems. Namely whether problems are memory bound or compute bound.

The first one refers to problems where the number of instructions that are done for each data element is low. For example, consider a parallel vector addition: You'll have to read two data elements, then perform a single addition, and then write the sum into the result vector. You will not see a speedup when doing this on the GPU, because the single addition does not compensate for the efforts of reading/writing the memory.

The second term, "compute bound", refers to problems where the number of instructions is high compared to the number of memory reads/writes. For example, consider a matrix multiplication: The number of instructions will be O(n^3) when n is the size of the matrix. In this case, one can expect that the GPU will outperform a CPU at a certain matrix size. Another example could be when many complex trigonometric computations (sine/cosine etc) are performed on "few" data elements.

As a rule of thumb: You can assume that reading/writing one data element from the "main" GPU memory has a latency of about 500 instructions....

Therefore, another key point for the performance of GPUs is data locality: If you have to read or write data (and in most cases, you will have to ;-)), then you should make sure that the data is kept as close as possible to the GPU cores. GPUs thus have certain memory areas (referred to as "local memory" or "shared memory") that usually is only a few KB in size, but particularly efficient for data that is about to be involved in a computation.

So to emphasize this again: GPU programming is an art, that is only remotely related to parallel programming on the CPU. Things like Threads in Java, with all the concurrency infrastructure like ThreadPoolExecutors, ForkJoinPools etc. might give the impression that you just have to split your work somehow and distribute it among several processors. On the GPU, you may encounter challenges on a much lower level: Occupancy, register pressure, shared memory pressure, memory coalescing ... just to name a few.

However, when you have a data-parallel, compute-bound problem to solve, the GPU is the way to go.

A general remark: Your specifically asked for CUDA. But I'd strongly recommend you to also have a look at OpenCL. It has several advantages. First of all, it's an vendor-independent, open industry standard, and there are implementations of OpenCL by AMD, Apple, Intel and NVIDIA. Additionally, there is a much broader support for OpenCL in the Java world. The only case where I'd rather settle for CUDA is when you want to use the CUDA runtime libraries, like CUFFT for FFT or CUBLAS for BLAS (Matrix/Vector operations). Although there are approaches for providing similar libraries for OpenCL, they can not directly be used from Java side, unless you create your own JNI bindings for these libraries.

You might also find it interesting to hear that in October 2012, the OpenJDK HotSpot group started the project "Sumatra": . The goal of this project is to provide GPU support directly in the JVM, with support from the JIT. The current status and first results can be seen in their mailing list at

However, a while ago, I collected some resources related to "Java on the GPU" in general. I'll summarize these again here, in no particular order.

(Disclaimer: I'm the author of and )

(Byte)code translation and OpenCL code generation: : An open-source library that is created and actively maintained by AMD. In a special "Kernel" class, one can override a specific method which should be executed in parallel. The byte code of this method is loaded at runtime using an own bytecode reader. The code is translated into OpenCL code, which is then compiled using the OpenCL compiler. The result can then be executed on the OpenCL device, which may be a GPU or a CPU. If the compilation into OpenCL is not possible (or no OpenCL is available), the code will still be executed in parallel, using a Thread Pool. : An open-source library for converting parts of Java into CUDA programs. It offers dedicated interfaces that may be implemented to indicate that a certain class should be executed on the GPU. In contrast to Aparapi, it tries to automatically serialize the "relevant" data (that is, the complete relevant part of the object graph!) into a representation that is suitable for the GPU. : A library for translating annotated Java code (with some limitations) into CUDA code, which is then compiled into a library that executes the code on the GPU. The Library was developed in the context of a PhD thesis, which contains profound background information about the translation process. : Scala bindings for OpenCL. Allows special Scala collections to be processed in parallel with OpenCL. The functions that are called on the elements of the collections can be usual Scala functions (with some limitations) which are then translated into OpenCL kernels.

Language extensions : A language extension for Java that allows parallel constructs (e.g. parallel for loops, OpenMP style) which are then executed on the GPU with OpenCL. Unfortunately, this very promising project is no longer maintained. (JCUDA) : A library that can translate special Java Code (called JCUDA code) into Java- and CUDA-C code, which can then be compiled and executed on the GPU. However, the library does not seem to be publicly available. : Java language extension for for OpenMP constructs, with a CUDA backend

Java OpenCL/CUDA binding libraries : Java bindings for OpenCL: An object-oriented OpenCL library, based on auto-generated low-level bindings : Java bindings for OpenCL: An object-oriented OpenCL library, based on auto-generated low-level bindings : Java bindings for OpenCL: Auto-generated low-level bindings and object-oriented convenience classes : Java bindings for OpenCL: Low-level bindings that are a 1:1 mapping of the original OpenCL API : Java bindings for CUDA: Low-level bindings that are a 1:1 mapping of the original CUDA API

Miscellaneous : Java bindings for OpenCL. Seem to be no longer maintained since 2010 : Java bindings for CUDA. Seem to be no longer maintained

How to write and save html file in python?

shorter version of Nurul Akter Towhid's answer (the fp.close is automated):

with open("my.html","w") as fp:

Convert a float64 to an int in Go

If its simply from float64 to int, this should work

package main

import (

func main() {
    nf := []float64{-1.9999, -2.0001, -2.0, 0, 1.9999, 2.0001, 2.0}

    fmt.Printf("Round : ")
    for _, f := range nf {
        fmt.Printf("%d ", round(f))

    //rounddown ie. math.floor
    fmt.Printf("RoundD: ")
    for _, f := range nf {
        fmt.Printf("%d ", roundD(f))

    //roundup ie. math.ceil
    fmt.Printf("RoundU: ")
    for _, f := range nf {
        fmt.Printf("%d ", roundU(f)) 


func roundU(val float64) int {
    if val > 0 { return int(val+1.0) }
    return int(val)

func roundD(val float64) int {
    if val < 0 { return int(val-1.0) }
    return int(val)

func round(val float64) int {
    if val < 0 { return int(val-0.5) }
    return int(val+0.5)


Round : -2 -2 -2 0 2 2 2 
RoundD: -2 -3 -3 0 1 2 2 
RoundU: -1 -2 -2 0 2 3 3 

Here's the code in the playground -

How to read a file without newlines?

temp = open(filename,'r').read().split('\n')

Convert RGBA PNG to RGB with PIL

The transparent parts mostly have RGBA value (0,0,0,0). Since the JPG has no transparency, the jpeg value is set to (0,0,0), which is black.

Around the circular icon, there are pixels with nonzero RGB values where A = 0. So they look transparent in the PNG, but funny-colored in the JPG.

You can set all pixels where A == 0 to have R = G = B = 255 using numpy like this:

import Image
import numpy as np

FNAME = 'logo.png'
img ='RGBA')
x = np.array(img)
r, g, b, a = np.rollaxis(x, axis = -1)
r[a == 0] = 255
g[a == 0] = 255
b[a == 0] = 255
x = np.dstack([r, g, b, a])
img = Image.fromarray(x, 'RGBA')'/tmp/out.jpg')

enter image description here

Note that the logo also has some semi-transparent pixels used to smooth the edges around the words and icon. Saving to jpeg ignores the semi-transparency, making the resultant jpeg look quite jagged.

A better quality result could be made using imagemagick's convert command:

convert logo.png -background white -flatten /tmp/out.jpg

enter image description here

To make a nicer quality blend using numpy, you could use alpha compositing:

import Image
import numpy as np

def alpha_composite(src, dst):
    Return the alpha composite of src and dst.

    src -- PIL RGBA Image object
    dst -- PIL RGBA Image object

    The algorithm comes from
    src = np.asarray(src)
    dst = np.asarray(dst)
    out = np.empty(src.shape, dtype = 'float')
    alpha = np.index_exp[:, :, 3:]
    rgb = np.index_exp[:, :, :3]
    src_a = src[alpha]/255.0
    dst_a = dst[alpha]/255.0
    out[alpha] = src_a+dst_a*(1-src_a)
    old_setting = np.seterr(invalid = 'ignore')
    out[rgb] = (src[rgb]*src_a + dst[rgb]*dst_a*(1-src_a))/out[alpha]
    out[alpha] *= 255
    # astype('uint8') maps np.nan (and np.inf) to 0
    out = out.astype('uint8')
    out = Image.fromarray(out, 'RGBA')
    return out            

FNAME = 'logo.png'
img ='RGBA')
white ='RGBA', size = img.size, color = (255, 255, 255, 255))
img = alpha_composite(img, white)'/tmp/out.jpg')

enter image description here

What is a practical use for a closure in JavaScript?

Use of Closures:

Closures are one of the most powerful features of JavaScript. JavaScript allows for the nesting of functions and grants the inner function full access to all the variables and functions defined inside the outer function (and all other variables and functions that the outer function has access to). However, the outer function does not have access to the variables and functions defined inside the inner function.

This provides a sort of security for the variables of the inner function. Also, since the inner function has access to the scope of the outer function, the variables and functions defined in the outer function will live longer than the outer function itself, if the inner function manages to survive beyond the life of the outer function. A closure is created when the inner function is somehow made available to any scope outside the outer function.


var createPet = function(name) {
  var sex;
  return {
    setName: function(newName) {
      name = newName;
    getName: function() {
      return name;
    getSex: function() {
      return sex;
    setSex: function(newSex) {
      if(typeof newSex == "string" && (newSex.toLowerCase() == "male" || newSex.toLowerCase() == "female")) {
        sex = newSex;

var pet = createPet("Vivie");
console.log(pet.getName());                  // Vivie

console.log(pet.getSex());                   // male
console.log(pet.getName());                  // Oliver

In the code above, the name variable of the outer function is accessible to the inner functions, and there is no other way to access the inner variables except through the inner functions. The inner variables of the inner function act as safe stores for the inner functions. They hold "persistent", yet secure, data for the inner functions to work with. The functions do not even have to be assigned to a variable, or have a name. read here for detail.

How to change indentation in Visual Studio Code?

In my case "EditorConfig for VS Code" extention is overriding VSCode settings. If you have it installed, then check .editorconfig file in the root folder of the project.

Here is an example config. The "indent_size" sets the number of spaces for a tab.

root = true

indent_style = space
indent_size = 4
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

trim_trailing_whitespace = false

Map a network drive to be used by a service

You wan't to either change the user that the Service runs under from "System" or find a sneaky way to run your mapping as System.

The funny thing is that this is possible by using the "at" command, simply schedule your drive mapping one minute into the future and it will be run under the System account making the drive visible to your service.

Hibernate - Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1

Few ways I debugged this error:

  1. As suggested in the accepted answer- turn on show sql.
  2. I found there is some issue with setting up the id in the hibernate sql.
  3. Found that I was missing @GeneratedValue(strategy=GenerationType.IDENTITY)

How to get the exact local time of client?

Try on this way

    function timenow(){
    var now= new Date(), 
    ampm= 'am', 
    h= now.getHours(), 
    m= now.getMinutes(), 
    s= now.getSeconds();
    if(h>= 12){
        if(h>12) h -= 12;
        ampm= 'pm';

    if(m<10) m= '0'+m;
    if(s<10) s= '0'+s;
    return now.toLocaleDateString()+ ' ' + h + ':' + m + ':' + s + ' ' + ampm;


is a function to change the date time format like toLocaleDateString("en-us")

How do I protect javascript files?

As I said in the comment I left on gion_13 answer before (please read), you really can't. Not with javascript.

If you don't want the code to be available client-side (= stealable without great efforts), my suggestion would be to make use of PHP (ASP,Python,Perl,Ruby,JSP + Java-Servlets) that is processed server-side and only the results of the computation/code execution are served to the user. Or, if you prefer, even Flash or a Java-Applet that let client-side computation/code execution but are compiled and thus harder to reverse-engine (not impossible thus).

Just my 2 cents.

HTML.HiddenFor value set

You shouldn't need to set the value in the attributes parameter. MVC should automatically bind it for you.

@Html.HiddenFor(model => model.title, new { id= "natureOfVisitField" })

Login failed for user 'DOMAIN\MACHINENAME$'

This error occurs when you have configured your application with IIS, and IIS goes to SQL Server and tries to login with credentials that do not have proper permissions. This error can also occur when replication or mirroring is set up. I will be going over a solution that works always and is very simple. Go to SQL Server >> Security >> Logins and right click on NT AUTHORITY\NETWORK SERVICE and select Properties

In newly opened screen of Login Properties, go to the “User Mapping” tab. Then, on the “User Mapping” tab, select the desired database – especially the database for which this error message is displayed. On the lower screen, check the role db_owner. Click OK.

log4j: Log output of a specific class to a specific appender

An example:

log4j.rootLogger=ERROR, logfile

log4j.appender.logfile.layout.ConversionPattern=%-6r %d{ISO8601} %-5p %40.40c %x - %m\n, myappender

log4j.appender.myappender.layout.ConversionPattern=%-6r %d{ISO8601} %-5p %40.40c %x - %m\n

iOS 11, 12, and 13 installed certificates not trusted automatically (self signed)

This has happened to me also, after undating to IOS11 on my iPhone. When I try to connect to the corporate network it bring up the corporate cert and says it isn't trusted. I press the 'trust' button and the connection fails and the cert does not appear in the trusted certs list.

Is there a Visual Basic 6 decompiler?

This link provides a lot of resources for VB6 Decompiling, but it seems like it will depend greatly on what you DO have (do you still have the pre-link Object code [EDIT: er... p-code I mean], or just the EXE?) Either way, it looks like there's something, take a look in there.

Create an empty list in python with certain size

One simple way to create a 2D matrix of size n using nested list comprehensions:

m = [[None for _ in range(n)] for _ in range(n)]

Installing Git on Eclipse

It's Very Easy To Install By Following Below Steps In Eclipse JUNO version

Help-->Eclipse Marketplace-->Find: beside Textbox u can type "Egit"-->select Egit-git team provider intall button-->follow next steps and finally click finish

Sending JSON to PHP using ajax

If you want to get the values via the $_POST variable then you should not specify the contentType as "application/json" but rather use the default "application/x-www-form-urlencoded; charset=UTF-8":


var person = { name: "John" };

    //contentType: "application/json", // php://input
    contentType: "application/x-www-form-urlencoded; charset=UTF-8", // $_POST
    dataType : "json",
    method: "POST",
    url: "http://localhost/test/test.php",
    data: {data: person}
.done(function(data) {  
    console.log("test: ", data);
.fail(function(data) {
    console.log("error: ", data);



// $_POST

$jsonString = $_POST['data'];

$newJsonString = json_encode($jsonString);
header('Content-Type: application/json');
echo $newJsonString;

Else if you want to send a JSON from JavaScript to PHP:


var person = { name: "John" };

    contentType: "application/json", // php://input
    //contentType: "application/x-www-form-urlencoded; charset=UTF-8", // $_POST
    dataType : "json",
    method: "POST",
    url: "http://localhost/test/test.php",
    data: person
.done(function(data) {  
    console.log("test: ", data);
.fail(function(data) {
    console.log("error: ", data);



$jsonString = file_get_contents("php://input");
$phpObject = json_decode($jsonString);

$newJsonString = json_encode($phpObject);
header('Content-Type: application/json');
echo $newJsonString;

Run-time error '3061'. Too few parameters. Expected 1. (Access 2007)

In My case I had an INSERT INTO TableA (_ ,_ ,_) SELECT _ ,_ ,_ from TableB, a run-time error of 33061 was a field error. As @david mentioned. Either it was a field error: what I wrote in SQL statement as a column name did not match the column names in the actual access tables, for TableA or TableB.

I also have an error like @DATS but it was a run-time error 3464.

Delete cookie by name?

In order to delete a cookie set the expires date to something in the past. A function that does this would be.

var delete_cookie = function(name) {
    document.cookie = name + '=;expires=Thu, 01 Jan 1970 00:00:01 GMT;';

Then to delete a cookie named roundcube_sessauth just do.


Android: How to set password property in an edit text?

To set password enabled in EditText, We will have to set an "inputType" attribute in xml file.If we are using only EditText then we will have set input type in EditText as given in below code.

                    android:layout_height="match_parent" />

Password enable attribute is


But if we are implementing Password EditText with Material Design (With Design support library) then we will have write code as given bellow.


                    android:layout_height="match_parent" />

@Note: - In Android SDK 24 and above, "passwordToggleEnabled" is by default true. So if we have the customs handling of show/hide feature in the password EditText then we will have to set it false in code as given above in .


To add above line, we will have to add below line in root layout.


What's the algorithm to calculate aspect ratio?

bit of a strange way to do this but use the resolution as the aspect. E.G.


or you can try

var w = screen.width;
var h = screen.height;
for(var i=1,asp=w/h;i<5000;i++){
  if(asp*i % 1==0){

Running sites on "localhost" is extremely slow

I had the same problem with PHP. I solved it by changing "localhost" to "" in database connection parameters like someone suggested here: . I think it may work for you too, give it a try.

how to start stop tomcat server using CMD?

Change directory to tomcat/bin directory in cmd prompt

cd C:\Program Files\Apache Software Foundation\Tomcat 8.0\bin

Run the below command to start:

On Linux: >

On Windows: >startup.bat

Run these commands to stop

On Linux:

On Windows: shutdown.bat

Remove rows not .isin('X')

You can use numpy.logical_not to invert the boolean array returned by isin:

In [63]: s = pd.Series(np.arange(10.0))

In [64]: x = range(4, 8)

In [65]: mask = np.logical_not(s.isin(x))

In [66]: s[mask]
0    0
1    1
2    2
3    3
8    8
9    9

As given in the comment by Wes McKinney you can also use


Can I concatenate multiple MySQL rows into one field?

Try this:

DECLARE @Hobbies NVARCHAR(200) = ' '

SELECT @Hobbies = @Hobbies + hobbies + ',' FROM peoples_hobbies WHERE person_id = 5;


set @sql='';
set @result='';
set @separator=' union \r\n';
@sql:=concat('select ''',INFORMATION_SCHEMA.COLUMNS.COLUMN_NAME  ,''' as col_name,',
' FROM ',
) as sql_piece, if(@result:=if(@result='',@sql,concat(@result,@separator,@sql)),'','') as dummy
select @result;

Laravel Eloquent where field is X or null

Using coalesce() converts null to 0:

$query = Model::where('field1', 1)
    ->where(DB::raw('COALESCE(datefield_at,0)'), '<', $date)

How to calculate Date difference in Hive

datediff(to_date(String timestamp), to_date(String timestamp))

For example:

SELECT datediff(to_date('2019-08-03'), to_date('2019-08-01')) <= 2;

how do you insert null values into sql server


How to get "their" changes in the middle of conflicting Git rebase?

You want to use:

git checkout --ours foo/
git add foo/

If you rebase a branch feature_x against main (i.e. running git rebase main while on branch feature_x), during rebasing ours refers to main and theirs to feature_x.

As pointed out in the git-rebase docs:

Note that a rebase merge works by replaying each commit from the working branch on top of the branch. Because of this, when a merge conflict happens, the side reported as ours is the so-far rebased series, starting with <upstream>, and theirs is the working branch. In other words, the sides are swapped.

For further details read this thread.

C# An established connection was aborted by the software in your host machine

This problem appear if two software use same port for connecting to the server
try to close the port by cmd according to your operating system
then reboot your Android studio or your Eclipse or your Software.

How do I revert to a previous package in Anaconda?

For the case that you wish to revert a recently installed package that made several changes to dependencies (such as tensorflow), you can "roll back" to an earlier installation state via the following method:

conda list --revisions
conda install --revision [revision number]

The first command shows previous installation revisions (with dependencies) and the second reverts to whichever revision number you specify.

Note that if you wish to (re)install a later revision, you may have to sequentially reinstall all intermediate versions. If you had been at revision 23, reinstalled revision 20 and wish to return, you may have to run each:

conda install --revision 21
conda install --revision 22
conda install --revision 23

How to use S_ISREG() and S_ISDIR() POSIX Macros?

You're using S_ISREG() and S_ISDIR() correctly, you're just using them on the wrong thing.

In your while((dit = readdir(dip)) != NULL) loop in main, you're calling stat on currentPath over and over again without changing currentPath:

if(stat(currentPath, &statbuf) == -1) {
    return errno;

Shouldn't you be appending a slash and dit->d_name to currentPath to get the full path to the file that you want to stat? Methinks that similar changes to your other stat calls are also needed.

Find the PID of a process that uses a port on Windows

PowerShell (Core-compatible) one-liner to ease copypaste scenarios:

netstat -aon | Select-String 8080 | ForEach-Object { $_ -replace '\s+', ',' } | ConvertFrom-Csv -Header @('Empty', 'Protocol', 'AddressLocal', 'AddressForeign', 'State', 'PID') | ForEach-Object { $portProcess = Get-Process | Where-Object Id -eq $_.PID; $_ | Add-Member -NotePropertyName 'ProcessName' -NotePropertyValue $portProcess.ProcessName; Write-Output $_ } | Sort-Object ProcessName, State, Protocol, AddressLocal, AddressForeign | Select-Object  ProcessName, State, Protocol, AddressLocal, AddressForeign | Format-Table


ProcessName State     Protocol AddressLocal AddressForeign
----------- -----     -------- ------------ --------------
System      LISTENING TCP      [::]:8080    [::]:0

Same code, developer-friendly:

$Port = 8080

# Get PID's listening to $Port, as PSObject
$PidsAtPortString = netstat -aon `
  | Select-String $Port
$PidsAtPort = $PidsAtPortString `
  | ForEach-Object { `
      $_ -replace '\s+', ',' `
  } `
  | ConvertFrom-Csv -Header @('Empty', 'Protocol', 'AddressLocal', 'AddressForeign', 'State', 'PID')

# Enrich port's list with ProcessName data
$ProcessesAtPort = $PidsAtPort `
  | ForEach-Object { `
    $portProcess = Get-Process `
      | Where-Object Id -eq $_.PID; `
    $_ | Add-Member -NotePropertyName 'ProcessName' -NotePropertyValue $portProcess.ProcessName; `
    Write-Output $_;

# Show output
$ProcessesAtPort `
  | Sort-Object    ProcessName, State, Protocol, AddressLocal, AddressForeign `
  | Select-Object  ProcessName, State, Protocol, AddressLocal, AddressForeign `
  | Format-Table

Google Chrome redirecting localhost to https

Chrome 63 (out since December 2017), will force all domains ending on .dev (and .foo) to be redirected to HTTPS via a preloaded HTTP Strict Transport Security (HSTS) header. You can find more information about this here.

tr:hover not working

Also try thistr:hover td {color: aqua;} `

Convert list to tuple in Python

Expanding on eumiro's comment, normally tuple(l) will convert a list l into a tuple:

In [1]: l = [4,5,6]

In [2]: tuple
Out[2]: <type 'tuple'>

In [3]: tuple(l)
Out[3]: (4, 5, 6)

However, if you've redefined tuple to be a tuple rather than the type tuple:

In [4]: tuple = tuple(l)

In [5]: tuple
Out[5]: (4, 5, 6)

then you get a TypeError since the tuple itself is not callable:

In [6]: tuple(l)
TypeError: 'tuple' object is not callable

You can recover the original definition for tuple by quitting and restarting your interpreter, or (thanks to @glglgl):

In [6]: del tuple

In [7]: tuple
Out[7]: <type 'tuple'>

Accessing nested JavaScript objects and arrays by string path

// (IE9+) Two steps_x000D_
var pathString = "[0]['property'].others[3].next['final']";_x000D_
var obj = [{_x000D_
  property: {_x000D_
    others: [1, 2, 3, {_x000D_
      next: {_x000D_
        final: "SUCCESS"_x000D_
// Turn string to path array_x000D_
var pathArray = pathString_x000D_
// Add object prototype method_x000D_
Object.prototype.path = function (path) {_x000D_
  try {_x000D_
    return [this].concat(path).reduce(function (f, l) {_x000D_
      return f[l];_x000D_
  } catch (e) {_x000D_
// usage_x000D_

Merge two HTML table cells

Set the colspan attribute to 2.

...but please don't use tables for layout.

Can I delete a git commit but keep the changes?

Using git 2.9 (precisely git reset HEAD^ prompts for more; not sure what is expected input here. Please refer below screenshot

enter image description here

Found other solution git reset HEAD~#numberOfCommits using which we can choose to select number of local commits you want to reset by keeping your changes intact. Hence, we get an opportunity to throw away all local commits as well as limited number of local commits.

Refer below screenshots showing git reset HEAD~1 in action: enter image description here

enter image description here

How to randomize Excel rows

Perhaps the whole column full of random numbers is not the best way to do it, but it seems like probably the most practical as @mariusnn mentioned.

On that note, this stomped me for a while with Office 2010, and while generally answers like the one in lifehacker work,I just wanted to share an extra step required for the numbers to be unique:

  1. Create a new column next to the list that you're going to randomize
  2. Type in =rand() in the first cell of the new column - this will generate a random number between 0 and 1
  3. Fill the column with that formula. The easiest way to do this may be to:

    • go down along the new column up until the last cell that you want to randomize
    • hold down Shift and click on the last cell
    • press Ctrl+D
  4. Now you should have a column of identical numbers, even though they are all generated randomly.

    Random numbers... that are the same...

    The trick here is to recalculate them! Go to the Formulas tab and then click on Calculate Now (or press F9).

    Actually random numbers!

    Now all the numbers in the column will be actually generated randomly.

  5. Go to the Home tab and click on Sort & Filter. Choose whichever order you want (Smallest to Largest or Largest to Smallest) - whichever one will give you a random order with respect to the original order. Then click OK when the Sort Warning prompts you to Expand the selection.

  6. Your list should be randomized now! You can get rid of the column of random numbers if you want.

How to send email by using javascript or jquery

You can do it server-side with nodejs.

Check out the popular Nodemailer package. There are plenty of transports and plugins for integrating with services like AWS SES and SendGrid!

The following example uses SES transport (Amazon SES):

let nodemailer = require("nodemailer");
let aws = require("aws-sdk");
let transporter = nodemailer.createTransport({
  SES: new aws.SES({ apiVersion: "2010-12-01" })

How can I verify a Google authentication API access token?

function authenticate_google_OAuthtoken($user_id)
    $access_token   = google_get_user_token($user_id); // get existing token from DB
    $redirecturl    = $Google_Permissions->redirecturl;
    $client_id      = $Google_Permissions->client_id;
    $client_secret  = $Google_Permissions->client_secret;
    $redirect_uri   = $Google_Permissions->redirect_uri;
    $max_results    = $Google_Permissions->max_results;

    $url = ''.$access_token;
    $response_contacts  =  curl_get_responce_contents($url);
    $response   =   (json_decode($response_contacts));

        return true;
    else if(isset($response->error))
        return false;

How do I make an asynchronous GET request in PHP?

Here's an adaptation of the accepted answer for performing a simple GET request.

One thing to note if the server does any url rewriting, this will not work. You'll need to use a more full featured http client.

   * Performs an async get request (doesn't wait for response)
   * Note: One limitation of this approach is it will not work if server does any URL rewriting
  function async_get($url)

      $fp = fsockopen($parts['host'],
          $errno, $errstr, 30);

      $out = "GET ".$parts['path']." HTTP/1.1\r\n";
      $out.= "Host: ".$parts['host']."\r\n";
      $out.= "Connection: Close\r\n\r\n";
      fwrite($fp, $out);

How to uncheck a checkbox in pure JavaScript?

Recommended, without jQuery:

Give your <input> an ID and refer to that. Also, remove the checked="" part of the <input> tag if you want the checkbox to start out unticked. Then it's:

document.getElementById("my-checkbox").checked = true;

Pure JavaScript, with no Element ID (#1):

var inputs = document.getElementsByTagName('input');

for(var i = 0; i<inputs.length; i++){

  if(typeof inputs[i].getAttribute === 'function' && inputs[i].getAttribute('name') === 'copyNewAddrToBilling'){

    inputs[i].checked = true;



Pure Javascript, with no Element ID (#2):

document.querySelectorAll('.text input[name="copyNewAddrToBilling"]')[0].checked = true;

document.querySelector('.text input[name="copyNewAddrToBilling"]').checked = true;

Note that the querySelectorAll and querySelector methods are supported in these browsers: IE8+, Chrome 4+, Safari 3.1+, Firefox 3.5+ and all mobile browsers.

If the element may be missing, you should test for its existence, e.g.:

var input = document.querySelector('.text input[name="copyNewAddrToBilling"]');
if (!input) { return; }

With jQuery:

$('.text input[name="copyNewAddrToBilling"]').prop('checked', true);

Volatile boolean vs AtomicBoolean

Both are of same concept but in atomic boolean it will provide atomicity to the operation in case the cpu switch happens in between.

Ruby on Rails: how to render a string as HTML?

since you are translating, and picking out your wanted code from a person's crappy coded file, could you use content_tag, in combo with your regex's.

Stealing from the api docs, you could interpolate this translated code into a content_tag like:

<%= content_tag translated_tag_type.to_sym, :class => "#{translated_class}" do -%>
<%= translated_text %>
<% end -%>
# => <div class="strong">Hello world!</div>

Not knowing your code, this kind of thinking will make sure your translated code is too compliant.

Objective C - Assign, Copy, Retain

Updated Answer for Changed Documentation

The information is now spread across several guides in the documentation. Here's a list of required reading:

The answer to this question now depends entirely on whether you're using an ARC-managed application (the modern default for new projects) or forcing manual memory management.

Assign vs. Weak - Use assign to set a property's pointer to the address of the object without retaining it or otherwise curating it; use weak to have the property point to nil automatically if the object assigned to it is deallocated. In most cases you'll want to use weak so you're not trying to access a deallocated object (illegal access of a memory address - "EXC_BAD_ACCESS") if you don't perform proper cleanup.

Retain vs. Copy - Declared properties use retain by default (so you can simply omit it altogether) and will manage the object's reference count automatically whether another object is assigned to the property or it's set to nil; Use copy to automatically send the newly-assigned object a -copy message (which will create a copy of the passed object and assign that copy to the property instead - useful (even required) in some situations where the assigned object might be modified after being set as a property of some other object (which would mean that modification/mutation would apply to the property as well).

How to get script of SQL Server data?

SQL Server Management Studio

This is your best tool for performing this task. You can generate a script that will build whichever tables you wish from a database as well as insert the data in those tables (as far as I know you have to export all of the data in the selected tables however).

To do this follow these steps:

  1. Right-click on your database and select Tasks > Generate Scripts

  2. In the Generate and Publish Scripts wizard, select the "Select specific database objects" option

  3. Expand the "Tables" tree and select all of the tables you wish to export the scheme and data for, then click Next

  4. In the next screen choose how you wish to save the script (the Output Type must remain set as "Save scripts to a specific location"), then click the Advanced button in the top right corner

  5. In the newly opened window, under the General section is a setting called "Types of data to script", set this to "Scheme and data" and click OK

  6. Click Next, review the export summary and click Next again. This will generate the script to your selected destination.

To restore your database, simply create a new database and change the first line of your generated script to USE [Your.New.Database.Name], then execute. Your new database will now have all of the tables and data you selected from the original database.

C# JSON Serialization of Dictionary into {key:value, ...} instead of {key:key, value:value, ...}

use property UseSimpleDictionaryFormat on DataContractJsonSerializer and set it to true.

Does the job :)

How to match all occurrences of a regex

Using scan should do the trick:


How to draw a path on a map using kml file?

Mathias Lin code working beautifully. However, you might want to consider changing this part inside drawPath method:

 if (lngLat.length >= 2 && gp1.getLatitudeE6() > 0 && gp1.getLongitudeE6() > 0
                    && gp2.getLatitudeE6() > 0 && gp2.getLongitudeE6() > 0) {

GeoPoint can be less than zero as well, I switch mine to:

     if (lngLat.length >= 2 && gp1.getLatitudeE6() != 0 && gp1.getLongitudeE6() != 0
                    && gp2.getLatitudeE6() != 0 && gp2.getLongitudeE6() != 0) {

Thank you :D

How do I do logging in C# without using 3rd party libraries?

I used to write my own error logging until I discovered ELMAH. I've never been able to get the emailing part down quite as perfectly as ELMAH does.

How to set a default entity property value with Hibernate

One solution is to have your getter check to see if whatever value you are working with is null (or whatever its non-initialized state would be) and if it's equal to that, just return your default value:

public String getStringValue(){
     return (this.stringValue == null) ? "Default" : stringValue;

How do you remove columns from a data.frame?

Use read.table with colClasses instances of "NULL" to avoid creating them in the first place:

## example data and temp file
x <- data.frame(x = 1:10, y = rnorm(10), z = runif(10), a = letters[1:10], stringsAsFactors = FALSE)
tmp <- tempfile()
write.table(x, tmp, row.names = FALSE)

(y <- read.table(tmp, colClasses = c("numeric", rep("NULL", 2), "character"), header = TRUE))

x a
1   1 a
2   2 b
3   3 c
4   4 d
5   5 e
6   6 f
7   7 g
8   8 h
9   9 i
10 10 j


What does the 'L' in front a string mean in C++?

It means the text is stored as wchar_t characters rather than plain old char characters.

(I originally said it meant unicode. I was wrong about that. But it can be used for unicode.)

Get data from php array - AJAX - jQuery

you cannot access array (php array) from js try

$array = array(1,2,3,4,5,6);
echo json_encode($array);

and js

$(document).ready( function() {
    $('#prev').click(function() {
            type: 'POST',
            url: 'ajax.php',
            data: 'id=testdata',
            dataType: 'json',
            cache: false,
            success: function(result) {

Most popular screen sizes/resolutions on Android phones

Another alternative to see popular android resolutions or aspect ratios is Unity statistics:

LATEST UNITY STATISTICS (on 2019.06 return http503) web arhive

Top on 2017-01:

Display Resolutions:

  • 1280 x 720: 28.9%
  • 1920 x 1080: 21.4%
  • 800 x 480: 10.3%
  • 854 x 480: 9.7%
  • 960 x 540: 8.9%
  • 1024 x 600: 7.8%
  • 1280 x 800: 5.0%
  • 2560 x 1440: 2.4%
  • 480 x 320: 1.2%
  • 1920 x 1200: 0.8%
  • 1024 x 768: 0.8%

Display Aspect Ratios:

  • 16:9: 72.4%
  • 5:3: 18.2%
  • 16:10: 6.2%
  • 4:3: 1.7%
  • 3:2: 1.2%
  • 5:4: 0.1%

How to customize the configuration file of the official PostgreSQL Docker image?

This works for me:

FROM postgres:9.6
USER postgres

# Copy postgres config file into container
COPY postgresql.conf /etc/postgresql

# Override default postgres config file
CMD ["postgres", "-c", "config_file=/etc/postgresql/postgresql.conf"]

Add items in array angular 4

Yes there is a way to do it.

First declare a class.

export class Custom
  name: string, 
  empoloyeeID: number

Then in your component import the class

import {Custom} from '../path/to/anyfile.ts'
export class FormComponent implements OnInit {
 name: string;
 empoloyeeID : number;
 empList: Array<Custom> = [];
 constructor() {


 ngOnInit() {
   let customObj = new Custom(); = "something";
   customObj.employeeId = 12; 
   this.empList.push(customObj); ="";
   this.empoloyeeID = 0; 

Another way would be to interfaces read the documentation once -

Also checkout this question, it is very interesting - When to use Interface and Model in TypeScript / Angular2

Safely remove migration In Laravel

I will rather do it manually

  1. Delete the model first (if you don't) need the model any longer
  2. Delete the migration from ...database/migrations folder
  3. If you have already migrated i.e if you have already run php artisan migrate, log into your phpmyadmin or SQL(whichever the case is) and in your database, delete the table created by the migration
  4. Still within your database, in the migrations folder, locate the row with that migration file name and delete the row.

Works for me, hope it helps!

Format the date using Ruby on Rails

@CMW's answer is bang on the money. I've added this answer as an example of how to configure an initializer so that both Date and Time objects get the formatting


date_formats = {
  concise: '%d-%b-%Y' # 13-Jan-2014

Time::DATE_FORMATS.merge! date_formats
Date::DATE_FORMATS.merge! date_formats

Also the following two commands will iterate through all the DATE_FORMATS in your current environment, and display today's date and time in each format:

Date::DATE_FORMATS.keys.each{|k| puts [k,].join(':- ')}
Time::DATE_FORMATS.keys.each{|k| puts [k,].join(':- ')}

How to connect wireless network adapter to VMWare workstation?

Here is a simple way to connect with your WIFI -

  1. Click on Edit from the menu section
  2. Virtual Network Editor
  3. Change Settings
  4. Add Network
  5. Select a network name
  6. Select Bridged option in VMnet Information -> Bridge to : Automatic
  7. Apply

That's it. You might be asked password to connect. Add it and you would be able to connect to the network.

Kind Regards,

Rahul Tilloo

jQuery how to bind onclick event to dynamically added HTML element

It is possible and sometimes necessary to create the click event along with the element. This is for example when selector based binding is not an option. The key part is to avoid the problem that Tobias was talking about by using .replaceWith() on a single element. Note that this is just a proof of concept.

    // This simulates the object to handle
    var staticObj = [
        { ID: '1', Name: 'Foo' },
        { ID: '2', Name: 'Foo' },
        { ID: '3', Name: 'Foo' }
    staticObj[1].children = [
        { ID: 'a', Name: 'Bar' },
        { ID: 'b', Name: 'Bar' },
        { ID: 'c', Name: 'Bar' }
    staticObj[1].children[1].children = [
        { ID: 'x', Name: 'Baz' },
        { ID: 'y', Name: 'Baz' }

    // This is the object-to-html-element function handler with recursion
    var handleItem = function( item ) {
        var ul, li = $("<li>" + item.ID + " " + item.Name + "</li>");

        if(typeof item.children !== 'undefined') {
            ul = $("<ul />");
            for (var i = 0; i < item.children.length; i++) {

        // This click handler actually does work {
        return li;

    // Wait for the dom instead of an ajax call or whatever
    $(function() {
        var ul = $("<ul />");

        for (var i = 0; i < staticObj.length; i++) {

        // Here; this works.
<div id="something">Magical ponies ?</div>

Why can a function modify some arguments as perceived by the caller, but not others?

Python is copy by value of reference. An object occupies a field in memory, and a reference is associated with that object, but itself occupies a field in memory. And name/value is associated with a reference. In python function, it always copy the value of the reference, so in your code, n is copied to be a new name, when you assign that, it has a new space in caller stack. But for the list, the name also got copied, but it refer to the same memory(since you never assign the list a new value). That is a magic in python!

How to Compare two Arrays are Equal using Javascript?

A more modern version:

function arraysEqual(a, b) {
  a = Array.isArray(a) ? a : [];
  b = Array.isArray(b) ? b : [];
  return a.length === b.length && a.every((el, ix) => el === b[ix]);

Coercing non-array arguments to empty arrays stops a.every() from exploding.

If you just want to see if the arrays have the same set of elements then you can use Array.includes():

function arraysContainSame(a, b) {
  a = Array.isArray(a) ? a : [];
  b = Array.isArray(b) ? b : [];
  return a.length === b.length && a.every(el => b.includes(el));

How To Use DateTimePicker In WPF?

I don't think this DateTimePicker has been mentioned before:

A WPF DateTimePicker That Works Like the One in Winforms

That one is in VB and has some bugs. I converted it to C# and made a new version with bug fixes.


Note: I used the Calendar control in WPFToolkit so that I could use .NET 3.5 instead of .NET 4. If you are using .NET 4, just remove references to "wpftc" in the XAML.

How do I loop through items in a list box and then remove those item?

How about:

foreach(var s in listBox1.Items.ToArray())
    //do stuff with (s);

The ToArray makes a copy of the list, so you don't need to worry about it changing the list while you are processing it.

How can I bind a background color in WPF/XAML?

I recommend reading the following blog post about debugging data binding:

And for this concrete issue: If you look at the compiler warnings, you will notice that you property has been hiding the Window.Background property (or Control or whatever class the property defines).

How do I make a redirect in PHP?


    $url = "targetpage"
    function redirect$url(){
        if (headers_sent()) == false{
            echo '<script>window.location.href="' . $url . '";</script>';

MongoDB inserts float when trying to insert integer

Well, it's JavaScript, so what you have in 'value' is a Number, which can be an integer or a float. But there's not really a difference in JavaScript. From Learning JavaScript:

The Number Data Type

Number data types in JavaScript are floating-point numbers, but they may or may not have a fractional component. If they don’t have a decimal point or fractional component, they’re treated as integers—base-10 whole numbers in a range of –253 to 253.

HTTP Status 405 - Method Not Allowed Error for Rest API

In above code variable "ver" is assign to null, print "ver" before returning and see the value. As this "ver" having null service is send status as "204 No Content".

And about status code "405 - Method Not Allowed" will get this status code when rest controller or service only supporting GET method but from client side your trying with POST with valid uri request, during such scenario get status as "405 - Method Not Allowed"

Execute stored procedure with an Output parameter?



ng-repeat: access key and value for each object in array of objects

seems like in Angular 1.3.12 you do not need the inner ng-repeat anymore, the outer loop returns the values of the collection is a single map entry

Return None if Dictionary key is not available

Wonder no more. It's built into the language.

    >>> help(dict)

    Help on class dict in module builtins:

    class dict(object)
     |  dict() -> new empty dictionary
     |  dict(mapping) -> new dictionary initialized from a mapping object's
     |      (key, value) pairs
     |  get(...)
     |      D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None.

Javascript window.print() in chrome, closing new window or tab instead of cancelling print leaves javascript blocked in parent window

OK here is what worked for me! I have a button on my left Nav. If you click it it will open a window and that window will load a document. After loading the document I want print the document then close the popup window immediately.

contentDiv.contentWindow.onfocus = function() {

Why does this work?
Well, after printing you set the onfocus event to close the window. The print popup will load so quickly that the onfocus event will not get a chance to trigger until you 1)print 2) cancel the print. Once you regain focus on the window, the window will close!
I hope that will work for you

Error Code 1292 - Truncated incorrect DOUBLE value - Mysql

I've seen a couple cases where this error occurs:

1. using the not equals operator != in a where clause with a list of multiple or values

such as:

where columnName !=('A'||'B')

This can be resolved by using

where columnName not in ('A','B')

2. missing a comparison operator in an if() function:

select if(col1,col1,col2);

in order to select the value in col1 if it exists and otherwise show the value in col2...this throws the error; it can be resolved by using:

select if(col1!='',col1,col2);

How do I enable index downloads in Eclipse for Maven dependency search?

  1. In Eclipse, click on Windows > Preferences, and then choose Maven in the left side.
  2. Check the box "Download repository index updates on startup".
    • Optionally, check the boxes Download Artifact Sources and Download Artifact JavaDoc.
  3. Click OK. The warning won't appear anymore.
  4. Restart Eclipse.

How to make a JFrame button open another JFrame class in Netbeans?

This link works with me: video

The answer posted before didn't work for me until the second click

So what I did is Directly call:

        new NewForm().setVisible(true);

        this.dispose();//to close the current jframe

What is the newline character in the C language: \r or \n?

What is the newline character in the C language: \r or \n?

The new-line may be thought of a some char and it has the value of '\n'. C11 5.2.1

This C new-line comes up in 3 places: C source code, as a single char and as an end-of-line in file I/O when in text mode.

  1. Many compilers will treat source text as ASCII. In that case, codes 10, sometimes 13, and sometimes paired 13,10 as new-line for source code. Had the source code been in another character set, different codes may be used. This new-line typically marks the end of a line of source code (actually a bit more complicated here), // comment, and # directives.

  2. In source code, the 2 characters \ and n represent the char new-line as \n. If ASCII is used, this char would have the value of 10.

  3. In file I/O, in text mode, upon reading the bytes of the input file (and stdin), depending on the environment, when bytes with the value(s) of 10 (Unix), 13,10, (*1) (Windows), 13 (Old Mac??) and other variations are translated in to a '\n'. Upon writing a file (or stdout), the reverse translation occurs.
    Note: File I/O in binary mode makes no translation.

The '\r' in source code is the carriage return char.

(*1) A lone 13 and/or 10 may also translate into \n.

HTML5 Local storage vs. Session storage

localStorage and sessionStorage both extend Storage. There is no difference between them except for the intended "non-persistence" of sessionStorage.

That is, the data stored in localStorage persists until explicitly deleted. Changes made are saved and available for all current and future visits to the site.

For sessionStorage, changes are only available per tab. Changes made are saved and available for the current page in that tab until it is closed. Once it is closed, the stored data is deleted.

count files in specific folder and display the number into 1 cel

Try below code :

Assign the path of the folder to variable FolderPath before running the below code.

Sub sample()

    Dim FolderPath As String, path As String, count As Integer
    FolderPath = "C:\Documents and Settings\Santosh\Desktop"

    path = FolderPath & "\*.xls"

    Filename = Dir(path)

    Do While Filename <> ""
       count = count + 1
        Filename = Dir()

    Range("Q8").Value = count
    'MsgBox count & " : files found in folder"
End Sub

build-impl.xml:1031: The module has not been deployed

if you still getting this error try this.

  1. Go to Netbeans services
  2. Remove Apache Tomcat.
  3. Add Apache Tomcat again.
  4. Build Project.
  5. Deploy Project

enter image description here

Prevent WebView from displaying "web page not available"

We can set the visibility of webView to 0(view.INVISIBLE) and show some message. This code works for my app running on lolipop.

    public void onReceivedError(WebView webView, int errorCode, String description, String failingUrl) {
        // hide webView content and show custom msg
        Toast.makeText(NrumWebViewActivity.this,getString(R.string.server_not_responding), Toast.LENGTH_SHORT).show();

    public void onReceivedError(WebView view, WebResourceRequest req, WebResourceError rerr) {
        // Redirect to deprecated method, so you can use it in all SDK versions
        onReceivedError(view, rerr.getErrorCode(), rerr.getDescription().toString(), req.getUrl().toString());

EF Code First "Invalid column name 'Discriminator'" but no inheritance

Old Q, but for also also happens (.NET Core 2.1) if you have a self-referencing navigation property ("Parent" or "Children" of the same type) but the Id property name isn't what EF expects. That is, I had an "Id" property on my class called WorkflowBase, and it had an array of related child steps, which were also of type WorkflowBase, and it kept trying to associate them with a non-existent "WorkflowBaseId" (the name i suppose it prefers as a natural/conventional default). I had to explicitly configure it using HasMany(), WithOne(), and HasConstraintName() to tell it how to traverse. But I spent a few hours thinking the problem was in 'locally' mapping the object's primary key, which i attempted to fix a bunch of different ways but which was probably always working.

PHP output showing little black diamonds with a question mark

You can also change the caracter set in your browser. Just for debug reasons.

Excel: Search for a list of strings within a particular string using array formulas?

This will return the matching word or an error if no match is found. For this example I used the following.

List of words to search for: G1:G7
Cell to search in: A1


Enter as an array formula by pressing Ctrl+Shift+Enter.

This formula works by first looking through the list of words to find matches, then recording the position of the word in the list as a positive value if it is found or as a negative value if it is not found. The largest value from this array is the position of the found word in the list. If no word is found, a negative value is passed into the INDEX() function, throwing an error.

To return the row number of a matching word, you can use the following:


This also must be entered as an array formula by pressing Ctrl+Shift+Enter. It will return -1 if no match is found.

Get all validation errors from Angular 2 FormGroup

I met the same problem and for finding all validation errors and displaying them, I wrote next method:

getFormValidationErrors() {
  Object.keys(this.productForm.controls).forEach(key => {

  const controlErrors: ValidationErrors = this.productForm.get(key).errors;
  if (controlErrors != null) {
        Object.keys(controlErrors).forEach(keyError => {
          console.log('Key control: ' + key + ', keyError: ' + keyError + ', err value: ', controlErrors[keyError]);

Form name productForm should be changed to yours.

It works in next way: we get all our controls from form in format {[p: string]: AbstractControl} and iterate by each error key, for get details of error. It skips null error values.

It also can be changed for displaying validation errors on the template view, just replace console.log(..) to what you need.

Convert timestamp to string

new Date().toString();

Dateformatter can make it to any string you want

How to use MySQL DECIMAL?

MySQL 5.x specification for decimal datatype is: DECIMAL[(M[,D])] [UNSIGNED] [ZEROFILL]. The answer above is wrong (now corrected) in saying that unsigned decimals are not possible.

To define a field allowing only unsigned decimals, with a total length of 6 digits, 4 of which are decimals, you would use: DECIMAL (6,4) UNSIGNED.

You can likewise create unsigned (ie. not negative) FLOAT and DOUBLE datatypes.

Update on MySQL 8.0.17+, as in MySQL 8 Manual: 11.1.1 Numeric Data Type Syntax:

"Numeric data types that permit the UNSIGNED attribute also permit SIGNED. However, these data types are signed by default, so the SIGNED attribute has no effect.*

As of MySQL 8.0.17, the UNSIGNED attribute is deprecated for columns of type FLOAT, DOUBLE, and DECIMAL (and any synonyms); you should expect support for it to be removed in a future version of MySQL. Consider using a simple CHECK constraint instead for such columns.

What is the intended use-case for git stash?

I know StackOverflow is not the place for opinion based answers, but I actually have a good opinion on when to shelve changes with a stash.

You don't want to commit you experimental changes

When you make changes in your workspace/working tree, if you need to perform any branch based operations like a merge, push, fetch or pull, you must be at a clean commit point. So if you have workspace changes you need to commit them. But what if you don't want to commit them? What if they are experimental? Something you don't want part of your commit history? Something you don't want others to see when you push to GitHub?

You don't want to lose local changes with a hard reset

In that case, you can do a hard reset. But if you do a hard reset you will lose all of your local working tree changes because everything gets overwritten to where it was at the time of the last commit and you'll lose all of your changes.

So, as for the answer of 'when should you stash', the answer is when you need to get back to a clean commit point with a synchronized working tree/index/commit, but you don't want to lose your local changes in the process. Just shelve your changes in a stash and you're good.

And once you've done your stash and then merged or pulled or pushed, you can just stash pop or apply and you're back to where you started from.

Git stash and GitHub

GitHub is constantly adding new features, but as of right now, there is now way to save a stash there. Again, the idea of a stash is that it's local and private. Nobody else can peek into your stash without physical access to your workstation. Kinda the same way git reflog is private with the git log is public. It probably wouldn't be private if it was pushed up to GitHub.

One trick might be to do a diff of your workspace, check the diff into your git repository, commit and then push. Then you can do a pull from home, get the diff and then unwind it. But that's a pretty messy way to achieve those results.

git diff > git-dif-file.diff

pop the stash

Could not load NIB in bundle

for me, it solved just by changing the name of my cell's file into the same as its class.

In Attributes Inspector(Third tab on the right side bar in story board):

  1. Set the cell's Identifier( for example: "MyCellId"),
  2. Set the cell's Class (for example: "MyCellClass" when the file is "MyCellClass") ,
  3. Register the cell in your view controller as follow:

    tableView.register(UINib(nibName: "MyCellClass", bundle: nil), forCellReuseIdentifier: "MyCellId")

.NET Global exception handler in console application

You also need to handle exceptions from threads:

static void Main(string[] args) {
Application.ThreadException += MYThreadHandler;

private void MYThreadHandler(object sender, Threading.ThreadExceptionEventArgs e)

Whoop, sorry that was for winforms, for any threads you're using in a console application you will have to enclose in a try/catch block. Background threads that encounter unhandled exceptions do not cause the application to end.

Where do I find the bashrc file on Mac?

Open Terminal and execute commands given below.

cd /etc
subl bashrc

subl denotes Sublime editor. You can replace subl with vi to open bashrc file in default editor. This will workout only if you have bashrc file, created earlier.

Synchronous XMLHttpRequest warning and <script>

Even the latest jQuery has that line, so you have these options:

  • Change the source of jQuery yourself - but maybe there is a good reason for its usage
  • Live with the warning, please note that this option is deprecated and not obsolete.
  • Change your code, so it does not use this function

I think number 2 is the most sensible course of action in this case.

By the way if you haven't already tried, try this out: $.ajaxSetup({async:true});, but I don't think it will work.

Local package.json exists, but node_modules missing

npm start runs a script that the app maker built for easy starting of the app npm install installs all the packages in package.json

run npm install first

then run npm start

clear data inside text file in c++

Deleting the file will also remove the content. See remove file.

Flutter plugin not installed error;. When running flutter doctor

You have to install Flutter and Dart both on Visual Studio Code as well as Android Studio!

Try using the following command:

flutter doctor --android-licenses, and press y to install all licenses.


Getting Java version at runtime

Example for Apache Commons Lang:

import org.apache.commons.lang.SystemUtils;

    Float version = SystemUtils.JAVA_VERSION_FLOAT;

    if (version < 1.4f) { 
        // legacy
    } else if (SystemUtils.IS_JAVA_1_5) {
        // 1.5 specific code
    } else if (SystemUtils.isJavaVersionAtLeast(1.6f)) {
        // 1.6 compatible code
    } else {
        // dodgy clause to catch 1.4 :)

split string only on first instance - java

String[] func(String apple){
String[] tmp = new String[2];
for(int i=0;i<apple.length;i++){
return tmp;
//returns string_ARRAY_!

i like writing own methods :)

How To Remove Outline Border From Input Button

Set both the outline and the box-shadow properties of the button to none and make them important.

input[type="button"] {
    outline: none !important;
    box-shadow: none !important;

The reason for setting the values to important is that, if you are using other CSS libraries or frameworks like Bootstrap, it might get overridden.

How/when to generate Gradle wrapper files?

  1. You will generate them once, but update them if you need a new feature or something from a plugin which in turn needs a newer gradle version.

    Easiest way to update: as of Gradle 2.2 you can just download and extract the complete or binary Gradle distribution, and run:

    $ <pathToExpandedZip>/bin/gradle wrapper

    No need to define a task, though you probably need some kind of build.gradle file.

    This will update or create the gradlew and gradlew.bat wrapper as well as gradle/wrapper/ and the gradle-wrapper.jar to provide the current version of gradle, wrapped.

  2. Those are all part of the wrapper.

  3. Some build.gradle files reference other files or files in subdirectories which are sub projects or modules. It gets a bit complicated, but if you have one project you basically need the one file.

  4. settings.gradle handles project, module and other kinds of names and settings, configures resusable variables for your gradle files if you like and you feel they would be clearer that way.

how to find my angular version in my project?

There are several ways you can do that:

  1. Go into node_modules/@angular/core/package.json and check version field.
  2. If you need to use it in your code, you can import it from the @angular/core:

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

  3. Inspect the rendered DOM - Angular adds the version to the main component element:

    <my-app ng-version="4.1.3">

Reverse Contents in Array

You can use the following example to reverse the contents in an array:

#include <iostream>

int main()
    int n, x;

    // order value for var x
    cin >> x;  

    // create array and the value for array is value var x
    int arr[x];

    // loop for insert values for array by reverse  
    for(int i=x; i > 0; i--) {

        // var i is number of elements in array 
        cin >> n;
        arr[i - 1] = n;

    // show element in array
    for(int l = 0; l < x; l++) {

    return 0;        

Connecting to local SQL Server database using C#

If you're using SQL Server express, change

SqlConnection conn = new SqlConnection("Server=localhost;" 
       + "Database=Database1;");


SqlConnection conn = new SqlConnection("Server=localhost\SQLExpress;" 
       + "Database=Database1;");

That, and hundreds more connection strings can be found at

What is the difference between BIT and TINYINT in MySQL?

Might be wrong but:

Tinyint is an integer between 0 and 255

bit is either 1 or 0

Therefore to me bit is the choice for booleans

CSS div element - how to show horizontal scroll bars only?

I also had to add white-space: nowrap; to the style, otherwise elements would wrap down into the area that we're removing the ability to scroll to.

Git reset single file in feature branch to be the same as in master

you are almost there; you just need to give the reference to master; since you want to get the file from the master branch:

git checkout master -- filename

Note that the differences will be cached; so if you want to see the differences you obtained; use

git diff --cached

Can you delete data from influxdb?

I'm surprised that nobody has mentioned InfluxDB retention policies for automatic data removal. You can set a default retention policy and also set them on a per-database level.

From the docs:

CREATE RETENTION POLICY <retention_policy_name> ON <database_name> DURATION <duration> REPLICATION <n> [DEFAULT]

invalid_grant trying to get oAuth token from google

Try change your url for requst to

Receive JSON POST with PHP


$data = json_decode(file_get_contents('php://input'), true);
echo $data["operacion"];

From your json and your code, it looks like you have spelled the word operation correctly on your end, but it isn't in the json.


Maybe also worth trying to echo the json string from php://input.

echo file_get_contents('php://input');

Jquery Change Height based on Browser Size/Resize

Building on Chad's answer, you also want to add that function to the onload event to ensure it is resized when the page loads as well.

jQuery.event.add(window, "load", resizeFrame);
jQuery.event.add(window, "resize", resizeFrame);

function resizeFrame() 
    var h = $(window).height();
    var w = $(window).width();
    $("#elementToResize").css('height',(h < 768 || w < 1024) ? 500 : 400);

jQuery attr() change img src

You remove the original image here:

newImg.animate(css, SPEED, function() {
    (callback || function() {})();

And all that's left behind is newImg. Then you reset link references the image using #rocket:

$("#rocket").attr('src', ...

But your newImg doesn't have an id attribute let alone an id of rocket.

To fix this, you need to remove img and then set the id attribute of newImg to rocket:

newImg.animate(css, SPEED, function() {
    var old_id = img.attr('id');
    newImg.attr('id', old_id);
    (callback || function() {})();

And then you'll get the shiny black rocket back again:

UPDATE: A better approach (as noted by mellamokb) would be to hide the original image and then show it again when you hit the reset button. First, change the reset action to something like this:

    $("#wrapper").css('top', '250px');
    $('.throbber, .morpher').remove(); // Clear out the new stuff.
    $("#rocket").show();               // Bring the original back.

And in the newImg.load function, grab the images original size:

var orig = {
    width: img.width(),
    height: img.height()

And finally, the callback for finishing the morphing animation becomes this:

newImg.animate(css, SPEED, function() {
    (callback || function() {})();

New and improved:

The leaking of $('.throbber, .morpher') outside the plugin isn't the best thing ever but it isn't a big deal as long as it is documented.

What is the difference between #import and #include in Objective-C?

#include it used to get "things" from another file to the one the #include is used in. Ex:

in file: main.cpp

#include "otherfile.h"

// some stuff here using otherfile.h objects,
// functions or classes declared inside

Header guard is used on the top of each header file (*.h) to prevent including the same file more then once (if it happens you will get compile errors).

in file: otherfile.h


// declare functions, classes or objects here


even if you put #include "otherfile.h" n time in your code, this inside it will not be redeclared.

How to enable file upload on React's Material UI simple input?

Here an example:

return (
    <Box alignItems='center' display='flex' justifyContent='center' flexDirection='column'>
        <input accept="image/*" id="upload-company-logo" type='file' hidden />
        <label htmlFor="upload-company-logo">
          <Button component="span" >
            <Paper elevation={5}>
              <Avatar src={formik.values.logo} className={classes.avatar} variant='rounded' />

How to use bluetooth to connect two iPhone?

If I remember correctly, Bluetooth defines certain roles that devices can take. Most cell phones only support a certain number of roles. For instance, I can have a Bluetooth stereo headset that connects to my phone to receive audio, but just because my cell phone has Bluetooth does mean that it supports BEING a speaker for a different device - it doesn't advertise its capabilities of having a speaker for use by other Bluetooth devices.

I assume you want to transfer files between two iPhones? Transferring files via Bluetooth does seem like functionality that I would put in the iPhone, but I'm not Apple so I don't know for sure. In fact, yes, it seems that file transfer is not supported except in jailbroken phones:

You'll probably get similar answers for Bluetooth Dial-Up Networking. I'd imagine they kept the Bluetooth commands out of the SDK for various reasons and you'll have to jailbreak your phone to get the functionality back.

JQuery Number Formatting

Using the jQuery Number Format plugin, you can get a formatted number in one of three ways:

// Return as a string
$.number( 1234.5678, 2 ); // Returns '1,234.57'

// Place formatted number directly in an element:
$('#mynum').number( 1234.5678 ); // #mynum would then contain '1,235'

// Replace existing number values in any element
$('span.num').number( true, 2 ); // Formats and replaces existing numbers in those elements.

If you don't like the format, or you need to localise, there are other parameters that let you choose how the number gets formatted:

.number( theNumber, decimalPlaces, decimalSeparator, thousandsSeparator )

You can also get jQuery Number Format from GitHub.

Set style for TextView programmatically

I do not believe you can set the style programatically. To get around this you can create a template layout xml file with the style assigned, for example in res/layout create tvtemplate.xml as with the following content:

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android=""
        android:text="This is a template"
        style="@style/my_style" />

then inflate this to instantiate your new TextView:

TextView myText = (TextView)getLayoutInflater().inflate(R.layout.tvtemplate, null);

Hope this helps.

adding css class to multiple elements

try this:

.button input, .button a {
//css here

That will apply the style to all a tags nested inside of <p class="button"></p>

JavaScript hide/show element

You should think JS for behaviour, and CSS for visual candy as much as possible. By changing your HTML a bit :

<td class="post">
    <a class="p-edit-btn" href="#" onclick="showStuff(this.parentNode);return false;">Edit</a>
    <span id="answer1" class="post-answer">
       <textarea rows="10" cols="115"></textarea>
    <span class="post-text" id="text1">Lorem ipsum ... </span>

You'll be able to switch from one view to the other simply using CSS rules : >, >, >
    display : none;

And JS code that switch between the two classes

<script type="text/javascript">
function showStuff(aPostTd) {

LDAP Authentication using Java

This is my LDAP Java login test application supporting LDAP:// and LDAPS:// self-signed test certificate. Code is taken from few SO posts, simplified implementation and removed legacy* imports.

I have run this in Windows7 and Linux machines against WinAD directory service. Application prints username and member groups.

$ java -cp classes test.LoginLDAP url=ldap:// [email protected] password=mypwd

$ java -cp classes test.LoginLDAP url=ldaps:// [email protected] password=mypwd

Test application supports temporary self-signed test certificates for ldaps:// protocol, this DummySSLFactory accepts any server cert so man-in-the-middle is possible. Real life installation should import server certificate to a local JKS keystore file and not using dummy factory.

Application uses enduser's username+password for initial context and ldap queries, it works for WinAD but don't know if can be used for all ldap server implementations. You could create context with internal username+pwd then run queries to see if given enduser is found.

package test;

import java.util.*;
import javax.naming.*;

public class LoginLDAP {

    public static void main(String[] args) throws Exception {
        Map<String,String> params = createParams(args);

        String url = params.get("url"); // ldap:// or ldaps://
        String principalName = params.get("username"); // [email protected]
        String domainName = params.get("domain"); // or empty

        if (domainName==null || "".equals(domainName)) {
            int delim = principalName.indexOf('@');
            domainName = principalName.substring(delim+1);

        Properties props = new Properties();
        props.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
        props.put(Context.PROVIDER_URL, url); 
        props.put(Context.SECURITY_PRINCIPAL, principalName); 
        props.put(Context.SECURITY_CREDENTIALS, params.get("password")); // secretpwd
        if (url.toUpperCase().startsWith("LDAPS://")) {
            props.put(Context.SECURITY_PROTOCOL, "ssl");
            props.put(Context.SECURITY_AUTHENTICATION, "simple");
            props.put("java.naming.ldap.factory.socket", "test.DummySSLSocketFactory");         

        InitialDirContext context = new InitialDirContext(props);
        try {
            SearchControls ctrls = new SearchControls();
            NamingEnumeration<SearchResult> results =,"(& (userPrincipalName="+principalName+")(objectClass=user))", ctrls);
                throw new AuthenticationException("Principal name not found");

            SearchResult result =;
            System.out.println("distinguisedName: " + result.getNameInNamespace() ); // CN=Firstname Lastname,OU=Mycity,DC=mydomain,DC=com

            Attribute memberOf = result.getAttributes().get("memberOf");
            if(memberOf!=null) {
                for(int idx=0; idx<memberOf.size(); idx++) {
                    System.out.println("memberOf: " + memberOf.get(idx).toString() ); // CN=Mygroup,CN=Users,DC=mydomain,DC=com
                    //Attribute att = context.getAttributes(memberOf.get(idx).toString(), new String[]{"CN"}).get("CN");
                    //System.out.println( att.get().toString() ); //  CN part of groupname
        } finally {
            try { context.close(); } catch(Exception ex) { }

     * Create "DC=sub,DC=mydomain,DC=com" string
     * @param domainName
     * @return
    private static String toDC(String domainName) {
        StringBuilder buf = new StringBuilder();
        for (String token : domainName.split("\\.")) {
            if(token.length()==0) continue;
            if(buf.length()>0)  buf.append(",");
        return buf.toString();

    private static Map<String,String> createParams(String[] args) {
        Map<String,String> params = new HashMap<String,String>();  
        for(String str : args) {
            int delim = str.indexOf('=');
            if (delim>0) params.put(str.substring(0, delim).trim(), str.substring(delim+1).trim());
            else if (delim==0) params.put("", str.substring(1).trim());
            else params.put(str, null);
        return params;


And SSL helper class.

package test;


public class DummySSLSocketFactory extends SSLSocketFactory {
    private SSLSocketFactory socketFactory;
    public DummySSLSocketFactory() {
        try {
          SSLContext ctx = SSLContext.getInstance("TLS");
          ctx.init(null, new TrustManager[]{ new DummyTrustManager()}, new SecureRandom());
          socketFactory = ctx.getSocketFactory();
        } catch ( Exception ex ){ throw new IllegalArgumentException(ex); }

      public static SocketFactory getDefault() { return new DummySSLSocketFactory(); }

      @Override public String[] getDefaultCipherSuites() { return socketFactory.getDefaultCipherSuites(); }
      @Override public String[] getSupportedCipherSuites() { return socketFactory.getSupportedCipherSuites(); }

      @Override public Socket createSocket(Socket socket, String string, int i, boolean bln) throws IOException {
        return socketFactory.createSocket(socket, string, i, bln);
      @Override public Socket createSocket(String string, int i) throws IOException, UnknownHostException {
        return socketFactory.createSocket(string, i);
      @Override public Socket createSocket(String string, int i, InetAddress ia, int i1) throws IOException, UnknownHostException {
        return socketFactory.createSocket(string, i, ia, i1);
      @Override public Socket createSocket(InetAddress ia, int i) throws IOException {
        return socketFactory.createSocket(ia, i);
      @Override public Socket createSocket(InetAddress ia, int i, InetAddress ia1, int i1) throws IOException {
        return socketFactory.createSocket(ia, i, ia1, i1);

class DummyTrustManager implements X509TrustManager {
    @Override public void checkClientTrusted(X509Certificate[] xcs, String str) {
        // do nothing
    @Override public void checkServerTrusted(X509Certificate[] xcs, String str) {
        /*System.out.println("checkServerTrusted for authType: " + str); // RSA
        for(int idx=0; idx<xcs.length; idx++) {
            X509Certificate cert = xcs[idx];
            System.out.println("X500Principal: " + cert.getSubjectX500Principal().getName());
    @Override public X509Certificate[] getAcceptedIssuers() {
        return new[0];

PostgreSQL: days/months/years between two dates

  AGE('2012-03-05', '2010-04-01'),
  DATE_PART('year', AGE('2012-03-05', '2010-04-01')) AS years,
  DATE_PART('month', AGE('2012-03-05', '2010-04-01')) AS months,
  DATE_PART('day', AGE('2012-03-05', '2010-04-01')) AS days;

This will give you full years, month, days ... between two dates:

          age          | years | months | days
 1 year 11 mons 4 days |     1 |     11 |    4

More detailed datediff information.

Export multiple classes in ES6 modules

For exporting the instances of the classes you can use this syntax:

// export index.js
const Foo = require('./my/module/foo');
const Bar = require('./my/module/bar');

module.exports = {
    Foo : new Foo(),
    Bar : new Bar()

// import and run method
const {Foo,Bar} = require('module_name');

telnet to port 8089 correct command

I believe telnet 8089 . Why don't u try both

Create list of single item repeated N times

As others have pointed out, using the * operator for a mutable object duplicates references, so if you change one you change them all. If you want to create independent instances of a mutable object, your xrange syntax is the most Pythonic way to do this. If you are bothered by having a named variable that is never used, you can use the anonymous underscore variable.

[e for _ in xrange(n)]

SQL Error: ORA-12899: value too large for column

As mentioned, the error message shows you the exact problem: you are passing 25 characters into a field set up to hold 20. You might also want to consider defining the columns a little more precisely. You can define whether the VARCHAR2 column will store a certain number of bytes or characters. You may encounter a problem in the future where you try to insert a multi byte character into the field, for example this is 5 characters in length but it won't fit into 5 bytes: 'ÀÈÌÕÛ'

Here is an example:

CREATE TABLE Customers(CustomerID  VARCHAR2(9 BYTE), ...


CREATE TABLE Customers(CustomerID  VARCHAR2(9 CHAR), ...

What's the difference between Visual Studio Community and other, paid versions?

Check the following: Visual studio community is free version for students and other academics, individual developers, open-source projects, and small non-enterprise teams (see "Usage" section at bottom of linked page). While VSUltimate is for companies. You also get more things with paid versions!

converting epoch time with milliseconds to datetime

Use datetime.datetime.fromtimestamp:

>>> import datetime
>>> s = 1236472051807 / 1000.0
>>> datetime.datetime.fromtimestamp(s).strftime('%Y-%m-%d %H:%M:%S.%f')
'2009-03-08 09:27:31.807000'

%f directive is only supported by datetime.datetime.strftime, not by time.strftime.

UPDATE Alternative using %, str.format:

>>> import time
>>> s, ms = divmod(1236472051807, 1000)  # (1236472051, 807)
>>> '%s.%03d' % (time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(s)), ms)
'2009-03-08 00:27:31.807'
>>> '{}.{:03d}'.format(time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(s)), ms)
'2009-03-08 00:27:31.807'

Why does Eclipse automatically add appcompat v7 library support whenever I create a new project?

Sorry with my English, When you create a new android project, you should choose api of high level, for example: from api 17 to api 21, It will not have appcompat and very easy to share project. If you did it with lower API, you just edit in Android Manifest to have upper API :), after that, you can delete Appcompat V7.

Create a new txt file using VB.NET

open C:\myfile.txt for append as #1
write #1, text1.text, text2.text

This is the code I use in Visual Basic 6.0. It helps me to create a txt file on my drive, write two pieces of data into it, and then close the file... Give it a try...

Rails: How do I create a default value for attributes in Rails activerecord's model?

Just strengthening Jim's answer

Using presence one can do

class Task < ActiveRecord::Base
  before_save :default_values
  def default_values
    self.status = status.presence || 'P'

Output of git branch in tree like fashion

The answer below uses git log:

I mentioned a similar approach in 2009 with "Unable to show a Git tree in terminal":

git log --graph --pretty=oneline --abbrev-commit

But the full one I have been using is in "How to display the tag name and branch name using git log --graph" (2011):

git config --global alias.lgb "log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset%n' --abbrev-commit --date=relative --branches"

git lgb

Original answer (2010)

git show-branch --list comes close of what you are looking for (with the topo order)


By default, the branches and their commits are shown in reverse chronological order.
This option makes them appear in topological order (i.e., descendant commits are shown before their parents).

But the tool git wtf can help too. Example:

$ git wtf
Local branch: master
[ ] NOT in sync with remote (needs push)
    - Add before-search hook, for shortcuts for custom search queries. [4430d1b] (edwardzyang@...; 7 days ago)
Remote branch: origin/master ([email protected]:sup/mainline.git)
[x] in sync with local

Feature branches:
{ } origin/release-0.8.1 is NOT merged in (1 commit ahead)
    - bump to 0.8.1 [dab43fb] (wmorgan-sup@...; 2 days ago)
[ ] labels-before-subj is NOT merged in (1 commit ahead)
    - put labels before subject in thread index view [790b64d] (marka@...; 4 weeks ago)
{x} origin/enclosed-message-display-tweaks merged in
(x) experiment merged in (only locally)

NOTE: working directory contains modified files

git-wtf shows you:

  • How your branch relates to the remote repo, if it's a tracking branch.
  • How your branch relates to non-feature ("version") branches, if it's a feature branch.
  • How your branch relates to the feature branches, if it's a version branch

How to use sbt from behind proxy?

sbt works in a fairly standard way comparing to the way other JVM-based projects are usually configured.

sbt is in fact two "subsystems" - the launcher and the core. It's usually xsbt.boot.Boot that gets executed before the core starts up with the features we all know (and some even like).

It's therefore a matter of how you execute sbt that says how you could set up a proxy for HTTP, HTTPS and FTP network traffic.

The following is the entire list of the available properties that can be set for any Java application, sbt including, that instruct the Java API to route communication through a proxy:

  • http_proxy
  • http_proxy_user
  • http_proxy_pass
  • http.proxyHost
  • http.proxyPort
  • http.proxyUser
  • http.proxyPassword

Replace http above with https and ftp to get the list of the properties for the services.

Some sbt scripts use JAVA_OPTS to set up the proxy settings with -Dhttp.proxyHost and -Dhttp.proxyPort amongst the others (listed above). See Java Networking and Proxies.

Some scripts come with their own way of setting up proxy configuration using the SBT_OPTS property, .sbtopts or (only on Windows) %SBT_HOME%\conf\sbtconfig.txt. You can use them to specifically set sbt to use proxies while the other JVM-based applications are not affected at all.

From the sbt command line tool:

# jvm options and output control
JAVA_OPTS          environment variable, if unset uses "$java_opts"
SBT_OPTS           environment variable, if unset uses "$default_sbt_opts"
.sbtopts           if this file exists in the current directory, it is
                   prepended to the runner args
/etc/sbt/sbtopts   if this file exists, it is prepended to the runner args
-Dkey=val          pass -Dkey=val directly to the java runtime
-J-X               pass option -X directly to the java runtime 
                   (-J is stripped)
-S-X               add -X to sbt's scalacOptions (-S is stripped)

And here comes an excerpt from sbt.bat:

@REM Envioronment:
@REM JAVA_HOME - location of a JDK home dir (mandatory)
@REM SBT_OPTS  - JVM options (optional)
@REM Configuration:
@REM sbtconfig.txt found in the SBT_HOME.

Be careful with sbtconfig.txt that just works on Windows only. When you use cygwin the file is not consulted and you will have to resort to using the other approaches.

I'm using sbt with the following script:

$JAVA_HOME/bin/java $SBT_OPTS -jar /Users/jacek/.ivy2/local/org.scala-sbt/sbt-launch/$SBT_LAUNCHER_VERSION-SNAPSHOT/jars/sbt-launch.jar "$@"

The point of the script is to use the latest version of sbt built from the sources (that's why I'm using /Users/jacek/.ivy2/local/org.scala-sbt/sbt-launch/$SBT_LAUNCHER_VERSION-SNAPSHOT/jars/sbt-launch.jar) with $SBT_OPTS property as a means of passing JVM properties to the JVM sbt uses.

The script above lets me to set proxy on command line on MacOS X as follows:

SBT_OPTS="-Dhttp.proxyHost=proxyhost -Dhttp.proxyPort=9999" sbt

As you can see, there are many approaches to set proxy for sbt that all pretty much boil down to set a proxy for the JVM sbt uses.

MySQL select rows where left join is null

One of the best approach if you do not want to return any columns from table2 is to use the NOT EXISTS

FROM    table1 T1
              FROM table2 T2
              WHERE = T2.user_one
                  OR = T2.user_two)

Semantically this says what you want to query: Select every row where there is no matching record in the second table.

MySQL is optimized for EXISTS: It returns as soon as it finds the first matching record.

How to pass the id of an element that triggers an `onclick` event to the event handling function

Instead of passing the ID, you can just pass the element itself:

<link onclick="doWithThisElement(this)" />

Or, if you insist on passing the ID:

<link id="foo" onclick="doWithThisElement(" />

Here's the JSFiddle Demo:

Convert normal date to unix timestamp

After comparing timestamp with the one from PHP, none of the above seems correct for my timezone. The code below gave me same result as PHP which is most important for the project I am doing.

function getTimeStamp(input) {_x000D_
    var parts = input.trim().split(' ');_x000D_
    var date = parts[0].split('-');_x000D_
 var time = (parts[1] ? parts[1] : '00:00:00').split(':');_x000D_
 // NOTE:: Month: 0 = January - 11 = December._x000D_
 var d = new Date(date[0],date[1]-1,date[2],time[0],time[1],time[2]);_x000D_
 return d.getTime() / 1000;_x000D_
// USAGE::_x000D_
var start = getTimeStamp('2017-08-10');_x000D_
var end = getTimeStamp('2017-08-10 23:59:59');_x000D_
console.log(start + ' - ' + end);

I am using this on NodeJS, and we have timezone 'Australia/Sydney'. So, I had to add this on .env file:

TZ = 'Australia/Sydney'

Above is equivalent to:

process.env.TZ = 'Australia/Sydney'

Kubernetes Pod fails with CrashLoopBackOff

The issue caused by the docker container which exits as soon as the "start" process finishes. i added a command that runs forever and it worked. This issue mentioned here

foreach vs someList.ForEach(){}

For fun, I popped List into reflector and this is the resulting C#:

public void ForEach(Action<T> action)
    if (action == null)
    for (int i = 0; i < this._size; i++)

Similarly, the MoveNext in Enumerator which is what is used by foreach is this:

public bool MoveNext()
    if (this.version != this.list._version)
    if (this.index < this.list._size)
        this.current = this.list._items[this.index];
        return true;
    this.index = this.list._size + 1;
    this.current = default(T);
    return false;

The List.ForEach is much more trimmed down than MoveNext - far less processing - will more likely JIT into something efficient..

In addition, foreach() will allocate a new Enumerator no matter what. The GC is your friend, but if you're doing the same foreach repeatedly, this will make more throwaway objects, as opposed to reusing the same delegate - BUT - this is really a fringe case. In typical usage you will see little or no difference.

How to convert all tables in database to one collation?

For phpMyAdmin I figured this out:

WHERE TABLE_SCHEMA="yourtableschemaname"

Just change yourtableschemaname and you're fine.

How to delete a selected DataGridViewRow and update a connected database table?

It Work for me !

private: System::Void MyButton_Delete_Click(System::Object^ sender, System::EventArgs^ e) {
    // ??????? ???????(Row).

How to style HTML5 range input to have different color before and after slider?

While the accepted answer is good in theory, it ignores the fact that the thumb then cannot be bigger than size of the track without being chopped off by the overflow: hidden. See this example of how to handle this with just a tiny bit of JS.

// .chrome styling Vanilla JS

document.getElementById("myinput").oninput = function() {
  var value = (this.value-this.min)/(this.max-this.min)*100 = 'linear-gradient(to right, #82CFD0 0%, #82CFD0 ' + value + '%, #fff ' + value + '%, white 100%)'
#myinput {
  background: linear-gradient(to right, #82CFD0 0%, #82CFD0 50%, #fff 50%, #fff 100%);
  border: solid 1px #82CFD0;
  border-radius: 8px;
  height: 7px;
  width: 356px;
  outline: none;
  transition: background 450ms ease-in;
  -webkit-appearance: none;
<div class="chrome">
  <input id="myinput" min="0" max="60" type="range" value="30" />

Show div on scrollDown after 800px

You can also, do this.

$(window).on("scroll", function () {
   if ($(this).scrollTop() > 800) {
      #code here
   } else {
      #code here

c++ Read from .csv file

That because your csv file is in invalid format, maybe the line break in your text file is not the \n or \r

and, using c/c++ to parse text is not a good idea. try awk:

 $awk -F"," '{print "ID="$1"\tName="$2"\tAge="$3"\tGender="$4}' 1.csv
 ID=0   Name=Filipe Age=19  Gender=M
 ID=1   Name=Maria  Age=20  Gender=F
 ID=2   Name=Walter Age=60  Gender=M

HTML Display Current date

Here's one way. You have to get the individual components from the date object (day, month & year) and then build and format the string however you wish.

n =  new Date();_x000D_
y = n.getFullYear();_x000D_
m = n.getMonth() + 1;_x000D_
d = n.getDate();_x000D_
document.getElementById("date").innerHTML = m + "/" + d + "/" + y;
<p id="date"></p>

Postgresql, update if row with some unique value exists, else insert

I found this post more relevant in this scenario:

WITH upsert AS (
     UPDATE spider_count SET tally=tally+1 
     WHERE date='today' AND spider='Googlebot' 
INSERT INTO spider_count (spider, tally) 
SELECT 'Googlebot', 1 

How to square all the values in a vector in R?

Try this (faster and simpler):

newData <- data^2

How to convert list of key-value tuples into dictionary?

l=[['A', 1], ['B', 2], ['C', 3]]
for i,j in l:

C programming: Dereferencing pointer to incomplete type error

You haven't defined struct stasher_file by your first definition. What you have defined is an nameless struct type and a variable stasher_file of that type. Since there's no definition for such type as struct stasher_file in your code, the compiler complains about incomplete type.

In order to define struct stasher_file, you should have done it as follows

struct stasher_file {
 char name[32];
 int  size;
 int  start;
 int  popularity;

Note where the stasher_file name is placed in the definition.

How do I calculate percentiles with python/numpy?

A convenient way to calculate percentiles for a one-dimensional numpy sequence or matrix is by using numpy.percentile <>. Example:

import numpy as np

a = np.array([0,1,2,3,4,5,6,7,8,9,10])
p50 = np.percentile(a, 50) # return 50th percentile, e.g median.
p90 = np.percentile(a, 90) # return 90th percentile.
print('median = ',p50,' and p90 = ',p90) # median =  5.0  and p90 =  9.0

However, if there is any NaN value in your data, the above function will not be useful. The recommended function to use in that case is the numpy.nanpercentile <> function:

import numpy as np

a_NaN = np.array([0.,1.,2.,3.,4.,5.,6.,7.,8.,9.,10.])
a_NaN[0] = np.nan
p50 = np.nanpercentile(a_NaN, 50) # return 50th percentile, e.g median.
p90 = np.nanpercentile(a_NaN, 90) # return 90th percentile.
print('median = ',p50,' and p90 = ',p90) # median =  5.5  and p90 =  9.1

In the two options presented above, you can still choose the interpolation mode. Follow the examples below for easier understanding.

import numpy as np

b = np.array([1,2,3,4,5,6,7,8,9,10])
print('percentiles using default interpolation')
p10 = np.percentile(b, 10) # return 10th percentile.
p50 = np.percentile(b, 50) # return 50th percentile, e.g median.
p90 = np.percentile(b, 90) # return 90th percentile.
print('p10 = ',p10,', median = ',p50,' and p90 = ',p90)
#p10 =  1.9 , median =  5.5  and p90 =  9.1

print('percentiles using interpolation = ', "linear")
p10 = np.percentile(b, 10,interpolation='linear') # return 10th percentile.
p50 = np.percentile(b, 50,interpolation='linear') # return 50th percentile, e.g median.
p90 = np.percentile(b, 90,interpolation='linear') # return 90th percentile.
print('p10 = ',p10,', median = ',p50,' and p90 = ',p90)
#p10 =  1.9 , median =  5.5  and p90 =  9.1

print('percentiles using interpolation = ', "lower")
p10 = np.percentile(b, 10,interpolation='lower') # return 10th percentile.
p50 = np.percentile(b, 50,interpolation='lower') # return 50th percentile, e.g median.
p90 = np.percentile(b, 90,interpolation='lower') # return 90th percentile.
print('p10 = ',p10,', median = ',p50,' and p90 = ',p90)
#p10 =  1 , median =  5  and p90 =  9

print('percentiles using interpolation = ', "higher")
p10 = np.percentile(b, 10,interpolation='higher') # return 10th percentile.
p50 = np.percentile(b, 50,interpolation='higher') # return 50th percentile, e.g median.
p90 = np.percentile(b, 90,interpolation='higher') # return 90th percentile.
print('p10 = ',p10,', median = ',p50,' and p90 = ',p90)
#p10 =  2 , median =  6  and p90 =  10

print('percentiles using interpolation = ', "midpoint")
p10 = np.percentile(b, 10,interpolation='midpoint') # return 10th percentile.
p50 = np.percentile(b, 50,interpolation='midpoint') # return 50th percentile, e.g median.
p90 = np.percentile(b, 90,interpolation='midpoint') # return 90th percentile.
print('p10 = ',p10,', median = ',p50,' and p90 = ',p90)
#p10 =  1.5 , median =  5.5  and p90 =  9.5

print('percentiles using interpolation = ', "nearest")
p10 = np.percentile(b, 10,interpolation='nearest') # return 10th percentile.
p50 = np.percentile(b, 50,interpolation='nearest') # return 50th percentile, e.g median.
p90 = np.percentile(b, 90,interpolation='nearest') # return 90th percentile.
print('p10 = ',p10,', median = ',p50,' and p90 = ',p90)
#p10 =  2 , median =  5  and p90 =  9

If your input array only consists of integer values, you might be interested in the percentil answer as an integer. If so, choose interpolation mode such as ‘lower’, ‘higher’, or ‘nearest’.

conversion from string to json object android

To get a JSONObject or JSONArray from a String I've created this class:

public static class JSON {

     public Object obj = null;
     public boolean isJsonArray = false;

     JSON(Object obj, boolean isJsonArray){
         this.obj = obj;
         this.isJsonArray = isJsonArray;

Here to get the JSON:

public static JSON fromStringToJSON(String jsonString){

    boolean isJsonArray = false;
    Object obj = null;

    try {
        JSONArray jsonArray = new JSONArray(jsonString);
        Log.d("JSON", jsonArray.toString());
        obj = jsonArray;
        isJsonArray = true;
    catch (Throwable t) {
        Log.e("JSON", "Malformed JSON: \"" + jsonString + "\"");

    if (object == null) {
        try {
            JSONObject jsonObject = new JSONObject(jsonString);
            Log.d("JSON", jsonObject.toString());
            obj = jsonObject;
            isJsonArray = false;
        } catch (Throwable t) {
            Log.e("JSON", "Malformed JSON: \"" + jsonString + "\"");

    return new JSON(obj, isJsonArray);


JSON json = fromStringToJSON("{\"message\":\"ciao\"}");
if (json.obj != null) {

    // If the String is a JSON array
    if (json.isJsonArray) {
        JSONArray jsonArray = (JSONArray) json.obj;
    // If it's a JSON object
    else {
        JSONObject jsonObject = (JSONObject) json.obj;

How to add spacing between UITableViewCell

I think this is the cleanest solution:

class MyTableViewCell: UITableViewCell {
    override func awakeFromNib() {
        layoutMargins = UIEdgeInsetsMake(8, 0, 8, 0)

Obtain form input fields using jQuery?

Sometimes I find getting one at a time is more useful. For that, there's this:

var input_name = "firstname";
var input = $("#form_id :input[name='"+input_name+"']");