Programs & Examples On #Ddd repositories

A Repository is a mechanism for encapsulating storage, retrieval, and search behavior which emulates a collection of objects.

What's an Aggregate Root?

In the context of the repository pattern, aggregate roots are the only objects your client code loads from the repository.

The repository encapsulates access to child objects - from a caller's perspective it automatically loads them, either at the same time the root is loaded or when they're actually needed (as with lazy loading).

For example, you might have an Order object which encapsulates operations on multiple LineItem objects. Your client code would never load the LineItem objects directly, just the Order that contains them, which would be the aggregate root for that part of your domain.

How do you increase the max number of concurrent connections in Apache?

change the MaxClients directive. it is now on 256.

Open new Terminal Tab from command line (Mac OS X)

What about this simple snippet, based on a standard script command (echo):

# set mac osx's terminal title to "My Title"
echo -n -e "\033]0;My Title\007"

How to get the indices list of all NaN value in numpy array?

You can use np.where to match the boolean conditions corresponding to Nan values of the array and map each outcome to generate a list of tuples.

>>>list(map(tuple, np.where(np.isnan(x))))
[(1, 2), (2, 0)]

How to access command line arguments of the caller inside a function?

Ravi's comment is essentially the answer. Functions take their own arguments. If you want them to be the same as the command-line arguments, you must pass them in. Otherwise, you're clearly calling a function without arguments.

That said, you could if you like store the command-line arguments in a global array to use within other functions:

my_function() {
    echo "stored arguments:"
    for arg in "${commandline_args[@]}"; do
        echo "    $arg"



You have to access the command-line arguments through the commandline_args variable, not $@, $1, $2, etc., but they're available. I'm unaware of any way to assign directly to the argument array, but if someone knows one, please enlighten me!

Also, note the way I've used and quoted $@ - this is how you ensure special characters (whitespace) don't get mucked up.

How is malloc() implemented internally?

The sbrksystem call moves the "border" of the data segment. This means it moves a border of an area in which a program may read/write data (letting it grow or shrink, although AFAIK no malloc really gives memory segments back to the kernel with that method). Aside from that, there's also mmap which is used to map files into memory but is also used to allocate memory (if you need to allocate shared memory, mmap is how you do it).

So you have two methods of getting more memory from the kernel: sbrk and mmap. There are various strategies on how to organize the memory that you've got from the kernel.

One naive way is to partition it into zones, often called "buckets", which are dedicated to certain structure sizes. For example, a malloc implementation could create buckets for 16, 64, 256 and 1024 byte structures. If you ask malloc to give you memory of a given size it rounds that number up to the next bucket size and then gives you an element from that bucket. If you need a bigger area malloc could use mmap to allocate directly with the kernel. If the bucket of a certain size is empty malloc could use sbrk to get more space for a new bucket.

There are various malloc designs and there is propably no one true way of implementing malloc as you need to make a compromise between speed, overhead and avoiding fragmentation/space effectiveness. For example, if a bucket runs out of elements an implementation might get an element from a bigger bucket, split it up and add it to the bucket that ran out of elements. This would be quite space efficient but would not be possible with every design. If you just get another bucket via sbrk/mmap that might be faster and even easier, but not as space efficient. Also, the design must of course take into account that "free" needs to make space available to malloc again somehow. You don't just hand out memory without reusing it.

If you're interested, the OpenSER/Kamailio SIP proxy has two malloc implementations (they need their own because they make heavy use of shared memory and the system malloc doesn't support shared memory). See:

Then you could also have a look at the GNU libc malloc implementation, but that one is very complicated, IIRC.

How to filter rows containing a string pattern from a Pandas dataframe

>>> mask = df['ids'].str.contains('ball')    
>>> mask
0     True
1     True
2    False
3     True
Name: ids, dtype: bool

>>> df[mask]
     ids  vals
0  aball     1
1  bball     2
3  fball     4

Regex that matches integers in between whitespace or start/end of string only


will accept numbers with leading "+", leading "-" and leadings "0"

CSS to keep element at "fixed" position on screen

Make sure your content is kept in a div, say divfix.

<div id="divfix">Your Code goes here</div>


#divfix {
       bottom: 0;
       right: 0;
       position: fixed;
       z-index: 3000;

Hope ,It will help you..

Java, How to add library files in netbeans?

In Netbeans 8.2

1. Dowload the binaries from the web source. The Apache Commos are in: [][1] In this case, you must select the "Logging" in the Components menu and follow the link to downloads in the Releases part. Direct URL: [][2] For me, the correct download was the file: from the Binaries.

2. Unzip downloaded content. Now, you can see several jar files inside the directory created from the zip file.

3. Add the library to the project. Right click in the project, select Properties and click in Libraries (in the left side). Click the button "Add Jar/Folder". Go to the previously unzipped contents and select the properly jar file. Clic in "Open" and click in"Ok". The library has been loaded!

How do I share variables between different .c files?

In 99.9% of all cases it is bad program design to share non-constant, global variables between files. There are very few cases when you actually need to do this: they are so rare that I cannot come up with any valid cases. Declarations of hardware registers perhaps.

In most of the cases, you should either use (possibly inlined) setter/getter functions ("public"), static variables at file scope ("private"), or incomplete type implementations ("private") instead.

In those few rare cases when you need to share a variable between files, do like this:

// file.h
extern int my_var;

// file.c
#include "file.h"
int my_var = something;

// main.c
#include "file.h"

Never put any form of variable definition in a h-file.

Remove scroll bar track from ScrollView in Android

By using below, solved the problem


Regex for numbers only

Regex regex = new Regex ("^[0-9]{1,4}=[0-9]{1,4]$")

stop all instances of node.js server

if you want to kill a specific node process , you can go to command line route and type:

ps aux | grep node

to get a list of all node process ids. now you can get your process id(pid), then do:

kill -9 PID

and if you want to kill all node processes then do:

killall -9 node

-9 switch is like end task on windows. it will force the process to end. you can do:

kill -l

to see all switches of kill command and their comments.

Node.js ES6 classes with require

Yes, your example would work fine.

As for exposing your classes, you can export a class just like anything else:

class Animal {...}
module.exports = Animal;

Or the shorter:

module.exports = class Animal {


Once imported into another module, then you can treat it as if it were defined in that file:

var Animal = require('./Animal');

class Cat extends Animal {

HTML5 pattern for formatting input box to take date mm/dd/yyyy?

Below pattern perfectly works in case of leap year and as well as with normal dates. The date format is : YYYY-MM-DD

<input type="text"  placeholder="YYYY-MM-DD" pattern="(?:19|20)(?:(?:[13579][26]|[02468][048])-(?:(?:0[1-9]|1[0-2])-(?:0[1-9]|1[0-9]|2[0-9])|(?:(?!02)(?:0[1-9]|1[0-2])-(?:30))|(?:(?:0[13578]|1[02])-31))|(?:[0-9]{2}-(?:0[1-9]|1[0-2])-(?:0[1-9]|1[0-9]|2[0-8])|(?:(?!02)(?:0[1-9]|1[0-2])-(?:29|30))|(?:(?:0[13578]|1[02])-31)))" class="form-control "  name="eventDate" id="" required autofocus autocomplete="nope">

I got this solution from Hope it may help someone.

Dynamically Add Images React Webpack

If you are bundling your code at the server-side, then there is nothing stopping you from requiring assets directly from jsx:

  <img src={require('./assets/image.png')} />

Hide HTML element by id

If you want to do it via javascript rather than CSS you can use:

var link = document.getElementById('nav-ask'); = 'none'; //or = 'hidden';

depending on what you want to do.

How to get the html of a div on another page with jQuery ajax?

If you are looking for content from different domain this will do the trick:

    url:'' +
        success: function(data){

How to print a debug log?

You can use the php curl module to make calls to This works great in an secure, corporate environment where certain restrictions in the php.ini exists that restrict usage of file_put_contents.

How can I convert a string to a number in Perl?

Perl is a context-based language. It doesn't do its work according to the data you give it. Instead, it figures out how to treat the data based on the operators you use and the context in which you use them. If you do numbers sorts of things, you get numbers:

# numeric addition with strings:
my $sum = '5.45' + '0.01'; # 5.46

If you do strings sorts of things, you get strings:

# string replication with numbers:
my $string = ( 45/2 ) x 4; # "22.522.522.522.5"

Perl mostly figures out what to do and it's mostly right. Another way of saying the same thing is that Perl cares more about the verbs than it does the nouns.

Are you trying to do something and it isn't working?

C# - Simplest way to remove first occurrence of a substring from another string

string myString = sourceString.Remove(sourceString.IndexOf(removeString),removeString.Length);

EDIT: @OregonGhost is right. I myself would break the script up with conditionals to check for such an occurence, but I was operating under the assumption that the strings were given to belong to each other by some requirement. It is possible that business-required exception handling rules are expected to catch this possibility. I myself would use a couple of extra lines to perform conditional checks and also to make it a little more readable for junior developers who may not take the time to read it thoroughly enough.

CSS background image alt attribute

The general belief is that you shouldn't be using background images for things with meaningful semantic value so there isn't really a proper way to store alt data with those images. The important question is what are you going to be doing with that alt data? Do you want it to display if the images don't load? Do you need it for some programmatic function on the page? You could store the data arbitrarily using made up css properties that have no meaning (might cause errors?) OR by adding in hidden images that have the image and the alt tag, and then when you need a background images alt you can compare the image paths and then handle the data however you want using some custom script to simulate what you need. There's no way I know of to make the browser automatically handle some sort of alt attribute for background images though.

How to determine the version of the C++ standard used by the compiler?

Use __cplusplus as suggested. Only one note for Microsoft compiler, use Zc:__cplusplus compiler switch to enable __cplusplus


How do you performance test JavaScript code?

I usually just test javascript performance, how long script runs. jQuery Lover gave a good article link for testing javascript code performance, but the article only shows how to test how long your javascript code runs. I would also recommend reading article called "5 tips on improving your jQuery code while working with huge data sets".

Javascript: Unicode string to hex

how do you get "\u6f22\u5b57" from ?? in JavaScript?

These are JavaScript Unicode escape sequences e.g. \u12AB. To convert them, you could iterate over every code unit in the string, call .toString(16) on it, and go from there.

However, it is more efficient to also use hexadecimal escape sequences e.g. \xAA in the output wherever possible.

Also note that ASCII symbols such as A, b, and - probably don’t need to be escaped.

I’ve written a small JavaScript library that does all this for you, called jsesc. It has lots of options to control the output.

Here’s an online demo of the tool in action:

Your question was tagged as utf-8. Reading the rest of your question, UTF-8 encoding/decoding didn’t seem to be what you wanted here, but in case you ever need it: use utf8.js (online demo).

Count the number occurrences of a character in a string

This easy and straight forward function might help:

def check_freq(x):
    freq = {}
    for c in set(x):
       freq[c] = x.count(c)
    return freq

{'a': 7, 'b': 14, 'c': 3, 'd': 3}

If a comprehension is desired:

def check_freq(x):
    return {c: x.count(c) for c in set(x)}

Converting A String To Hexadecimal In Java

new BigInteger(1, myString.getBytes(/*YOUR_CHARSET?*/)).toString(16)

Search a string in a file and delete it from this file by Shell Script

This should do it:

sed -e s/deletethis//g -i *
sed -e "s/deletethis//g" -i.backup *
sed -e "s/deletethis//g" -i .backup *

it will replace all occurrences of "deletethis" with "" (nothing) in all files (*), editing them in place.

In the second form the pattern can be edited a little safer, and it makes backups of any modified files, by suffixing them with ".backup".

The third form is the way some versions of sed like it. (e.g. Mac OS X)

man sed for more information.

How to pass arguments to Shell Script through docker run

What I have is a script file that actually runs things. This scrip file might be relatively complicated. Let's call it "run_container". This script takes arguments from the command line:

run_container p1 p2 p3

A simple run_container might be:

echo "argc = ${#*}"
echo "argv = ${*}"

What I want to do is, after "dockering" this I would like to be able to startup this container with the parameters on the docker command line like this:

docker run image_name p1 p2 p3

and have the run_container script be run with p1 p2 p3 as the parameters.

This is my solution:


ADD run_container /
ENTRYPOINT ["/bin/bash", "-c", "/run_container \"$@\"", "--"]

Postgres DB Size Command

SELECT pg_size_pretty(pg_database_size('name of database'));

Will give you the total size of a particular database however I don't think you can do all databases within a server.

However you could do this...

db_size TEXT;
FOR r in
SELECT datname FROM pg_database
WHERE datistemplate = false
db_size:= (SELECT pg_size_pretty(pg_database_size(r.datname)));

RAISE NOTICE 'Database:% , Size:%', r.datname , db_size;


How do I format my oracle queries so the columns don't wrap?

set linesize 3000

set wrap off

set termout off

set pagesize 0 embedded on

set trimspool on

Try with all above values.

Visual Studio "Could not copy" .... during build

the .vhost.exe is a debugger process, so it appears that the process being debugged hasn't closed properly. Chances are you have a bug that's keeping it alive and are not stopping the debug process correctly - there are options to detach from the process when you click 'stop debugging' instead of actually killing the debugger so maybe you have that set.

But that's the problem - the file you're trying to copy over is locked (ie still being used) by the OS so its preventing the copy. Ensure that file is free and you'll be able to copy.

I just discovered why all ASP.Net websites are slow, and I am trying to work out what to do about it

After struggling with all available options, I ended up writing a JWT token based SessionStore provider (the session travels inside a cookie, and no backend storage is needed).


  • Drop-in replacement, no changes to your code are needed
  • Scale better than any other centralized store, as no session storage backend is needed.
  • Faster than any other session storage, as no data needs to be retrieved from any session storage
  • Consumes no server resources for session storage.
  • Default non-blocking implementation: concurrent request won't block each other and hold a lock on the session
  • Horizontally scale your application: because the session data travels with the request itself you can have multiple web heads without worrying about session sharing.

How to include duplicate keys in HashMap?

You can't have duplicate keys in a Map. You can rather create a Map<Key, List<Value>>, or if you can, use Guava's Multimap.

Multimap<Integer, String> multimap = ArrayListMultimap.create();
multimap.put(1, "rohit");
multimap.put(1, "jain");

System.out.println(multimap.get(1));  // Prints - [rohit, jain]

And then you can get the java.util.Map using the Multimap#asMap() method.

how to remove only one style property with jquery

You can also replace "-moz-user-select:none" with "-moz-user-select:inherit". This will inherit the style value from any parent style or from the default style if no parent style was defined.

How to select the first element of a set with JSTL?

You can use the EL 3.0 Stream API.


Be careful! The EL 3.0 Stream API was finalized before the Java 8 Stream API and it is different than that. They can't sunc both apis because it will break the backward compatibility.

How can I parse a local JSON file from assets folder into a ListView?

{ // json object node
    "formules": [ // json array formules
    { // json object 
      "formule": "Linear Motion", // string
      "url": "qp1"

What you are doing

  Context context = null; // context is null 
    try {
        String jsonLocation = AssetJSONFile("formules.json", context);

So change to

   try {
        String jsonLocation = AssetJSONFile("formules.json", CatList.this);

To parse

I believe you get the string from the assests folder.

String jsonLocation = AssetJSONFile("formules.json", context);
JSONObject jsonobject = new JSONObject(jsonLocation);
JSONArray jarray = (JSONArray) jsonobject.getJSONArray("formules");
for(int i=0;i<jarray.length();i++)
JSONObject jb =(JSONObject) jarray.get(i);
String formula = jb.getString("formule");
String url = jb.getString("url");
} catch (IOException e) {
} catch (JSONException e) {

Regex for 1 or 2 digits, optional non-alphanumeric, 2 known alphas


\d defines a number and {1,2} means 1 or two of the expression before, \W defines a non word character.

C++ Convert string (or char*) to wstring (or wchar_t*)

String to wstring

std::wstring Str2Wstr(const std::string& str)
    int size_needed = MultiByteToWideChar(CP_UTF8, 0, &str[0], (int)str.size(), NULL, 0);
    std::wstring wstrTo(size_needed, 0);
    MultiByteToWideChar(CP_UTF8, 0, &str[0], (int)str.size(), &wstrTo[0], size_needed);
    return wstrTo;

wstring to String

std::string Wstr2Str(const std::wstring& wstr)
    typedef std::codecvt_utf8<wchar_t> convert_typeX;
    std::wstring_convert<convert_typeX, wchar_t> converterX;
    return converterX.to_bytes(wstr);

How to change package name in flutter?

Updated You have to change the package name to your desired package name in these five location.

1.) src/profile/AndroidManifest.xml
2.) src/debug/AndroidManifest.xml
3.) src/main/AdroidManifest.xml
4.) build.gradle .
       defaultConfig {
5.) on "package"

last step is to run flutter clean

ResourceDictionary in a separate assembly

Resource-Only DLL is an option for you. But it is not required necessarily unless you want to modify resources without recompiling applications. Have just one common ResourceDictionary file is also an option. It depends how often you change resources and etc.

<ResourceDictionary Source="pack://application:,,,/

MyAssembly - Just assembly name without extension

FolderStructureInAssembly - If your resources are in a folde, specify folder structure

When you are doing this it's better to aware of siteOfOrigin as well.

WPF supports two authorities: application:/// and siteoforigin:///. The application:/// authority identifies application data files that are known at compile time, including resource and content files. The siteoforigin:/// authority identifies site of origin files. The scope of each authority is shown in the following figure.

enter image description here

AngularJS - Find Element with attribute

You haven't stated where you're looking for the element. If it's within the scope of a controller, it is possible, despite the chorus you'll hear about it not being the 'Angular Way'. The chorus is right, but sometimes, in the real world, it's unavoidable. (If you disagree, get in touch—I have a challenge for you.)

If you pass $element into a controller, like you would $scope, you can use its find() function. Note that, in the jQueryLite included in Angular, find() will only locate tags by name, not attribute. However, if you include the full-blown jQuery in your project, all the functionality of find() can be used, including finding by attribute.

So, for this HTML:

<div ng-controller='MyCtrl'>
        <div name='foo' class='myElementClass'>this one</div>

This AngularJS code should work:

angular.module('MyClient').controller('MyCtrl', [
    function ($scope, $element, $log) {

        // Find the element by its class attribute, within your controller's scope
        var myElements = $element.find('.myElementClass');

        // myElements is now an array of jQuery DOM elements

        if (myElements.length == 0) {
            // Not found. Are you sure you've included the full jQuery?
        } else {
            // There should only be one, and it will be element 0
            $log.debug(myElements[0].name); // "foo"


PackagesNotFoundError: The following packages are not available from current channels:

Conda itself provides a quite detailed guidance about installing non-conda packages. Details can be found here:

The basic idea is to use conda-forge. If it doesn't work, activate the environment and use pip.

Adding JPanel to JFrame

do it simply

public class Test{
    public Test(){
    }//end Test()

public void design(){
    JFame f = new JFrame();
    f.setSize(int w, int h);
    JPanel p = new JPanel(); 

public static void main(String[] args){
     EventQueue.invokeLater(new Runnable(){
     public void run(){
             new Test();
         }catch(Exception e){



How to store a list in a column of a database table

Simple answer: If, and only if, you're certain that the list will always be used as a list, then join the list together on your end with a character (such as '\0') that will not be used in the text ever, and store that. Then when you retrieve it, you can split by '\0'. There are of course other ways of going about this stuff, but those are dependent on your specific database vendor.

As an example, you can store JSON in a Postgres database. If your list is text, and you just want the list without further hassle, that's a reasonable compromise.

Others have ventured suggestions of serializing, but I don't really think that serializing is a good idea: Part of the neat thing about databases is that several programs written in different languages can talk to one another. And programs serialized using Java's format would not do all that well if a Lisp program wanted to load it.

If you want a good way to do this sort of thing there are usually array-or-similar types available. Postgres for instance, offers array as a type, and lets you store an array of text, if that's what you want, and there are similar tricks for MySql and MS SQL using JSON, and IBM's DB2 offer an array type as well (in their own helpful documentation). This would not be so common if there wasn't a need for this.

What you do lose by going that road is the notion of the list as a bunch of things in sequence. At least nominally, databases treat fields as single values. But if that's all you want, then you should go for it. It's a value judgement you have to make for yourself.

How to move columns in a MySQL table?

If empName is a VARCHAR(50) column:

ALTER TABLE Employees MODIFY COLUMN empName VARCHAR(50) AFTER department;


Per the comments, you can also do this:

ALTER TABLE Employees CHANGE COLUMN empName empName VARCHAR(50) AFTER department;

Note that the repetition of empName is deliberate. You have to tell MySQL that you want to keep the same column name.

You should be aware that both syntax versions are specific to MySQL. They won't work, for example, in PostgreSQL or many other DBMSs.

Another edit: As pointed out by @Luis Rossi in a comment, you need to completely specify the altered column definition just before the AFTER modifier. The above examples just have VARCHAR(50), but if you need other characteristics (such as NOT NULL or a default value) you need to include those as well. Consult the docs on ALTER TABLE for more info.

What is "android:allowBackup"?

It is privacy concern. It is recommended to disallow users to backup an app if it contains sensitive data. Having access to backup files (i.e. when android:allowBackup="true"), it is possible to modify/read the content of an app even on a non-rooted device.

Solution - use android:allowBackup="false" in the manifest file.

You can read this post to have more information: Hacking Android Apps Using Backup Techniques

How to remove the first and the last character of a string

You can do something like that :


This regex is a common way to have the same behaviour of the trim function used in many languages.

A possible implementation of trim function is :

function trim(string, char){
    if(!char) char = ' '; //space by default
    char = char.replace(/([()[{*+.$^\\|?])/g, '\\$1'); //escape char parameter if needed for regex syntax.
    var regex_1 = new RegExp("^" + char + "+", "g");
    var regex_2 = new RegExp(char + "+$", "g");
    return string.replace(regex_1, '').replace(regex_2, '');

Which will delete all / at the beginning and the end of the string. It handles cases like ///installers/services///

You can also simply do :

"/installers/".substring(1, string.length-1);

How do I convert csv file to rdd

A simplistic approach would be to have a way to preserve the header.

Let's say you have a file.csv like:

user, topic, hits
om,  scala, 120
daniel, spark, 80
3754978, spark, 1

We can define a header class that uses a parsed version of the first row:

class SimpleCSVHeader(header:Array[String]) extends Serializable {
  val index = header.zipWithIndex.toMap
  def apply(array:Array[String], key:String):String = array(index(key))

That we can use that header to address the data further down the road:

val csv = sc.textFile("file.csv")  // original file
val data = => line.split(",").map(elem => elem.trim)) //lines in rows
val header = new SimpleCSVHeader(data.take(1)(0)) // we build our header with the first line
val rows = data.filter(line => header(line,"user") != "user") // filter the header out
val users = => header(row,"user")
val usersByHits = => header(row,"user") -> header(row,"hits").toInt)

Note that the header is not much more than a simple map of a mnemonic to the array index. Pretty much all this could be done on the ordinal place of the element in the array, like user = row(0)

PS: Welcome to Scala :-)

How to get Latitude and Longitude of the mobile device in android?

Best way is

Add permission manifest file

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

Then you can get GPS location or if GPS location is not available then this function return NETWORK location

    public static Location getLocationWithCheckNetworkAndGPS(Context mContext) {
    LocationManager lm = (LocationManager)
    assert lm != null;
    isGpsEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
    isNetworkLocationEnabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

    Location networkLoacation = null, gpsLocation = null, finalLoc = null;
    if (isGpsEnabled)
        if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            return null;
        }gpsLocation = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
    if (isNetworkLocationEnabled)
        networkLoacation = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

    if (gpsLocation != null && networkLoacation != null) {

        //smaller the number more accurate result will
        if (gpsLocation.getAccuracy() > networkLoacation.getAccuracy())
            return finalLoc = networkLoacation;
            return finalLoc = gpsLocation;

    } else {

        if (gpsLocation != null) {
            return finalLoc = gpsLocation;
        } else if (networkLoacation != null) {
            return finalLoc = networkLoacation;
    return finalLoc;

SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

Changing the data type to text helped dataType: 'text'

I have check with JSONlint and my json format was proper. Still it was throwing error when I set dataType: 'json'

JSON Data: {"eventinvite":1,"groupcount":8,"totalMessagesUnread":0,"unreadmessages":{"378":0,"379":0,"380":0,"385":0,"390":0,"393":0,"413":0,"418":0}} 

Excel add one hour

This may help you as well. This is a conditional statement that will fill the cell with a default date if it is empty but will subtract one hour if it is a valid date/time and put it into the cell.


You can also substitute TIME with DATE to add or subtract a date or time.

How to automatically generate getters and setters in Android Studio

Using Alt+ Insert for Windows or Command+ N for Mac in the editor, you may easily generate getter and setter methods for any fields of your class. This has the same effect as using the Menu Bar -> Code -> Generate...

enter image description here

and then using shift or control button, select all the variables you need to add getters and setters

Horizontal ListView in Android?

As per Android Documentation RecyclerView is the new way to organize the items in listview and to be displayed horizontally


  1. Since by using Recyclerview Adapter, ViewHolder pattern is automatically implemented
  2. Animation is easy to perform
  3. Many more features

More Information about RecyclerView:



Just add the below block to make the ListView to horizontal from vertical


LinearLayoutManager layoutManager= new LinearLayoutManager(this,LinearLayoutManager.HORIZONTAL, false);
mRecyclerView = (RecyclerView) findViewById(;

How to query data out of the box using Spring data JPA by both Sort and Pageable?

In my case, to use Pageable and Sorting at the same time I used like below. In this case I took all elements using pagination and sorting by id by descending order:

modelRepository.findAll(PageRequest.of(page, 10,"id").descending()))

Like above based on your requirements you can sort data with 2 columns as well.

ExecuteNonQuery doesn't return results

From MSDN: SqlCommand.ExecuteNonQuery Method

You can use the ExecuteNonQuery to perform catalog operations (for example, querying the structure of a database or creating database objects such as tables), or to change the data in a database without using a DataSet by executing UPDATE, INSERT, or DELETE statements.

Although the ExecuteNonQuery returns no rows, any output parameters or return values mapped to parameters are populated with data.

For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. When a trigger exists on a table being inserted or updated, the return value includes the number of rows affected by both the insert or update operation and the number of rows affected by the trigger or triggers. For all other types of statements, the return value is -1. If a rollback occurs, the return value is also -1.

You are using SELECT query, thus you get -1

Email Address Validation in Android on EditText

Use this method to validate the EMAIL :-

 public static boolean isEditTextContainEmail(EditText argEditText) {

            try {
                Pattern pattern = Pattern.compile("^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$");
                Matcher matcher = pattern.matcher(argEditText.getText());
                return matcher.matches();
            } catch (Exception e) {
                return false;

Let me know if you have any queries ?

Where do I mark a lambda expression async?

And for those of you using an anonymous expression:

await Task.Run(async () =>
   SQLLiteUtils slu = new SQLiteUtils();
   await slu.DeleteGroupAsync(groupname);

How to resolve git status "Unmerged paths:"?

Another way of dealing with this situation if your files ARE already checked in, and your files have been merged (but not committed, so the merge conflicts are inserted into the file) is to run:

git reset

This will switch to HEAD, and tell git to forget any merge conflicts, and leave the working directory as is. Then you can edit the files in question (search for the "Updated upstream" notices). Once you've dealt with the conflicts, you can run

git add -p

which will allow you to interactively select which changes you want to add to the index. Once the index looks good (git diff --cached), you can commit, and then

git reset --hard

to destroy all the unwanted changes in your working directory.

How to create an infinite loop in Windows batch file?

Here is an example of using the loop:

echo off


set /P M=Input text to encode md5, press ENTER to exit: 
if %M%==%M1% goto end

echo.|set /p ="%M%" | openssl md5

set M1=%M%
Goto begin

This is the simple batch i use when i need to encrypt any message into md5 hash on Windows(openssl required), and the program would loyally repeat itself except given Ctrl+C or empty input.

How to add a jar in External Libraries in android studio


  1. Add libs folder in your project(Where build.gradle is located). E.g. app
  2. Move .jar into libs
  3. Add implementation files('libs/<name>.jar') into build.gradle. It is the same as UI Add as library do

JavaScript, Node.js: is Array.forEach asynchronous?

Although Array.forEach is not asynchronous, you can get asynchronous "end result". Example below:

function delayFunction(x) {
    return new Promise(
        (resolve) => setTimeout(() => resolve(x), 1000)

[1, 2, 3].forEach(async(x) => {
    console.log(await delayFunction(x));

How to add font-awesome to Angular 2 + CLI project

After Angular 2.0 final release, the structure of the Angular2 CLI project has been changed — you don't need any vendor files, no system.js — only webpack. So you do:

  1. npm install font-awesome --save

  2. In the angular-cli.json file locate the styles[] array and add font-awesome references directory here, like below:

    "apps": [
          "root": "src",
          "outDir": "dist",
          "styles": [
              "../node_modules/font-awesome/css/font-awesome.css" // -here webpack will automatically build a link css element out of this!?

    In more recent versions of Angular, use the angular.json file instead, without the ../. For example, use "node_modules/font-awesome/css/font-awesome.css".

  3. Place some font-awesome icons in any html file you want:

    <i class="fa fa-american-sign-language-interpreting fa-5x" aria-hidden="true"> </i>
  4. Stop the application Ctrl + c then re-run the app using ng serve because the watchers are only for the src folder and angular-cli.json is not observed for changes.

  5. Enjoy your awesome icons!

Escaping regex string

You can use re.escape():

re.escape(string) Return string with all non-alphanumerics backslashed; this is useful if you want to match an arbitrary literal string that may have regular expression metacharacters in it.

>>> import re
>>> re.escape('^a.*$')

If you are using a Python version < 3.7, this will escape non-alphanumerics that are not part of regular expression syntax as well.

If you are using a Python version < 3.7 but >= 3.3, this will escape non-alphanumerics that are not part of regular expression syntax, except for specifically underscore (_).

How do I modify fields inside the new PostgreSQL JSON datatype?

You can also increment keys atomically within jsonb like this:

UPDATE users SET counters = counters || CONCAT('{"bar":', COALESCE(counters->>'bar','0')::int + 1, '}')::jsonb WHERE id = 1;

SELECT * FROM users;

 id |    counters
  1 | {"bar": 1}

Undefined key -> assumes starting value of 0.

For more detailed explanation, see my answer here:

What is the correct XPath for choosing attributes that contain "foo"?

For the code above... //*[contains(@prop,'foo')]

C++ template constructor

As far as I understand, it's impossible to have it (because it would conflict with the default constructor - am I right?)

You are wrong. It doesn't conflict in any way. You just can't call it ever.

How to write into a file in PHP?

fwrite() is a smidgen faster and file_put_contents() is just a wrapper around those three methods anyway, so you would lose the overhead. Article


The file_put_contents writes a string to a file.

This function follows these rules when accessing a file.If FILE_USE_INCLUDE_PATH is set, check the include path for a copy of filename Create the file if it does not exist then Open the file and Lock the file if LOCK_EX is set and If FILE_APPEND is set, move to the end of the file. Otherwise, clear the file content Write the data into the file and Close the file and release any locks. This function returns the number of the character written into the file on success, or FALSE on failure.


The fwrite writes to an open file.The function will stop at the end of the file or when it reaches the specified length, whichever comes first.This function returns the number of bytes written or FALSE on failure.

How to trigger a file download when clicking an HTML button or JavaScript

Another way of doing in case you have a complex URL such as file.doc?foo=bar&jon=doe is to add hidden field inside the form

<form method="get" action="file.doc">
  <input type="hidden" name="foo" value="bar" />
  <input type="hidden" name="john" value="doe" />
  <button type="submit">Download Now</button>

inspired on @Cfreak answer which is not complete

Return Max Value of range that is determined by an Index & Match lookup

You don't need an index match formula. You can use this array formula. You have to press CTL + SHIFT + ENTER after you enter the formula.



enter image description here


I had added an additional line to the application's manifest file, which is android:installLocation="preferExternal". by using this line it forces to install the app to the external storage. see the example below,

<manifest xmlns:android=""
    android:installLocation="preferExternal" >

Reset Windows Activation/Remove license key

On Windows XP -

  1. Reboot into "Safe mode with Command Prompt"
  2. Type "explorer" in the command prompt that comes up and push [Enter]
  3. Click on Start>Run, and type the following :

    rundll32.exe syssetup,SetupOobeBnk

Reboot, and login as normal.

This will reset the 30 day timer for activation back to 30 days so you can enter in the key normally.

Unable to compile class for JSP: The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files

From the JIRA knowledge base:


Workflow actions may be inaccessible

  1. JIRA may throw exceptions on screen
  2. One or both of the following conditions may exist:

The following appears in the atlassian-jira.log:

     2007-12-06 10:55:05,327 http-8080-Processor20 ERROR [500ErrorPage] 
     Exception caught in500 page Unable to compile class for JSP
    org.apache.jasper.JasperException: Unable to compile class for JSP
   at org.apache.jasper.JspCompilationContext.compile(
   at org.apache.jasper.servlet.JspServletWrapper.service(



The Tomcat container caches .java and .class files generated by the JSP parser they are used by the web application. Sometimes these get corrupted or cannot be found. This may occur after a patch or upgrade that contains modifications to JSPs.


1.Delete the contents of the /work folder if using standalone JIRA or /work if using EAR/WAR installation . 2. Verify the user running the JIRA application process has Read/Write permission to the /work directory. 3. Restart the JIRA application container to rebuild the files.

How to add default signature in Outlook

Need to add a reference to Microsoft.Outlook. it is in Project references, from the visual basic window top menu.

Private Sub sendemail_Click()

  Dim OutlookApp As Outlook.Application
  Dim OutlookMail As Outlook.MailItem

  Set OutlookApp = New Outlook.Application
  Set OutlookMail = OutlookApp.CreateItem(olMailItem)

  With OutlookMail
    .To = email
    .Subject = "subject"

    Dim wdDoc As Object     ' Word.Document
    Dim wdRange As Object   ' Word.Range
    Set wdDoc = .GetInspector.WordEditor
    Set wdRange = wdDoc.Range(0, 0) ' Create Range at character position 0 with length of 0 character s.

    ' if you need rtl:
    wdRange.Paragraphs.ReadingOrder = 0 ' 0 is rtl , 1 is ltr

    wdRange.InsertAfter "mytext"
  End With

End Sub

How to use LINQ Distinct() with multiple fields

Answering the headline of the question (what attracted people here) and ignoring that the example used anonymous types....

This solution will also work for non-anonymous types. It should not be needed for anonymous types.

Helper class:

/// <summary>
/// Allow IEqualityComparer to be configured within a lambda expression.
/// From
/// </summary>
/// <typeparam name="T"></typeparam>
public class LambdaEqualityComparer<T> : IEqualityComparer<T>
    readonly Func<T, T, bool> _comparer;
    readonly Func<T, int> _hash;

    /// <summary>
    /// Simplest constructor, provide a conversion to string for type T to use as a comparison key (GetHashCode() and Equals().
    ///, user "orip"
    /// </summary>
    /// <param name="toString"></param>
    public LambdaEqualityComparer(Func<T, string> toString)
        : this((t1, t2) => toString(t1) == toString(t2), t => toString(t).GetHashCode())

    /// <summary>
    /// Constructor.  Assumes T.GetHashCode() is accurate.
    /// </summary>
    /// <param name="comparer"></param>
    public LambdaEqualityComparer(Func<T, T, bool> comparer)
        : this(comparer, t => t.GetHashCode())

    /// <summary>
    /// Constructor, provide a equality comparer and a hash.
    /// </summary>
    /// <param name="comparer"></param>
    /// <param name="hash"></param>
    public LambdaEqualityComparer(Func<T, T, bool> comparer, Func<T, int> hash)
        _comparer = comparer;
        _hash = hash;

    public bool Equals(T x, T y)
        return _comparer(x, y);

    public int GetHashCode(T obj)
        return _hash(obj);

Simplest usage:

List<Product> products = duplicatedProducts.Distinct(
    new LambdaEqualityComparer<Product>(p =>

The simplest (but not that efficient) usage is to map to a string representation so that custom hashing is avoided. Equal strings already have equal hash codes.

Wrap a delegate in an IEqualityComparer

Pycharm/Python OpenCV and CV2 install error

When I was facing this issue I used to install OpenCV in pycharm installed package panel where we can find under the settings tab. Search "OpenCV-python" and install it in the installed package panel of right interpreter.

How can I programmatically get the MAC address of an iphone

Now iOS 7 devices – are always returning a MAC address of 02:00:00:00:00:00.

So better use [UIDevice identifierForVendor].

so better to call this method to get app specific unique key

Category will more suitable

import "UIDevice+Identifier.h"

- (NSString *) identifierForVendor1
    if ([[UIDevice currentDevice] respondsToSelector:@selector(identifierForVendor)]) {
        return [[[UIDevice currentDevice] identifierForVendor] UUIDString];
    return @"";

Now call above method to get unique address

NSString *like_UDID=[NSString stringWithFormat:@"%@",
                [[UIDevice currentDevice] identifierForVendor1]];


Unable to add window -- token android.os.BinderProxy is not valid; is your activity running?

I faced exactly the same issue. Calling '(!isFinishing())' prevented the crash, but it could not display the 'alert' message.

Then I tried making calling function 'static', where alert is displayed. After that, no crash happened and message is also getting displayed.

For ex:

public static void connect_failure() {      
        Log.i(FW_UPD_APP, "Connect failed");

        new AlertDialog.Builder(MyActivity)
        .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) { 
                  //do nothing

How do I display image in Alert/confirm box in Javascript?

You can emojis!

$('#test').on('click', () => {
    alert(' Build is too fast');

jQuery: select all elements of a given class, except for a particular Id

Or take the .not() method


How to add one column into existing SQL Table

alter table table_name add field_name (size);

alter table arnicsc add place number(10);

How do I convert this list of dictionaries to a csv file?

this is when you have one dictionary list:

import csv
with open('names.csv', 'w') as csvfile:
    fieldnames = ['first_name', 'last_name']
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
    writer.writerow({'first_name': 'Baked', 'last_name': 'Beans'})

How to check object is nil or not in swift?

func isObjectValid(someObject: Any?) -> Any? {
    if someObject is String {
        if let someObject = someObject as? String {
            return someObject
        }else {
            return ""
    }else if someObject is Array<Any> {
        if let someObject = someObject as? Array<Any> {
            return someObject
        }else {
            return []
    }else if someObject is Dictionary<AnyHashable, Any> {
        if let someObject = someObject as? Dictionary<String, Any> {
            return someObject
        }else {
            return [:]
    }else if someObject is Data {
        if let someObject = someObject as? Data {
            return someObject
        }else {
            return Data()
    }else if someObject is NSNumber {
        if let someObject = someObject as? NSNumber{
            return someObject
        }else {
            return NSNumber.init(booleanLiteral: false)
    }else if someObject is UIImage {
        if let someObject = someObject as? UIImage {
            return someObject
        }else {
            return UIImage()
    else {
        return "InValid Object"

This function checks any kind of object and return's default value of the kind of object, if object is invalid.

How to get the query string by javascript?

Here's the method I use...

function Querystring() {
    var q =, qs = {};
    if (q.length) {
        var keys = q.split("&"), k, kv, key, val, v;
        for (k = keys.length; k--; ) {
            kv = keys[k].split("=");
            key = kv[0];
            val = decodeURIComponent(kv[1]);
            if (qs[key] === undefined) {
                qs[key] = val;
            } else {
                v = qs[key];
                if (v.constructor != Array) {
                    qs[key] = [];
    return qs;

It returns an object of strings and arrays and seems to work quite well. (Strings for single keys, arrays for the same key with multiple values.)

Error: Uncaught SyntaxError: Unexpected token <

try to replace the text/javascript to text/html then save the note and reload browser then bring it back to text/javascript.. I don't know but for unknown reason this one works with me.. I am searching and copy-pasting and I just accidentally undo what I am typing then boom kablooey it worked 0.O by the way I am just noob.. sorry I just thought it could help though..

In Python, how do you convert seconds since epoch to a `datetime` object?

datetime.datetime.fromtimestamp will do, if you know the time zone, you could produce the same output as with time.gmtime

>>> datetime.datetime.fromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 11, 19, 54)


>>> datetime.datetime.utcfromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 10, 19, 54)

What is the default scope of a method in Java?

Anything defined as package private can be accessed by the class itself, other classes within the same package, but not outside of the package, and not by sub-classes.

See this page for a handy table of access level modifiers...

Create normal zip file programmatically

You can now use the ZipArchive class (System.IO.Compression.ZipArchive), available from .NET 4.5

You have to add System.IO.Compression as a reference.

Example: Generating a zip of PDF files

using (var fileStream = new FileStream(@"C:\temp\", FileMode.CreateNew))
    using (var archive = new ZipArchive(fileStream, ZipArchiveMode.Create, true))
        foreach (var creditNumber in creditNumbers)
            var pdfBytes = GeneratePdf(creditNumber);
            var fileName = "credit_" + creditNumber + ".pdf";
            var zipArchiveEntry = archive.CreateEntry(fileName, CompressionLevel.Fastest);
            using (var zipStream = zipArchiveEntry.Open())
                zipStream.Write(pdfBytes, 0, pdfBytes.Length);

can't multiply sequence by non-int of type 'float'

In this line:

fund = fund * (1 + 0.01 * growthRates) + depositPerYear

growthRates is a sequence ([3,4,5,0,3]). You can't multiply that sequence by a float (0.1). It looks like what you wanted to put there was i.

Incidentally, i is not a great name for that variable. Consider something more descriptive, like growthRate or rate.

Server unable to read htaccess file, denying access to be safe

I had same problem on Fedora, and found that problem was selinux. to test that it is problem run command: sudo setenforce 0

Otherwise or change in file /etc/sysconfig/selinux


or add rules to selinux to allow http access

How to send an email with Gmail as provider using Python?

Not directly related but still worth pointing out is that my package tries to make sending gmail messages really quick and painless. It also tries to maintain a list of errors and tries to point to the solution immediately.

It would literally only need this code to do exactly what you wrote:

import yagmail
yag = yagmail.SMTP('[email protected]')
yag.send('[email protected]', 'Why,Oh why!')

Or a one liner:

yagmail.SMTP('[email protected]').send('[email protected]', 'Why,Oh why!')

For the package/installation please look at git or pip, available for both Python 2 and 3.

Stop/Close webcam stream which is opened by navigator.mediaDevices.getUserMedia

Try method below:

var mediaStream = null;
            audio: true,
            video: true
        function (stream) {
            mediaStream = stream;
            mediaStream.stop = function () {
                this.getAudioTracks().forEach(function (track) {
                this.getVideoTracks().forEach(function (track) { //in case... :)
             * Rest of your code.....
             * */

    * somewhere insdie your code you call
    * */

HTML: Image won't display?

I found that skipping the quotation marks "" around the file and location name displayed the image... I am doing this on MacBook....

How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?

Time Zone Handling

I just want to clarify, even though this has been commented so future people don't miss this very important distinction.

DateTime.strptime("1318996912",'%s') # => Wed, 19 Oct 2011 04:01:52 +0000

displays a return value in UTC and requires the seconds to be a String and outputs a UTC Time object, whereas # => 2011-10-19 00:01:52 -0400

displays a return value in the LOCAL time zone, normally requires a FixNum argument, but the Time object itself is still in UTC even though the display is not.

So even though I passed the same integer to both methods, I seemingly two different results because of how the class' #to_s method works. However, as @Eero had to remind me twice of: == DateTime.strptime("1318996912",'%s') # => true

An equality comparison between the two return values still returns true. Again, this is because the values are basically the same (although different classes, the #== method takes care of this for you), but the #to_s method prints drastically different strings. Although, if we look at the strings, we can see they are indeed the same time, just printed in different time zones.

Method Argument Clarification

The docs also say "If a numeric argument is given, the result is in local time." which makes sense, but was a little confusing to me because they don't give any examples of non-integer arguments in the docs. So, for some non-integer argument examples:"1318996912")
TypeError: can't convert String into an exact number

you can't use a String argument, but you can use a Time argument into and it will return the result in the time zone of the argument:,11,1,15,25,0, "+09:00"))
=> 2007-11-01 15:25:00 +0900


After a discussion with @AdamEberlin on his answer, I decided to publish slightly changed benchmarks to make everything as equal as possible. Also, I never want to have to build these again so this is as good a place as any to save them. ~ 2.8x faster

09:10:58-watsw018:~$ ruby -v
ruby 2.3.7p456 (2018-03-28 revision 63024) [universal.x86_64-darwin18]
09:11:00-watsw018:~$ irb
irb(main):001:0> require 'benchmark'
=> true
irb(main):002:0> require 'date'
=> true
irb(main):004:0* format = '%s'
=> "%s"
irb(main):005:0> times = ['1318996912', '1318496913']
=> ["1318996912", "1318496913"]
irb(main):006:0> int_times =
=> [1318996912, 1318496913]
irb(main):008:0* datetime_from_strptime = DateTime.strptime(times.first, format)
=> #<DateTime: 2011-10-19T04:01:52+00:00 ((2455854j,14512s,0n),+0s,2299161j)>
irb(main):009:0> datetime_from_time =
=> #<DateTime: 2011-10-19T00:01:52-04:00 ((2455854j,14512s,0n),-14400s,2299161j)>
irb(main):011:0* datetime_from_strptime === datetime_from_time
=> true
irb(main):013:0* Benchmark.measure do
irb(main):014:1*   100_000.times {
irb(main):015:2*     times.each do |i|
irb(main):016:3*       DateTime.strptime(i, format)
irb(main):017:3>     end
irb(main):018:2>   }
irb(main):019:1> end
=> #<Benchmark::Tms:0x00007fbdc18f0d28 @label="", @real=0.8680500000045868, @cstime=0.0, @cutime=0.0, @stime=0.009999999999999998, @utime=0.86, @total=0.87>
irb(main):021:0* Benchmark.measure do
irb(main):022:1*   100_000.times {
irb(main):023:2*     int_times.each do |i|
irb(main):025:3>     end
irb(main):026:2>   }
irb(main):027:1> end
=> #<Benchmark::Tms:0x00007fbdc3108be0 @label="", @real=0.33059399999910966, @cstime=0.0, @cutime=0.0, @stime=0.0, @utime=0.32000000000000006, @total=0.32000000000000006>

****edited to not be completely and totally incorrect in every way****

****added benchmarks****

Auto number column in SharePoint list

As stated, all objects in sharepoint contain some sort of unique identifier (often an integer based counter for list items, and GUIDs for lists).

That said, there is also a feature available at called "Unique Column Policy", designed to add an other column with a unique value. A complete writeup is available at!8F5DEA8AEA9E6FBB!293.entry

Find the 2nd largest element in an array with minimum number of comparisons

I suppose, follow the "optimal algorithm uses n+log n-2 comparisons" from above, the code that I came up with that doesn't use binary tree to store the value would be the following:

During each recursive call, the array size is cut in half.

So the number of comparison is:

1st iteration: n/2 comparisons

2nd iteration: n/4 comparisons

3rd iteration: n/8 comparisons

... Up to log n iterations?

Hence, total => n - 1 comparisons?

function findSecondLargestInArray(array) {
    let winner = [];
    if (array.length === 2) {
        if (array[0] < array[1]) {
            return array[0];
        } else {
            return array[1];
    for (let i = 1; i <= Math.floor(array.length / 2); i++) {
        if (array[2 * i - 1] > array[2 * i - 2]) {
            winner.push(array[2 * i - 1]);
        } else {
            winner.push(array[2 * i - 2]);
    return findSecondLargestInArray(winner);

Assuming array contain 2^n number of numbers.

If there are 6 numbers, then 3 numbers will move to the next level, which is not right.

Need like 8 numbers => 4 number => 2 number => 1 number => 2^n number of number

Best way to unselect a <select> in jQuery?

It's a been a while since asked, and I haven't tested this on older browsers but it seems to me a much simpler answer is


.val() works for select as well

How to replace master branch in Git, entirely, from another branch?

What about using git branch -m to rename the master branch to another one, then rename seotweaks branch to master? Something like this:

git branch -m master old-master
git branch -m seotweaks master
git push -f origin master

This might remove commits in origin master, please check your origin master before running git push -f origin master.

Compiler error: "class, interface, or enum expected"

class, interface, or enum expected

The above error is even possible when import statement is miss spelled. A proper statement is "import;"

If by mistake while code writing/editing it is miss written like "t;"

compiler will show "class, interface, or enum expected"

How to convert string to float?

Unfortunately, there is no way to do this easily. Every solution has its drawbacks.

  1. Use atof() or strtof() directly: this is what most people will tell you to do and it will work most of the time. However, if the program sets a locale or it uses a library that sets the locale (for instance, a graphics library that displays localised menus) and the user has their locale set to a language where the decimal separator is not . (such as fr_FR where the separator is ,) these functions will stop parsing at the . and you will stil get 4.0.

  2. Use atof() or strtof() but change the locale; it's a matter of calling setlocale(LC_ALL|~LC_NUMERIC, ""); before any call to atof() or the likes. The problem with setlocale is that it will be global to the process and you might interfer with the rest of the program. Note that you might query the current locale with setlocale() and restore it after you're done.

  3. Write your own float parsing routine. This might be quite quick if you do not need advanced features such as exponent parsing or hexadecimal floats.

Also, note that the value 4.08 cannot be represented exactly as a float; the actual value you will get is 4.0799999237060546875.

How to call window.alert("message"); from C#?

You can try this:

Hope it works for you..

`private void validateUserEntry()
    // Checks the value of the text.
    if(serverName.Text.Length == 0)
    // Initializes the variables to pass to the MessageBox.Show method.
    string message = "You did not enter a server name. Cancel this operation?";
    string caption = "Error Detected in Input";
    MessageBoxButtons buttons = MessageBoxButtons.YesNo;
    DialogResult result;

    // Displays the MessageBox.
    result = MessageBox.Show(message, caption, buttons);
    if (result == System.Windows.Forms.DialogResult.Yes)
     // Closes the parent form.

How do I simulate a hover with a touch in touch enabled browsers?

Further Improved Solution

First I went with the Rich Bradshaw's approach, but then problems started to appear. By doing the e.preventDefault() on 'touchstart' event, the page no longer scrolls and, neither the long press is able to fire the options menu nor double click zoom is able to finish executing.

A solution could be finding out which event is being called and just e.preventDefault() in the later one, 'touchend'. Since scroll's 'touchmove' comes before 'touchend' it stays as by default, and 'click' is also prevented since it comes afterwords in the event chain applied to mobile, like so:

// Binding to the '.static_parent' ensuring dynamic ajaxified content
$('.static_parent').on('touchstart touchend', '.link', function (e) {

    // If event is 'touchend' then...
    if (e.type == 'touchend') {
        // Ensuring we event prevent default in all major browsers
        e.preventDefault ? e.preventDefault() : e.returnValue = false;

    // Add class responsible for :hover effect

But then, when options menu appears, it no longer fires 'touchend' responsible for toggling off the class, and next time the hover behavior will be the other way around, totally mixed up.

A solution then would be, again, conditionally finding out which event we're in, or just doing separate ones, and use addClass() and removeClass() respectively on 'touchstart' and 'touchend', ensuring it always starts and ends by respectively adding and removing instead of conditionally deciding on it. To finish we will also bind the removing callback to the 'focusout' event type, staying responsible for clearing any link's hover class that might stay on and never revisited again, like so:

$('.static_parent').on('touchstart', '.link', function (e) {

$('.static_parent').on('touchend focusout', '.link', function (e) {
    // Think double click zoom still fails here
    e.preventDefault ? e.preventDefault() : e.returnValue = false;

Atention: Some bugs still occur in the two previous solutions and, also think (not tested), double click zoom still fails too.

Tidy and Hopefully Bug Free (not :)) Javascript Solution

Now, for a second, cleaner, tidier and responsive, approach just using javascript (no mix between .hover class and pseudo :hover) and from where you could call directly your ajax behavior on the universal (mobile and desktop) 'click' event, I've found a pretty well answered question from which I finally understood how I could mix touch and mouse events together without several event callbacks inevitably changing each other's ones up the event chain. Here's how:

$('.static_parent').on('touchstart mouseenter', '.link', function (e) {

$('.static_parent').on('mouseleave touchmove click', '.link', function (e) {

    // As it's the chain's last event we only prevent it from making HTTP request
    if (e.type == 'click') {
        e.preventDefault ? e.preventDefault() : e.returnValue = false;

        // Ajax behavior here!

How to make a Qt Widget grow with the window size?

The accepted answer (its image) is wrong, at least now in QT5. Instead you should assign a layout to the root object/widget (pointing to the aforementioned image, it should be the MainWindow instead of centralWidget). Also note that you must have at least one QObject created beneath it for this to work. Do this and your ui will become responsive to window resizing.

Post values from a multiple select

You need to add a name attribute.

Since this is a multiple select, at the HTTP level, the client just sends multiple name/value pairs with the same name, you can observe this yourself if you use a form with method="GET": someurl?something=1&something=2&something=3.

In the case of PHP, Ruby, and some other library/frameworks out there, you would need to add square braces ([]) at the end of the name. The frameworks will parse that string and wil present it in some easy to use format, like an array.

Apart from manually parsing the request there's no language/framework/library-agnostic way of accessing multiple values, because they all have different APIs

For PHP you can use:

<select name="something[]" id="inscompSelected" multiple="multiple" class="lstSelected">

How are POST and GET variables handled in Python?

Python is only a language, to get GET and POST data, you need a web framework or toolkit written in Python. Django is one, as Charlie points out, the cgi and urllib standard modules are others. Also available are Turbogears, Pylons, CherryPy,, mod_python, fastcgi, etc, etc.

In Django, your view functions receive a request argument which has request.GET and request.POST. Other frameworks will do it differently.

How do I change selected value of select2 dropdown with JqGrid?

You have two options - as @PanPipes answer states you can do the following.


This is an acceptable solution only if one doesn't have any custom actions binded to the change event. The solution I use in this situation is to trigger a select2 specific event which updates the select2 displayed selection.


print memory address of Python variable

There is no way to get the memory address of a value in Python 2.7 in general. In Jython or PyPy, the implementation doesn't even know your value's address (and there's not even a guarantee that it will stay in the same place—e.g., the garbage collector is allowed to move it around if it wants).

However, if you only care about CPython, id is already returning the address. If the only issue is how to format that integer in a certain way… it's the same as formatting any integer:

>>> hex(33)
>>> '{:#010x}'.format(33) # 32-bit
>>> '{:#018x}'.format(33) # 64-bit

… and so on.

However, there's almost never a good reason for this. If you actually need the address of an object, it's presumably to pass it to ctypes or similar, in which case you should use ctypes.addressof or similar.

How can I enable or disable the GPS programmatically on Android?

This is the best solution provided by Google Developers. Simply call this method in onResume of onCreate after initializing GoogleApiClient.

private void updateMarkers() {
    if (mMap == null) {

    if (mLocationPermissionGranted) {
        // Get the businesses and other points of interest located
        // nearest to the device's current location.
         mGoogleApiClient = new GoogleApiClient.Builder(this)
        LocationRequest locationRequest = LocationRequest.create();
        locationRequest.setFastestInterval(10000 / 2);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder().addLocationRequest(locationRequest);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest
        PendingResult<LocationSettingsResult> resultPendingResult = LocationServices

        resultPendingResult.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            public void onResult(@NonNull LocationSettingsResult locationSettingsResult) {
                final Status status = locationSettingsResult.getStatus();
                final LocationSettingsStates locationSettingsStates = locationSettingsResult.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        // All location settings are satisfied. The client can
                        // initialize location requests here.

                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied, but this can be fixed
                        // by showing the user a dialog.

                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.

                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way
                        // to fix the settings so we won't show the dialog.



        PendingResult<PlaceLikelihoodBuffer> result = Places.PlaceDetectionApi
                .getCurrentPlace(mGoogleApiClient, null);
        result.setResultCallback(new ResultCallback<PlaceLikelihoodBuffer>() {
            public void onResult(@NonNull PlaceLikelihoodBuffer likelyPlaces) {
                for (PlaceLikelihood placeLikelihood : likelyPlaces) {
                    // Add a marker for each place near the device's current location, with an
                    // info window showing place information.
                    String attributions = (String) placeLikelihood.getPlace().getAttributions();
                    String snippet = (String) placeLikelihood.getPlace().getAddress();
                    if (attributions != null) {
                        snippet = snippet + "\n" + attributions;

                    mMap.addMarker(new MarkerOptions()
                            .title((String) placeLikelihood.getPlace().getName())
                // Release the place likelihood buffer.
    } else {
        mMap.addMarker(new MarkerOptions()

Note : This line of code automatic open the dialog box if Location is not on. This piece of line is used in Google Map also


Flask Python Buttons

The appropriate way for doing this:

def index():
    if form.validate_on_submit():
        if 'download' in request.form:
            pass # do something
        elif 'watch' in request.form:
            pass # do something else

Put watch and download buttons into your template:

<input type="submit" name="download" value="Download">
<input type="submit" name="watch" value="Watch">

Load json from local file with http.get() in angular 2

For Angular 5+ only preform steps 1 and 4

In order to access your file locally in Angular 2+ you should do the following (4 steps):

[1] Inside your assets folder create a .json file, example: data.json

[2] Go to your angular.cli.json (angular.json in Angular 6+) inside your project and inside the assets array put another object (after the package.json object) like this:

{ "glob": "data.json", "input": "./", "output": "./assets/" }

full example from angular.cli.json

"apps": [
      "root": "src",
      "outDir": "dist",
      "assets": [
        { "glob": "package.json", "input": "../", "output": "./assets/" },
        { "glob": "data.json", "input": "./", "output": "./assets/" }

Remember, data.json is just the example file we've previously added in the assets folder (you can name your file whatever you want to)

[3] Try to access your file via localhost. It should be visible within this address, http://localhost:your_port/assets/data.json

If it's not visible then you've done something incorrectly. Make sure you can access it by typing it in the URL field in your browser before proceeding to step #4.

[4] Now preform a GET request to retrieve your .json file (you've got your full path .json URL and it should be simple)

 constructor(private http: HttpClient) {}
        // Make the HTTP request:
                 .subscribe(data => console.log(data));

How to make an introduction page with Doxygen

Add any file in the documentation which will include your content, for example toc.h:

@ mainpage Manual SDK
@ section pageTOC Content
  -# @ref Description
  -# @ref License
  -# @ref Item

And in your Doxyfile:

INPUT = toc.h \

Example (in Russian):

Frequency table for a single variable

You can use list comprehension on a dataframe to count frequencies of the columns as such

[my_series[c].value_counts() for c in list(my_series.select_dtypes(include=['O']).columns)]



Selects just the categorical data


Turns the columns from above into a list

[my_series[c].value_counts() for c in list(my_series.select_dtypes(include=['O']).columns)] 

Iterates through the list above and applies value_counts() to each of the columns

How to write a:hover in inline CSS?

I agree with shadow. You could use the onmouseover and onmouseout event to change the CSS via JavaScript.

And don't say people need to have JavaScript activated. It's only a style issue, so it doesn't matter if there are some visitors without JavaScript ;) Although most of Web 2.0 works with JavaScript. See Facebook for example (lots of JavaScript) or Myspace.

How to check cordova android version of a cordova/phonegap project?

For getting all the info about the cordova package use this command:

npm info cordova

String MinLength and MaxLength validation don't work ( mvc)

MaxLength is used for the Entity Framework to decide how large to make a string value field when it creates the database.

From MSDN:

Specifies the maximum length of array or string data allowed in a property.

StringLength is a data annotation that will be used for validation of user input.

From MSDN:

Specifies the minimum and maximum length of characters that are allowed in a data field.

Non Customized

Use [String Length]

[RegularExpression(@"^.{3,}$", ErrorMessage = "Minimum 3 characters required")]
[Required(ErrorMessage = "Required")]
[StringLength(30, MinimumLength = 3, ErrorMessage = "Maximum 30 characters")]

30 is the Max Length
Minimum length = 3

Customized StringLengthAttribute Class

public class MyStringLengthAttribute : StringLengthAttribute
    public MyStringLengthAttribute(int maximumLength)
        : base(maximumLength)

    public override bool IsValid(object value)
        string val = Convert.ToString(value);
        if (val.Length < base.MinimumLength)
            base.ErrorMessage = "Minimum length should be 3";
        if (val.Length > base.MaximumLength)
            base.ErrorMessage = "Maximum length should be 6";
        return base.IsValid(value);

public class MyViewModel
    [MyStringLength(6, MinimumLength = 3)]
    public String MyProperty { get; set; }

Forms authentication timeout vs sessionState timeout

For anyone stumbling across this question refer to this documentation from MS - it has really good details regarding FormsAuthentication Timeout setting.

This doc explains in detail about the comment bmode is making in the Accepted Answer - about the Persistent Cookie (Session vs Expires)

Using custom std::set comparator

You are using a function where as you should use a functor (a class that overloads the () operator so it can be called like a function).

struct lex_compare {
    bool operator() (const int64_t& lhs, const int64_t& rhs) const {
        stringstream s1, s2;
        s1 << lhs;
        s2 << rhs;
        return s1.str() < s2.str();

You then use the class name as the type parameter

set<int64_t, lex_compare> s;

If you want to avoid the functor boilerplate code you can also use a function pointer (assuming lex_compare is a function).

set<int64_t, bool(*)(const int64_t& lhs, const int64_t& rhs)> s(&lex_compare);

How do you kill a Thread in Java?

In Java threads are not killed, but the stopping of a thread is done in a cooperative way. The thread is asked to terminate and the thread can then shutdown gracefully.

Often a volatile boolean field is used which the thread periodically checks and terminates when it is set to the corresponding value.

I would not use a boolean to check whether the thread should terminate. If you use volatile as a field modifier, this will work reliable, but if your code becomes more complex, for instead uses other blocking methods inside the while loop, it might happen, that your code will not terminate at all or at least takes longer as you might want.

Certain blocking library methods support interruption.

Every thread has already a boolean flag interrupted status and you should make use of it. It can be implemented like this:

public void run() {
   try {
      while (!interrupted()) {
         // ...
   } catch (InterruptedException consumed)
      /* Allow thread to exit */

public void cancel() { interrupt(); }

Source code adapted from Java Concurrency in Practice. Since the cancel() method is public you can let another thread invoke this method as you wanted.

Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models?

(Edit: Forget my previous babble...)

Ok, there might be situations where you would go either to the model or to some other url... But I don't really think this belongs in the model, the view (or maybe the model) sounds more apropriate.

About the routes, as far as I know the routes is for the actions in controllers (wich usually "magically" uses a view), not directly to views. The controller should handle all requests, the view should present the results and the model should handle the data and serve it to the view or controller. I've heard a lot of people here talking about routes to models (to the point I'm allmost starting to beleave it), but as I understand it: routes goes to controllers. Of course a lot of controllers are controllers for one model and is often called <modelname>sController (e.g. "UsersController" is the controller of the model "User").

If you find yourself writing nasty amounts of logic in a view, try to move the logic somewhere more appropriate; request and internal communication logic probably belongs in the controller, data related logic may be placed in the model (but not display logic, which includes link tags etc.) and logic that is purely display related would be placed in a helper.

How to get the position of a character in Python?


Perhaps you'd like to have a look at the documentation to find out what the difference between the two is.

Reading and writing environment variables in Python?

First things first :) reading books is an excellent approach to problem solving; it's the difference between band-aid fixes and long-term investments in solving problems. Never miss an opportunity to learn. :D

You might choose to interpret the 1 as a number, but environment variables don't care. They just pass around strings:

   The argument envp is an array of character pointers to null-
   terminated strings. These strings shall constitute the
   environment for the new process image. The envp array is
   terminated by a null pointer.

(From environ(3posix).)

You access environment variables in python using the os.environ dictionary-like object:

>>> import os
>>> os.environ["HOME"]
>>> os.environ["PATH"]
>>> os.environ["PATH"] = os.environ["PATH"] + ":/silly/"
>>> os.environ["PATH"]

Convert XML String to Object

Another way with an Advanced xsd to c# classes generation Tools : This tool is very handy and powerfull. It has a lot more customisation than the xsd.exe tool from Visual Studio. Xsd2Code++ can be customised to use Lists or Arrays and supports large schemas with a lot of Import statements.

Note of some features,

  • Generates business objects from XSD Schema or XML file to flexible C# or Visual Basic code.
  • Support Framework 2.0 to 4.x
  • Support strong typed collection (List, ObservableCollection, MyCustomCollection).
  • Support automatic properties.
  • Generate XML read and write methods (serialization/deserialization).
  • Databinding support (WPF, Xamarin).
  • WCF (DataMember attribute).
  • XML Encoding support (UTF-8/32, ASCII, Unicode, Custom).
  • Camel case / Pascal Case support.
  • restriction support ([StringLengthAttribute=true/false], [RegularExpressionAttribute=true/false], [RangeAttribute=true/false]).
  • Support large and complex XSD file.
  • Support of DotNet Core & standard

Stashing only staged changes in git - is it possible?

Stashing just the index (staged changes) in Git is more difficult than it should be. I've found @Joe's answer to work well, and turned a minor variation of it into this alias:

stash-index = "!f() { \
  git stash push --quiet --keep-index -m \"temp for stash-index\" && \
  git stash push \"$@\" && \
  git stash pop --quiet stash@{1} && \
  git stash show -p | git apply -R; }; f"

It pushes both the staged and unstaged changes into a temporary stash, leaving the staged changes alone. It then pushes the staged changes into the stash, which is the stash we want to keep. Arguments passed to the alias, such as --message "whatever" will be added to this stash command. Finally, it pops the temporary stash to restore the original state and remove the temporary stash, and then finally "removes" the stashed changes from the working directory via a reverse patch application.

For the opposite problem of stashing just the unstaged changes (alias stash-working) see this answer.

Failed to resolve: in IntelliJ Idea with gradle

I had the same problem and it resolved by disabling Gradle's offline mode although I could not remember when I did disable it!

Here's the solution:

How to disable Gradle 'offline mode' in android studio? [duplicate]

Diff files present in two different directories

diff can not only compare two files, it can, by using the -r option, walk entire directory trees, recursively checking differences between subdirectories and files that occur at comparable points in each tree.

$ man diff


-r  --recursive
        Recursively compare any subdirectories found.


Why does corrcoef return a matrix?

corrcoef returns the normalised covariance matrix.

The covariance matrix is the matrix

Cov( X, X )    Cov( X, Y )

Cov( Y, X )    Cov( Y, Y )

Normalised, this will yield the matrix:

Corr( X, X )    Corr( X, Y )

Corr( Y, X )    Corr( Y, Y )

correlation1[0, 0 ] is the correlation between Strategy1Returns and itself, which must be 1. You just want correlation1[ 0, 1 ].

Connection string using Windows Authentication

For the correct solution after many hours:

  1. Open the configuration file
  2. Change the connection string with the following

<add name="umbracoDbDSN" connectionString="data source=YOUR_SERVER_NAME;database=nrc;Integrated Security=SSPI;persist security info=True;" providerName="System.Data.SqlClient" />

  1. Change the YOUR_SERVER_NAME with your current server name and save
  2. Open the IIS Manager
  3. Find the name of the application pool that the website or web application is using
  4. Right-click and choose Advanced settings
  5. From Advanced settings under Process Model change the Identity to Custom account and add your Server Admin details, please see the attached images:

enter image description here

Hope this will help.

ASP.NET Web Site or ASP.NET Web Application?

Web Application project model

  • Provides the same Web project semantics as Visual Studio .NET Web projects. Has a project file (structure based on project files). Build model - all code in the project is compiled into a single assembly. Supports both IIS and the built-in ASP.NET Development Server. Supports all the features of Visual Studio 2005 (refactoring, generics, etc.) and of ASP.NET (master pages, membership and login, site navigation, themes, etc). Using FrontPage Server Extensions (FPSE) are no longer a requirement.

Web Site project model

  • No project file (Based on file system).
  • New compilation model.
  • Dynamic compilation and working on pages without building entire site on each page view.
  • Supports both IIS and the built-in ASP.NET Development Server.
  • Each page has it's own assembly.
  • Defferent code model.

How to set Linux environment variables with Ansible

Here's a quick local task to permanently set key/values on /etc/environment (which is system-wide, all users):

- name: populate /etc/environment
    dest: "/etc/environment"
    state: present
    regexp: "^{{ item.key }}="
    line: "{{ item.key }}={{ item.value}}"
  with_items: "{{ os_environment }}"

and the vars for it:

    value : websec.prod_settings  
    value : admin

and, yes, if you ssh out and back in, env shows the new environment variables.

How to distinguish mouse "click" and "drag"

If just to filter out the drag case, do it like this:

var moved = false;
  .mousedown(function() {moved = false;})
  .mousemove(function() {moved = true;})
  .mouseup(function(event) {
    if (!moved) {
        // clicked without moving mouse

how to show only even or odd rows in sql server 2008?

Try this :

odd :

select * from( 
SELECT col1, col2, ROW_NUMBER() OVER(ORDER BY col1 DESC) AS 'RowNumber', 
FROM table1
) d where (RowNumber % 2) = 1 

even :

select * from( 
SELECT col1, col2, ROW_NUMBER() OVER(ORDER BY col1 DESC) AS 'RowNumber', 
FROM table1
) d where (RowNumber % 2) = 0

UTC Date/Time String to Timezone

How about:

$timezone = new DateTimeZone('UTC');
$date = new DateTime('2011-04-21 13:14', $timezone);
echo $date->format;

How can I autoplay a video using the new embed code style for Youtube?

You are using a wrong url for youtube auto play this url display youtube id as wholeJW5meKfy3fY&autoplay=1 which youtube rejects to play. we have to pass autoplay variable to youtube, therefore you have to use ? instead of & so your url will be and your final iframe will be like that.

<iframe src="" width="960" height="447" frameborder="0" allowfullscreen></iframe>

Can I use an HTML input type "date" to collect only a year?

I try with this, no modifications on the css.

$(function() {_x000D_
    changeYear: true,_x000D_
    showButtonPanel: true,_x000D_
    dateFormat: 'yy',_x000D_
    onClose: function(dateText, inst) {_x000D_
      var year = $("#ui-datepicker-div .ui-datepicker-year :selected").val();_x000D_
      $(this).datepicker('setDate', new Date(year, 1));_x000D_
  $("#datepicker").focus(function() {_x000D_
<script src=""></script>_x000D_
<script src=""></script>_x000D_
<p>Date: <input type="text" id="datepicker" /></p>

Example code jsfiddle

How to switch activity without animation in Android?

The line in the theme style works fine, yet that replaces the animation with a white screen. Especially on a slower phone - it is really annoying. So, if you want an instant transition - you could use this in the theme style:

<item name="android:windowAnimationStyle">@null</item>
<item name="android:windowDisablePreview">true</item>

Remove attribute "checked" of checkbox

Both of these should work:

$("#captureImage").prop('checked', false);



... you can try both together.

Proxies with Python 'Requests' module

8 years late. But I like:

import os
import requests

os.environ['HTTP_PROXY'] = os.environ['http_proxy'] = 'http://http-connect-proxy:3128/'
os.environ['HTTPS_PROXY'] = os.environ['https_proxy'] = 'http://http-connect-proxy:3128/'
os.environ['NO_PROXY'] = os.environ['no_proxy'] = ',localhost,.local'

r = requests.get('')  # , verify=False

How to include quotes in a string

Use escape characters for example this code:

var message = "I want to learn \"c#\"";

will output:

I want to learn "c#"

How to check if a string is a number?

#include <stdio.h>
#include <string.h>
char isNumber(char *text)
    int j;
    j = strlen(text);
        if(text[j] > 47 && text[j] < 58)

        return 0;
    return 1;
int main(){
    char tmp[16];
    scanf("%s", tmp);

        return printf("is a number\n");

    return printf("is not a number\n");

You can also check its stringfied value, which could also work with non Ascii

char isNumber(char *text)
    int j;
    j = strlen(text);
        if(text[j] >= '0' && text[j] <= '9')

        return 0;
    return 1;

Simple timeout in java

Use this line of code:


It will sleep for 1 second.

How do you revert to a specific tag in Git?

Git tags are just pointers to the commit. So you use them the same way as you do HEAD, branch names or commit sha hashes. You can use tags with any git command that accepts commit/revision arguments. You can try it with git rev-parse tagname to display the commit it points to.

In your case you have at least these two alternatives:

  1. Reset the current branch to specific tag:

    git reset --hard tagname
  2. Generate revert commit on top to get you to the state of the tag:

    git revert tag

This might introduce some conflicts if you have merge commits though.

VBA - Run Time Error 1004 'Application Defined or Object Defined Error'

Your cells object is not fully qualified. You need to add a DOT before the cells object. For example

With Worksheets("Cable Cards")
    .Range(.Cells(RangeStartRow, RangeStartColumn), _
           .Cells(RangeEndRow, RangeEndColumn)).PasteSpecial xlValues

Similarly, fully qualify all your Cells object.

What is a constant reference? (not a reference to a constant)

The clearest answer. Does “X& const x” make any sense?

No, it is nonsense

To find out what the above declaration means, read it right-to-left: “x is a const reference to a X”. But that is redundant — references are always const, in the sense that you can never reseat a reference to make it refer to a different object. Never. With or without the const.

In other words, “X& const x” is functionally equivalent to “X& x”. Since you’re gaining nothing by adding the const after the &, you shouldn’t add it: it will confuse people — the const will make some people think that the X is const, as if you had said “const X& x”.

How to trim a file extension from a String in JavaScript?

I like this one because it is a one liner which isn't too hard to read:

filename.substring(0, filename.lastIndexOf('.')) || filename

Adding space/padding to a UILabel

In Swift 3

best and simple way

class UILabelPadded: UILabel {
     override func drawText(in rect: CGRect) {
     let insets = UIEdgeInsets.init(top: 0, left: 5, bottom: 0, right: 5)
     super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))


How to get values of selected items in CheckBoxList with foreach in ASP.NET C#?

Just in case you want to store the selected values in single column seperated by , then you can use below approach

string selectedItems = String.Join(",", CBLGold.Items.OfType<ListItem>().Where(r => r.Selected).Select(r => r.Value));

if you want to store Text not values then Change the r.Value to r.Text

Drag and drop menuitems

jQuery UI draggable and droppable are the two plugins I would use to achieve this effect. As for the insertion marker, I would investigate modifying the div (or container) element that was about to have content dropped into it. It should be possible to modify the border in some way or add a JavaScript/jQuery listener that listens for the hover (element about to be dropped) event and modifies the border or adds an image of the insertion marker in the right place.

How do I divide so I get a decimal value?

You can do like,

int a = 3;
int b = 2;
int quotient = a / b;
int remainder = a % b;

To get quotient in real numbers

System.out.println((double) a / b);

To get quotient in integer numbers

System.out.println("Quotient: " + quotient);
System.out.println("Remainder: " + remainder);

To get quotient in real number such that one number after decimal

System.out.println(a / b + "." + a % b * 10 / b);

Note: In the last method it will not round the number up after the decimal.

How to upload file to server with HTTP POST multipart/form-data?

For people searching for 403 forbidden issue while trying to upload in multipart form the below might help as there is a case depending on the server configuration that you will get MULTIPART_STRICT_ERROR "!@eq 0" due to incorrect MultipartFormDataContent headers. Please note that both imagetag/filename variables include quotations (\") eg filename="\"myfile.png\"" .

    MultipartFormDataContent form = new MultipartFormDataContent();
    ByteArrayContent imageContent = new ByteArrayContent(fileBytes, 0, fileBytes.Length);
    imageContent.Headers.TryAddWithoutValidation("Content-Disposition", "form-data; name="+imagetag+"; filename="+filename);
    imageContent.Headers.TryAddWithoutValidation("Content-Type", "image / png");
    form.Add(imageContent, imagetag, filename);

How to dynamically add elements to String array?

Arrays in Java have a defined size, you cannot change it later by adding or removing elements (you can read some basics here).

Instead, use a List:

ArrayList<String> mylist = new ArrayList<String>();
mylist.add(mystring); //this adds an element to the list.

Of course, if you know beforehand how many strings you are going to put in your array, you can create an array of that size and set the elements by using the correct position:

String[] myarray = new String[numberofstrings];
myarray[23] = string24; //this sets the 24'th (first index is 0) element to string24.

How do I change file permissions in Ubuntu

Add -R for recursive:

sudo chmod -R 666 /var/www

Remove Trailing Spaces and Update in Columns in SQL Server

If you are using SQL Server (starting with vNext) or Azure SQL Database then you can use the below query.

SELECT TRIM(ColumnName) from TableName;

For other SQL SERVER Database you can use the below query.

SELECT LTRIM(RTRIM(ColumnName)) from TableName

LTRIM - Removes spaces from the left

example: select LTRIM(' test ') as trim = 'test '

RTRIM - Removes spaces from the right

example: select RTRIM(' test ') as trim = ' test'

How do you read from stdin?

Here's from Learning Python:

import sys
data = sys.stdin.readlines()
print "Counted", len(data), "lines."

On Unix, you could test it by doing something like:

% cat | python 
Counted 3 lines.

On Windows or DOS, you'd do:

C:\> type | python 
Counted 3 lines.

How to install mechanize for Python 2.7?

using pip:

pip install mechanize

or download the mechanize distribution archive, open it, and run:

python install

How can you get the Manifest Version number from the App's (Layout) XML variables?

There is not a way to directly get the version out, but there are two work-arounds that could be done.

  1. The version could be stored in a resource string, and placed into the manifest by:

    <manifest xmlns:android=""
         android:versionName="@string/version" android:versionCode="20">
  2. One could create a custom view, and place it into the XML. The view would use this to assign the name:

    context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionName;

Either of these solutions would allow for placing the version name in XML. Unfortunately there isn't a nice simple solution, like android.R.string.version or something like that.

Error inflating class

Well So I was trying to fix this error. And none worked for me. I was not able to figure out solution. Scenario:

I was just going to made a Navigation Drawer Project inside Android Studio 2.1.2 And when I try to change the default Android icon in nav_header_main.xml I was getting some weird errors. I figured out that I was droping my PNG logo into the ...\app\src\main\res\drawable-21. When I try to put my PNG logo in ...\app\src\main\res\drawable bam! All weird errors go away.

Following are some of stack trace when I was putting PNG into drawable-21 folder:

08-17 17:29:56.237 6644-6678/myAppName  E/dalvikvm: Could not find class 'android.util.ArrayMap', referenced from method
08-17 17:30:01.674 6644-6644/myAppName E/AndroidRuntime: FATAL EXCEPTION: main
                                                                         java.lang.RuntimeException: Unable to start activity ComponentInfo{myAppName.MainActivity}: android.view.InflateException: Binary XML file line #16: Error inflating class <unknown>
                                                                             at android.os.Handler.dispatchMessage(
                                                                             at android.os.Looper.loop(
                                                                             at java.lang.reflect.Method.invokeNative(Native Method)
                                                                             at java.lang.reflect.Method.invoke(
                                                                             at dalvik.system.NativeStart.main(Native Method)
                                                                          Caused by: android.view.InflateException: Binary XML file line #16: Error inflating class <unknown>
                                                                             at android.view.LayoutInflater.createView(
                                                                             at android.view.LayoutInflater.createViewFromTag(
                                                                             at android.view.LayoutInflater.rInflate(
                                                                             at android.view.LayoutInflater.inflate(
                                                                             at android.view.LayoutInflater.inflate(
                                                                             at android.view.LayoutInflater.inflate(
                                                                             at edu.uswat.fwd82.findmedoc.MainActivity.onCreate(
                                                                             at android.os.Handler.dispatchMessage( 
                                                                             at android.os.Looper.loop( 
                                                                             at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                             at java.lang.reflect.Method.invoke( 
                                                                             at dalvik.system.NativeStart.main(Native Method) 
                                                                          Caused by: java.lang.reflect.InvocationTargetException
                                                                             at java.lang.reflect.Constructor.constructNative(Native Method)
                                                                             at java.lang.reflect.Constructor.newInstance(
                                                                             at android.view.LayoutInflater.createView(
                                                                             at android.view.LayoutInflater.createViewFromTag( 
                                                                             at android.view.LayoutInflater.rInflate( 
                                                                             at android.view.LayoutInflater.inflate( 
                                                                             at android.view.LayoutInflater.inflate( 
                                                                             at android.view.LayoutInflater.inflate( 
                                                                             at edu.uswat.fwd82.findmedoc.MainActivity.onCreate( 
                                                                             at android.os.Handler.dispatchMessage( 
                                                                             at android.os.Looper.loop( 
                                                                             at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                             at java.lang.reflect.Method.invoke( 
                                                                             at dalvik.system.NativeStart.main(Native Method) 
                                                                          Caused by: android.view.InflateException: Binary XML file line #14: Error inflating class ImageView
                                                                             at android.view.LayoutInflater.createViewFromTag(
                                                                             at android.view.LayoutInflater.rInflate(
                                                                             at android.view.LayoutInflater.inflate(
                                                                             at android.view.LayoutInflater.inflate(
at java.lang.reflect.Constructor.constructNative(Native Method) 
at java.lang.reflect.Constructor.newInstance( 
at android.view.LayoutInflater.createView( 
                                                                             at android.view.LayoutInflater.createViewFromTag( 
                                                                             at android.view.LayoutInflater.rInflate( 
                                                                             at android.view.LayoutInflater.inflate( 
                                                                             at android.view.LayoutInflater.inflate( 
                                                                             at android.view.LayoutInflater.inflate( 
                                                                             at edu.uswat.fwd82.findmedoc.MainActivity.onCreate( 
                                                                             at android.os.Handler.dispatchMessage( 
                                                                             at android.os.Looper.loop( 
                                                                             at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                             at java.lang.reflect.Method.invoke( 
                                                                             at dalvik.system.NativeStart.main(Native Method) 
                                                                          Caused by: java.lang.NullPointerException
                                                                             at android.content.res.ResourcesEx.getThemeDrawable(
                                                                             at android.content.res.ResourcesEx.loadDrawable(
                                                                             at android.content.res.TypedArray.getDrawable(
                                                                             at android.widget.ImageView.<init>(
                                                                            at android.view.LayoutInflater.createViewFromTag(

As you can see the above Stack Trace include: at at

Laravel 4: how to run a raw SQL?

Actually, Laravel 4 does have a table rename function in Illuminate/Database/Schema/Builder.php, it's just undocumented at the moment: Schema::rename($from, $to);.

What is the lifetime of a static variable in a C++ function?

The lifetime of function static variables begins the first time[0] the program flow encounters the declaration and it ends at program termination. This means that the run-time must perform some book keeping in order to destruct it only if it was actually constructed.

Additionally, since the standard says that the destructors of static objects must run in the reverse order of the completion of their construction[1], and the order of construction may depend on the specific program run, the order of construction must be taken into account.


struct emitter {
    string str;
    emitter(const string& s) : str(s) { cout << "Created " << str << endl; }
    ~emitter() { cout << "Destroyed " << str << endl; }

void foo(bool skip_first) 
    if (!skip_first)
        static emitter a("in if");
    static emitter b("in foo");

int main(int argc, char*[])
    foo(argc != 2);
    if (argc == 3)


Created in foo
Destroyed in foo

C:>sample.exe 1
Created in if
Created in foo
Destroyed in foo
Destroyed in if

C:>sample.exe 1 2
Created in foo
Created in if
Destroyed in if
Destroyed in foo

[0] Since C++98[2] has no reference to multiple threads how this will be behave in a multi-threaded environment is unspecified, and can be problematic as Roddy mentions.

[1] C++98 section [basic.start.term]

[2] In C++11 statics are initialized in a thread safe way, this is also known as Magic Statics.

How to declare empty list and then add string in scala?

In your case I use: val dm = ListBuffer[String]() and val dk = ListBuffer[Map[String,anyRef]]()

PHP - Get bool to echo false when false

Try converting your boolean to an integer?

 echo (int)$bool_val;

How to include !important in jquery

For those times when you need to use jquery to set !important properties, here is a plugin I build that will allow you to do so.

$.fn.important = function(key, value) {
    var q = Object.assign({},
    q[key] = `${value} !important`;
    $(this).css("cssText", Object.entries(q).filter(x => x[1]).map(([k, v]) => (`${k}: ${v}`)).join(';'));

$('div').important('color', 'red');

How to add comments into a Xaml file in WPF?

You cannot put comments inside UWP XAML tags. Your syntax is right.


<!-- Cool comment -->


    <!-- Cool comment -->

What does "Content-type: application/json; charset=utf-8" really mean?

To substantiate @deceze's claim that the default JSON encoding is UTF-8...

From IETF RFC4627:

JSON text SHALL be encoded in Unicode. The default encoding is UTF-8.

Since the first two characters of a JSON text will always be ASCII characters [RFC0020], it is possible to determine whether an octet stream is UTF-8, UTF-16 (BE or LE), or UTF-32 (BE or LE) by looking at the pattern of nulls in the first four octets.

      00 00 00 xx  UTF-32BE
      00 xx 00 xx  UTF-16BE
      xx 00 00 00  UTF-32LE
      xx 00 xx 00  UTF-16LE
      xx xx xx xx  UTF-8

How to subtract date/time in JavaScript?

You can use getTime() method to convert the Date to the number of milliseconds since January 1, 1970. Then you can easy do any arithmetic operations with the dates. Of course you can convert the number back to the Date with setTime(). See here an example.

C#: calling a button event handler method without actually clicking the button

Simply call:

btnTest_Click(null, null);

Just make sure you aren't trying to use either of those params in the function.

install apt-get on linux Red Hat server


rpm -ivh apt-0.5.15lorg3.1-4.el4.rf.i386.rpm


rpm -Uvh rpmforge-release-0.3.4-1.el4.rf.i386.rpm

maybe some URL is broken,please research it. Enjoy~~

How to sum up elements of a C++ vector?

Prasoon has already offered up a host of different (and good) ways to do this, none of which need repeating here. I'd like to suggest an alternative approach for speed however.

If you're going to be doing this quite a bit, you may want to consider "sub-classing" your vector so that a sum of elements is maintained separately (not actually sub-classing vector which is iffy due to the lack of a virtual destructor - I'm talking more of a class that contains the sum and a vector within it, has-a rather than is-a, and provides the vector-like methods).

For an empty vector, the sum is set to zero. On every insertion to the vector, add the element being inserted to the sum. On every deletion, subtract it. Basically, anything that can change the underlying vector is intercepted to ensure the sum is kept consistent.

That way, you have a very efficient O(1) method for "calculating" the sum at any point in time (just return the sum currently calculated). Insertion and deletion will take slightly longer as you adjust the total and you should take this performance hit into consideration.

Vectors where the sum is needed more often than the vector is changed are the ones likely to benefit from this scheme, since the cost of calculating the sum is amortised over all accesses. Obviously, if you only need the sum every hour and the vector is changing three thousand times a second, it won't be suitable.

Something like this would suffice:

class UberVector:
    private Vector<int> vec
    private int sum

    public UberVector():
        vec = new Vector<int>()
        sum = 0

    public getSum():
        return sum

    public add (int val):
        rc = vec.add (val)
        if rc == OK:
            sum = sum + val
        return rc

    public delindex (int idx):
        val = 0
        if idx >= 0 and idx < vec.size:
            val = vec[idx]
        rc =  vec.delindex (idx)
        if rc == OK:
            sum = sum - val
        return rc

Obviously, that's pseudo-code and you may want to have a little more functionality, but it shows the basic concept.

How to generate .angular-cli.json file in Angular Cli?

In angular.json you can insert all css and js file in your template. Other ways, you can use from Style.css in src folder for load stylesheets.

@import "../src/fonts/font-awesome/css/font-awesome.min.css";
@import "../src/css/bootstrap.min.css";
@import "../src/css/now-ui-kit.css";
@import "../src/css/plugins/owl.carousel.css";
@import "../src/css/plugins/owl.theme.default.min.css";
@import "../src/css/main.css";

Why is the Java main method static?

The static key word in the main method is used because there isn't any instantiation that take place in the main method. But object is constructed rather than invocation as a result we use the static key word in the main method. In jvm context memory is created when class loads into it.And all static members are present in that memory. if we make the main static now it will be in memory and can be accessible to jvm (class.main(..)) so we can call the main method with out need of even need for heap been created.

What does "make oldconfig" do exactly in the Linux kernel makefile?

From this page:

Make oldconfig takes the .config and runs it through the rules of the Kconfig files and produces a .config which is consistant with the Kconfig rules. If there are CONFIG values which are missing, the make oldconfig will ask for them.

If the .config is already consistant with the rules found in Kconfig, then make oldconfig is essentially a no-op.

If you were to run make oldconfig, and then run make oldconfig a second time, the second time won't cause any additional changes to be made.

How to convert Integer to int?

Java converts Integer to int and back automatically (unless you are still with Java 1.4).

How to load URL in UIWebView in Swift?

UIWebView loadRequest: Create NSURLRequest using NSURL object, then passing the request to uiwebview it will load the requested URL into the web view.

 override func viewDidLoad() {
     // Do any additional setup after loading the view, typically from a nib.
     let url = NSURL (string: "");
     let requestObj = NSURLRequest(URL: url!);

For more reference:

How to use EOF to run through a text file in C?

You should check the EOF after reading from file.

fscanf_s                   // read from file
while(condition)           // check EOF
   fscanf_s               // read from file

Push local Git repo to new remote including all branches and tags

Below command will push all the branches(including the ones which you have never checked-out but present in your git repo, you can see them by git branch -a)

git push origin '*:*'

NOTE: This command comes handy when you are migrating version control service(i.e migrating from Gitlab to GitHub)

Easiest way to use SVG in Android?

Rather than adding libraries which increases your apk size, I will suggest you to convert Svg to drawable using . and add vectorDrawables.useSupportLibrary = true in gradle,

Need help rounding to 2 decimal places

The problem will be that you cannot represent 0.575 exactly as a binary floating point number (eg a double). Though I don't know exactly it seems that the representation closest is probably just a bit lower and so when rounding it uses the true representation and rounds down.

If you want to avoid this problem then use a more appropriate data type. decimal will do what you want:

Math.Round(0.575M, 2, MidpointRounding.AwayFromZero)

Result: 0.58

The reason that 0.75 does the right thing is that it is easy to represent in binary floating point since it is simple 1/2 + 1/4 (ie 2^-1 +2^-2). In general any finite sum of powers of two can be represented in binary floating point. Exceptions are when your powers of 2 span too great a range (eg 2^100+2 is not exactly representable).

Edit to add:

Formatting doubles for output in C# might be of interest in terms of understanding why its so hard to understand that 0.575 is not really 0.575. The DoubleConverter in the accepted answer will show that 0.575 as an Exact String is 0.5749999999999999555910790149937383830547332763671875 You can see from this why rounding give 0.57.

How to convert Java String to JSON Object

The string that you pass to the constructor JSONObject has to be escaped with quote():

public static java.lang.String quote(java.lang.String string)

Your code would now be:

JSONObject jsonObj = new JSONObject.quote(jsonString.toString());

Zero an array in C code

Using memset:

int something[20];
memset(something, 0, 20 * sizeof(int));

Change R default library path using .libPaths in fails to work

On Ubuntu, the recommended way of changing the default library path for a user, is to set the R_LIBS_USER variable in the ~/.Renviron file.

touch ~/.Renviron
echo "R_LIBS_USER=/custom/path/in/absolute/form" >> ~/.Renviron

Hadoop/Hive : Loading data from .csv on a local machine

Let me work you through the following simple steps:


First, create a table on hive using the field names in your csv file. Lets say for example, your csv file contains three fields (id, name, salary) and you want to create a table in hive called "staff". Use the below code to create the table in hive.

hive> CREATE TABLE Staff (id int, name string, salary double) row format delimited fields terminated by ',';

Second, now that your table is created in hive, let us load the data in your csv file to the "staff" table on hive.

hive>  LOAD DATA LOCAL INPATH '/home/yourcsvfile.csv' OVERWRITE INTO TABLE Staff;

Lastly, display the contents of your "Staff" table on hive to check if the data were successfully loaded

hive> SELECT * FROM Staff;


'adb' is not recognized as an internal or external command, operable program or batch file

It seems that Avast antivirus detects adb.exe as a virus and adds it to it chest

What is the difference between resource and endpoint?

According is a resource a "general" place of storage of the given entity - e.g. /customers/30654/orders, whereas an endpoint is the concrete action (HTTP Method) over the given resource. So one resource can have multiple endpoints.

Converting Object to JSON and JSON to Object in PHP, (library like Gson for Java)

This should do the trick!

// convert object => json
$json = json_encode($myObject);

// convert json => object
$obj = json_decode($json);

Here's an example

$foo = new StdClass();
$foo->hello = "world";
$foo->bar = "baz";

$json = json_encode($foo);
echo $json;
//=> {"hello":"world","bar":"baz"}

// stdClass Object
// (
//   [hello] => world
//   [bar] => baz
// )

If you want the output as an Array instead of an Object, pass true to json_decode

print_r(json_decode($json, true));
// Array
// (
//   [hello] => world
//   [bar] => baz
// )    

More about json_encode()

See also: json_decode()

How do I get textual contents from BLOB in Oracle SQL

SQL Developer provides this functionality too :

Double click the results grid cell, and click edit :

enter image description here

Then on top-right part of the pop up , "View As Text" (You can even see images..)

enter image description here

And that's it!

enter image description here

Android check internet connection

All official methods only tells whether a device is open for network or not,
If your device is connected to Wifi but Wifi is not connected to internet then these method will fail (Which happen many time), No inbuilt network detection method will tell about this scenario, so created Async Callback class which will return in onConnectionSuccess and onConnectionFail

new CheckNetworkConnection(this, new CheckNetworkConnection.OnConnectionCallback() {

    public void onConnectionSuccess() {
        Toast.makeText(context, "onSuccess()", toast.LENGTH_SHORT).show();

    public void onConnectionFail(String msg) {
        Toast.makeText(context, "onFail()", toast.LENGTH_SHORT).show();

Network Call from async Task

public class CheckNetworkConnection extends AsyncTask < Void, Void, Boolean > {
    private OnConnectionCallback onConnectionCallback;
    private Context context;

    public CheckNetworkConnection(Context con, OnConnectionCallback onConnectionCallback) {
        this.onConnectionCallback = onConnectionCallback;
        this.context = con;

    protected void onPreExecute() {

    protected Boolean doInBackground(Void...params) {
        if (context == null)
            return false;

        boolean isConnected = new NetWorkInfoUtility().isNetWorkAvailableNow(context);
        return isConnected;

    protected void onPostExecute(Boolean b) {

        if (b) {
        } else {
            String msg = "No Internet Connection";
            if (context == null)
                msg = "Context is null";


    public interface OnConnectionCallback {
        void onConnectionSuccess();

        void onConnectionFail(String errorMsg);

Actual Class which will ping to server

class NetWorkInfoUtility {

    public boolean isWifiEnable() {
        return isWifiEnable;

    public void setIsWifiEnable(boolean isWifiEnable) {
        this.isWifiEnable = isWifiEnable;

    public boolean isMobileNetworkAvailable() {
        return isMobileNetworkAvailable;

    public void setIsMobileNetworkAvailable(boolean isMobileNetworkAvailable) {
        this.isMobileNetworkAvailable = isMobileNetworkAvailable;

    private boolean isWifiEnable = false;
    private boolean isMobileNetworkAvailable = false;

    public boolean isNetWorkAvailableNow(Context context) {
        boolean isNetworkAvailable = false;

        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);


        if (isWifiEnable() || isMobileNetworkAvailable()) {
            /*Sometime wifi is connected but service provider never connected to internet
            so cross check one more time*/
            if (isOnline())
                isNetworkAvailable = true;

        return isNetworkAvailable;

    public boolean isOnline() {
        /*Just to check Time delay*/
        long t = Calendar.getInstance().getTimeInMillis();

        Runtime runtime = Runtime.getRuntime();
        try {
            /*Pinging to Google server*/
            Process ipProcess = runtime.exec("/system/bin/ping -c 1");
            int exitValue = ipProcess.waitFor();
            return (exitValue == 0);
        } catch (IOException e) {
        } catch (InterruptedException e) {
        } finally {
            long t2 = Calendar.getInstance().getTimeInMillis();
            Log.i("NetWork check Time", (t2 - t) + "");
        return false;

Tensorflow import error: No module named 'tensorflow'

In Anaconda Prompt (Anaconda 3), Type: conda install tensorflow command

This fix my issue in my Anaconda with Python 3.8.


How to update and order by using ms sql

UPDATE messages SET 
WHERE ID in (SELECT TOP (10) Id FROM Table WHERE status=0 ORDER BY priority DESC);

Download image from the site in .NET/C#

You can use this code

using (WebClient client = new WebClient()) {
                    Stream stream = client.OpenRead(imgUrl);
                    if (stream != null) {
                        Bitmap bitmap = new Bitmap(stream);
                        ImageFormat imageFormat = ImageFormat.Jpeg;
                        if (bitmap.RawFormat.Equals(ImageFormat.Png)) {
                            imageFormat = ImageFormat.Png;
                        else if (bitmap.RawFormat.Equals(ImageFormat.Bmp)) {
                            imageFormat = ImageFormat.Bmp;
                        else if (bitmap.RawFormat.Equals(ImageFormat.Gif)) {
                            imageFormat = ImageFormat.Gif;
                        else if (bitmap.RawFormat.Equals(ImageFormat.Tiff)) {
                            imageFormat = ImageFormat.Tiff;

                        bitmap.Save(fileName, imageFormat);

Project available at: github

Structs data type in php?

You can use an array

$something = array(
   'key' => 'value',
   'key2' => 'value2'

or with standard object.

$something = new StdClass();

$something->key = 'value';
$something->key2 = 'value2';

Get contentEditable caret index position

$("#editable").on('keydown keyup mousedown mouseup',function(e){_x000D_
  border:1px solid #000;_x000D_
#editable p{_x000D_
<script src=""></script>_x000D_
<div contenteditable="true" id="editable">move the cursor to see position</div>_x000D_
position : <span id="position"></span>_x000D_

Core dumped, but core file is not in the current directory?

My efforts in WSL have been unsuccessful.

For those running on Windows Subsystem for Linux (WSL) there seems to be an open issue at this time for missing core dump files.

The comments indicate that

This is a known issue that we are aware of, it is something we are investigating.

Github issue

Windows Developer Feedback

Checkbox for nullable boolean

My model has a boolean that has to be nullable

Why? This doesn't make sense. A checkbox has two states: checked/unchecked, or True/False if you will. There is no third state.

Or wait you are using your domain models in your views instead of view models? That's your problem. So the solution for me is to use a view model in which you will define a simple boolean property:

public class MyViewModel
    public bool Foo { get; set; }

and now you will have your controller action pass this view model to the view and generate the proper checkbox.

Android: Creating a Circular TextView?

It's a rectangle that prevents oval shape background to get circular.
Making view a square will fix everything.

I found this solution to be clean and working for varying textsize and text length.

public class EqualWidthHeightTextView extends TextView {

    public EqualWidthHeightTextView(Context context) {

    public EqualWidthHeightTextView(Context context, AttributeSet attrs) {
        super(context, attrs);

    public EqualWidthHeightTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        int r = Math.max(getMeasuredWidth(),getMeasuredHeight());
        setMeasuredDimension(r, r);



    android:textColor="@color/white" />


<shape xmlns:android=""<br>
   <solid android:color="@color/light_blue"/>
   <stroke android:color="@color/white" android:width="1dp" />

iPhone App Icons - Exact Radius?

You can make four icons (as of today) for your app and they can all have a different look - not necessarily based on the 512x512 image.

  • corner radius for the 512x512 icon = 80 (iTunesArtwork)
  • corner radius for the 1024x1024 icon = 180 (iTunesArtwork Retina)
  • corner radius for the 57x57 icon = 9 (iPhone/iPod Touch)
  • corner radius for the 114x114 icon = 18 (iPhone/iPod Touch Retina)
  • corner radius for the 72x72 icon = 11 (iPad)
  • corner radius for the 144x144 icon = 23 (iPad Retina)

If you do create a set of custom icons, you can set the UIPrerenderedIcon option to true in your info.plist file and it will not add the gloss effect but it will place a black background under it and still round the image corners with these corner radii so if the corner radius on any of the icons is greater then it will show black around the edges/corners.

Edit: See comment from @devin-g-rhode and you can see that any future icon sizes should have a 1:6.4 ratio of corner radius to icon size. There is also a very good answer from which has the location of image mask files used in the SDK for rounding icon corners

To add a retina-compatible file, use the same file name and add '@2x'. So if I had a file for my 72x72 icon named icon.png, I would also add a 114x114 PNG file named [email protected] to the project/target and Xcode would automatically use that as the icon on a retina display. You can see this in action on the Summary page of the application target if you've done it right. The same works for your launch images. Use launch.png at 320x480 and [email protected] at 640x960.

Implementing autocomplete

I think you can use typeahead.js. There are typescript definitions for it. so it'll be easy to use it i guess if you are using typescript for development.

How to edit the legend entry of a chart in Excel?

Left Click on chart. «PivotTable Field List» will appear on right. On the right down quarter of PivotTable Field List (S Values), you see the names of the legends. Left Click on the legend name. Left Click on the «Value field settings». At the top there is «Source Name». You can’t change it. Below there is «Custom Name». Change the Custom Name as you wish. Now the legend name on the chart has the new name you gave.

Converting String Array to an Integer Array

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

class MultiArg {

    Scanner sc;
    int n;
    String as;
    List<Integer> numList = new ArrayList<Integer>();

    public void fun() {
        sc = new Scanner(;
        System.out.println("enter value");
        while (sc.hasNextInt())
            as = sc.nextLine();

    public void diplay() {
        Integer[] num = numList.toArray(new Integer[numList.size()]);
        System.out.println("show value " + as);
        for (Integer m : num) {
            System.out.println("\t" + m);

but to terminate the while loop you have to put any charecter at the end of input.

ex. input:

12 34 56 78 45 67 .


12 34 56 78 45 67

Read file content from S3 bucket with boto3

If you already know the filename, you can use the boto3 builtin download_fileobj

import boto3

from io import BytesIO

session = boto3.Session()
s3_client = session.client("s3")

f = BytesIO()
s3_client.download_fileobj(bucket_name, filename, f)