Programs & Examples On #Motion blur

Motion blur is the apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie or animation. It results when the image being recorded changes during the recording of a single frame, either due to rapid movement or long exposure. [http://en.wikipedia.org/wiki/Motion_blur]

Batch file to copy files from one folder to another folder

You may want to take a look at XCopy or RoboCopy which are pretty comprehensive solutions for nearly all file copy operations on Windows.

what innerHTML is doing in javascript?

The innerHTML property is part of the Document Object Model (DOM) that allows Javascript code to manipulate a website being displayed. Specifically, it allows reading and replacing everything within a given DOM element (HTML tag).

However, DOM manipulations using innerHTML are slower and more failure-prone than manipulations based on individual DOM objects.

How to return a custom object from a Spring Data JPA GROUP BY query

This SQL query return List< Object[] > would.

You can do it this way:

 @RestController
 @RequestMapping("/survey")
 public class SurveyController {

   @Autowired
   private SurveyRepository surveyRepository;

     @RequestMapping(value = "/find", method =  RequestMethod.GET)
     public Map<Long,String> findSurvey(){
       List<Object[]> result = surveyRepository.findSurveyCount();
       Map<Long,String> map = null;
       if(result != null && !result.isEmpty()){
          map = new HashMap<Long,String>();
          for (Object[] object : result) {
            map.put(((Long)object[0]),object[1]);
          }
       }
     return map;
     }
 }

How can I reverse the order of lines in a file?

at the end of your command put: | tac

tac does exactly what you're asking for, it "Write each FILE to standard output, last line first."

tac is the opposite of cat :-).

how to convert numeric to nvarchar in sql command

declare @MyNumber int
set @MyNumber = 123
select 'My number is ' + CAST(@MyNumber as nvarchar(20))

Make A List Item Clickable (HTML/CSS)

The li element supports an onclick event.

<ul>
<li onclick="location.href = 'http://stackoverflow.com/questions/3486110/make-a-list-item-clickable-html-css';">Make A List Item Clickable</li>
</ul>

Uninstalling Android ADT

I had the issue where after updating the SDK it would only update to version 20 and kept telling me that ANDROID 4.1 (API16) was available and only part of ANDROID 4.2 (API17) was available and there was no update to version 21.

After restarting several times and digging I found (was not obvious to me) going to the SDK Manager and going to FILE -> RELOAD solved the problem. Immediately the other uninstalled parts of API17 were there and I was able to update the SDK. Once updated to 4.2 then I could re-update to version 21 and voila.

Good luck! David

python: how to send mail with TO, CC and BCC?

You can try MIMEText

msg = MIMEText('text')
msg['to'] = 
msg['cc'] = 

then send msg.as_string()

https://docs.python.org/3.6/library/email.examples.html

How to send PUT, DELETE HTTP request in HttpURLConnection?

This is how it worked for me:

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("DELETE");
int responseCode = connection.getResponseCode();

Dump a mysql database to a plaintext (CSV) backup from the command line

Two line PowerShell answer:

# Store in variable
$Global:csv = (mysql -uroot -p -hlocalhost -Ddatabase_name -B -e "SELECT * FROM some_table") `
| ConvertFrom-Csv -Delimiter "`t"

# Out to csv
$Global:csv | Export-Csv "C:\temp\file.csv" -NoTypeInformation

Boom-bata-boom

-D = the name of your database

-e = query

-B = tab-delimited

Grep characters before and after match?

You can use regexp grep for finding + second grep for highlight

echo "some123_string_and_another" | grep -o -P '.{0,3}string.{0,4}' | grep string

23_string_and

enter image description here

Calculate business days

Here's a function from the user comments on the date() function page in the PHP manual. It's an improvement of an earlier function in the comments that adds support for leap years.

Enter the starting and ending dates, along with an array of any holidays that might be in between, and it returns the working days as an integer:

<?php
//The function returns the no. of business days between two dates and it skips the holidays
function getWorkingDays($startDate,$endDate,$holidays){
    // do strtotime calculations just once
    $endDate = strtotime($endDate);
    $startDate = strtotime($startDate);


    //The total number of days between the two dates. We compute the no. of seconds and divide it to 60*60*24
    //We add one to inlude both dates in the interval.
    $days = ($endDate - $startDate) / 86400 + 1;

    $no_full_weeks = floor($days / 7);
    $no_remaining_days = fmod($days, 7);

    //It will return 1 if it's Monday,.. ,7 for Sunday
    $the_first_day_of_week = date("N", $startDate);
    $the_last_day_of_week = date("N", $endDate);

    //---->The two can be equal in leap years when february has 29 days, the equal sign is added here
    //In the first case the whole interval is within a week, in the second case the interval falls in two weeks.
    if ($the_first_day_of_week <= $the_last_day_of_week) {
        if ($the_first_day_of_week <= 6 && 6 <= $the_last_day_of_week) $no_remaining_days--;
        if ($the_first_day_of_week <= 7 && 7 <= $the_last_day_of_week) $no_remaining_days--;
    }
    else {
        // (edit by Tokes to fix an edge case where the start day was a Sunday
        // and the end day was NOT a Saturday)

        // the day of the week for start is later than the day of the week for end
        if ($the_first_day_of_week == 7) {
            // if the start date is a Sunday, then we definitely subtract 1 day
            $no_remaining_days--;

            if ($the_last_day_of_week == 6) {
                // if the end date is a Saturday, then we subtract another day
                $no_remaining_days--;
            }
        }
        else {
            // the start date was a Saturday (or earlier), and the end date was (Mon..Fri)
            // so we skip an entire weekend and subtract 2 days
            $no_remaining_days -= 2;
        }
    }

    //The no. of business days is: (number of weeks between the two dates) * (5 working days) + the remainder
//---->february in none leap years gave a remainder of 0 but still calculated weekends between first and last day, this is one way to fix it
   $workingDays = $no_full_weeks * 5;
    if ($no_remaining_days > 0 )
    {
      $workingDays += $no_remaining_days;
    }

    //We subtract the holidays
    foreach($holidays as $holiday){
        $time_stamp=strtotime($holiday);
        //If the holiday doesn't fall in weekend
        if ($startDate <= $time_stamp && $time_stamp <= $endDate && date("N",$time_stamp) != 6 && date("N",$time_stamp) != 7)
            $workingDays--;
    }

    return $workingDays;
}

//Example:

$holidays=array("2008-12-25","2008-12-26","2009-01-01");

echo getWorkingDays("2008-12-22","2009-01-02",$holidays)
// => will return 7
?>

Purge or recreate a Ruby on Rails database

On Rails 4, all needed is

$ rake db:schema:load

That would delete the entire contents on your DB and recreate the schema from your schema.rb file, without having to apply all migrations one by one.

Visual studio equivalent of java System.out

Try: Console.WriteLine (type out for a Visual Studio snippet)

Console.WriteLine(stuff);

Another way is to use System.Diagnostics.Debug.WriteLine:

System.Diagnostics.Debug.WriteLine(stuff);

Debug.WriteLine may suit better for Output window in IDE because it will be rendered for both Console and Windows applications. Whereas Console.WriteLine won't be rendered in Output window but only in the Console itself in case of Console Application type.

Another difference is that Debug.WriteLine will not print anything in Release configuration.

jquery disable form submit on enter

I don't know if you already resolve this problem, or anyone trying to solve this right now but, here is my solution for this!

$j(':input:not(textarea)').keydown(function(event){
    var kc = event.witch || event.keyCode;
    if(kc == 13){
    event.preventDefault();
        $j(this).closest('form').attr('data-oldaction', function(){
            return $(this).attr('action');
        }).attr('action', 'javascript:;');

        alert('some_text_if_you_want');

        $j(this).closest('form').attr('action', function(){
            return $(this).attr('data-oldaction');
        });
        return false;
    }
});

How to listen for 'props' changes

You can use the watch mode to detect changes:

Do everything at atomic level. So first check if watch method itself is getting called or not by consoling something inside. Once it has been established that watch is getting called, smash it out with your business logic.

watch: { 
  myProp: function() {
   console.log('Prop changed')
  }
}

Go: panic: runtime error: invalid memory address or nil pointer dereference

The nil pointer dereference is in line 65 which is the defer in

res, err := client.Do(req)
defer res.Body.Close()

if err != nil {
    return nil, err
}

If err!= nil then res==nil and res.Body panics. Handle err before defering the res.Body.Close().

Jquery, checking if a value exists in array or not

Try jQuery.inArray()

Here is a jsfiddle link using the same code : http://jsfiddle.net/yrshaikh/SUKn2/

The $.inArray() method is similar to JavaScript's native .indexOf() method in that it returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0

Example Code :

<html>
   <head>
      <style>
         div { color:blue; }
         span { color:red; }
  </style>
      <script src="http://code.jquery.com/jquery-latest.js"></script>
   </head>
   <body>    
      <div>"John" found at <span></span></div>
      <div>4 found at <span></span></div>
      <div>"Karl" not found, so <span></span></div>
      <div>
         "Pete" is in the array, but not at or after index 2, so <span></span>
      </div>
      <script>
         var arr = [ 4, "Pete", 8, "John" ];
         var $spans = $("span");
         $spans.eq(0).text(jQuery.inArray("John", arr));
         $spans.eq(1).text(jQuery.inArray(4, arr));
         $spans.eq(2).text(jQuery.inArray("Karl", arr));
         $spans.eq(3).text(jQuery.inArray("Pete", arr, 2));
      </script>  
   </body>
</html>

Output:

"John" found at 3
4 found at 0
"Karl" not found, so -1
"Pete" is in the array, but not at or after index 2, so -1

jQuery Ajax Request inside Ajax Request

Call second ajax from 'complete'

Here is the example

   var dt='';
   $.ajax({
    type: "post",
    url: "ajax/example.php",
    data: 'page='+btn_page,
    success: function(data){
        dt=data;
        /*Do something*/
    },
    complete:function(){
        $.ajax({
           var a=dt; // This line shows error.
           type: "post",
           url: "example.php",
           data: 'page='+a,
           success: function(data){
              /*do some thing in second function*/
           },
       });
    }
});

How to place and center text in an SVG rectangle

Full Detail Blog :http://blog.techhysahil.com/svg/how-to-center-text-in-svg-shapes/

_x000D_
_x000D_
<svg width="600" height="600">_x000D_
  <!--   Circle -->_x000D_
  <g transform="translate(50,40)">_x000D_
    <circle cx="0" cy="0" r="35" stroke="#aaa" stroke-width="2" fill="#fff"></circle>_x000D_
    <text x="0" y="0" alignment-baseline="middle" font-size="12" stroke-width="0" stroke="#000" text-anchor="middle">HueLink</text>_x000D_
  </g>_x000D_
  _x000D_
  <!--   In Rectangle text position needs to be given half of width and height of rectangle respectively -->_x000D_
  <!--   Rectangle -->_x000D_
  <g transform="translate(150,20)">_x000D_
    <rect width="150" height="40" stroke="#aaa" stroke-width="2" fill="#fff"></rect>_x000D_
    <text x="75" y="20" alignment-baseline="middle" font-size="12" stroke-width="0" stroke="#000" text-anchor="middle">HueLink</text>_x000D_
  </g>_x000D_
  _x000D_
  <!--   Rectangle -->_x000D_
  <g transform="translate(120,140)">_x000D_
    <ellipse cx="0" cy="0" rx="100" ry="50" stroke="#aaa" stroke-width="2" fill="#fff"></ellipse>_x000D_
    <text x="0" y="0" alignment-baseline="middle" font-size="12" stroke-width="0" stroke="#000" text-anchor="middle">HueLink</text>_x000D_
  </g>_x000D_
  _x000D_
  _x000D_
</svg>
_x000D_
_x000D_
_x000D_

Convert a PHP script into a stand-alone windows executable

Peachpie

http://www.peachpie.io

https://github.com/iolevel/peachpie

Peachpie is PHP 7 compiler based on Roslyn by Microsoft and drawing from popular Phalanger. It allows PHP to be executed within the .NET/.NETCore by compiling the PHP code to pure MSIL.

Phalanger

http://v4.php-compiler.net/

http://wiki.php-compiler.net/Phalanger_Wiki

https://github.com/devsense/phalanger

Phalanger is a project which was started at Charles University in Prague and was supported by Microsoft. It compiles source code written in the PHP scripting language into CIL (Common Intermediate Language) byte-code. It handles the beginning of a compiling process which is completed by the JIT compiler component of the .NET Framework. It does not address native code generation nor optimization. Its purpose is to compile PHP scripts into .NET assemblies, logical units containing CIL code and meta-data.

Bambalam

https://github.com/xZero707/Bamcompile/

Bambalam PHP EXE Compiler/Embedder is a free command line tool to convert PHP applications to standalone Windows .exe applications. The exe files produced are totally standalone, no need for php dlls etc. The php code is encoded using the Turck MMCache Encode library so it's a perfect solution if you want to distribute your application while protecting your source code. The converter is also suitable for producing .exe files for windowed PHP applications (created using for example the WinBinder library). It's also good for making stand-alone PHP Socket servers/clients (using the php_sockets.dll extension). It's NOT really a compiler in the sense that it doesn't produce native machine code from PHP sources, but it works!

ZZEE PHPExe

http://www.zzee.com/phpexe/

ZZEE PHPExe compiles PHP, HTML, Javascript, Flash and other web files into Windows GUI exes. You can rapidly develop Windows GUI applications by employing the familiar PHP web paradigm. You can use the same code for online and Windows applications with little or no modification. It is a Commercial product.

phc-win

http://wiki.swiftlytilting.com/Phc-win

The PHP extension bcompiler is used to compile PHP script code into PHP bytecode. This bytecode can be included just like any php file as long as the bcompiler extension is loaded. Once all the bytecode files have been created, a modified Embeder is used to pack all of the project files into the program exe.

Requires

  • php5ts.dll
  • php_win32std.dll
  • php_bcompiler.dll
  • php-embed.ini

ExeOutput

http://www.exeoutput.com/

Commercial

WinBinder

http://winbinder.org/

WinBinder is an open source extension to PHP, the script programming language. It allows PHP programmers to easily build native Windows applications, producing quick and rewarding results with minimum effort. Even short scripts with a few dozen lines can generate a useful program, thanks to the power and flexibility of PHP.

PHPDesktop

https://github.com/cztomczak/phpdesktop

PHP Desktop is an open source project founded by Czarek Tomczak in 2012 to provide a way for developing native desktop applications using web technologies such as PHP, HTML5, JavaScript & SQLite. This project is more than just a PHP to EXE compiler, it embeds a web-browser (Internet Explorer or Chrome embedded), a Mongoose web-server and a PHP interpreter. The development workflow you are used to remains the same, the step of turning an existing website into a desktop application is basically a matter of copying it to "www/" directory. Using SQLite database is optional, you could embed mysql/postgresql database in application's installer.

PHP Nightrain

https://github.com/kjellberg/nightrain

Using PHP Nightrain you will be able to deploy and run HTML, CSS, JavaScript and PHP web applications as a native desktop application on Windows, Mac and the Linux operating systems. Popular PHP Frameworks (e.g. CakePHP, Laravel, Drupal, etc…) are well supported!

phc-win "fork"

https://github.com/RDashINC/phc-win

A more-or-less forked version of phc-win, it uses the same techniques as phc-win but supports almost all modern PHP versions. (5.3, 5.4, 5.5, 5.6, etc) It also can use Enigma VB to combine the php5ts.dll with your exe, aswell as UPX compress it. Lastly, it has win32std and winbinder compilied statically into PHP.

EDIT

Another option is to use

http://www.appcelerator.com/products/titanium-cross-platform-application-development/

an online compiler that can build executables for a number of different platforms, from a number of different languages including PHP

TideSDK

http://www.tidesdk.org/

TideSDK is actually the renamed Titanium Desktop project. Titanium remained focused on mobile, and abandoned the desktop version, which was taken over by some people who have open sourced it and dubbed it TideSDK.

Generally, TideSDK uses HTML, CSS and JS to render applications, but it supports scripted languages like PHP, as a plug-in module, as well as other scripting languages like Python and Ruby.

Make the image go behind the text and keep it in center using CSS

Try this code:

body {z-index:0}
img.center {z-index:-1; margin-left:auto; margin-right:auto}

Setting the left & right margins to auto should center your image.

Xcode variables

Here's a list of the environment variables. I think you might want CURRENT_VARIANT. See also BUILD_VARIANTS.

Java enum with multiple value types

First, the enum methods shouldn't be in all caps. They are methods just like other methods, with the same naming convention.

Second, what you are doing is not the best possible way to set up your enum. Instead of using an array of values for the values, you should use separate variables for each value. You can then implement the constructor like you would any other class.

Here's how you should do it with all the suggestions above:

public enum States {
    ...
    MASSACHUSETTS("Massachusetts",  "MA",   true),
    MICHIGAN     ("Michigan",       "MI",   false),
    ...; // all 50 of those

    private final String full;
    private final String abbr;
    private final boolean originalColony;

    private States(String full, String abbr, boolean originalColony) {
        this.full = full;
        this.abbr = abbr;
        this.originalColony = originalColony;
    }

    public String getFullName() {
        return full;
    }

    public String getAbbreviatedName() {
        return abbr;
    }

    public boolean isOriginalColony(){
        return originalColony;
    }
}

What is the Eclipse shortcut for "public static void main(String args[])"?

As bmargulies mentioned:

Preferences>Java>Editor>Templates>New...

enter image description here

enter image description here

Now, type psvm then Ctrl + Space on Mac or Windows.

Unicode character in PHP string

PHP does not know these Unicode escape sequences. But as unknown escape sequences remain unaffected, you can write your own function that converts such Unicode escape sequences:

function unicodeString($str, $encoding=null) {
    if (is_null($encoding)) $encoding = ini_get('mbstring.internal_encoding');
    return preg_replace_callback('/\\\\u([0-9a-fA-F]{4})/u', create_function('$match', 'return mb_convert_encoding(pack("H*", $match[1]), '.var_export($encoding, true).', "UTF-16BE");'), $str);
}

Or with an anonymous function expression instead of create_function:

function unicodeString($str, $encoding=null) {
    if (is_null($encoding)) $encoding = ini_get('mbstring.internal_encoding');
    return preg_replace_callback('/\\\\u([0-9a-fA-F]{4})/u', function($match) use ($encoding) {
        return mb_convert_encoding(pack('H*', $match[1]), $encoding, 'UTF-16BE');
    }, $str);
}

Its usage:

$str = unicodeString("\u1000");

IsNumeric function in c#

public bool IsNumeric(string value)
{
    return value.All(char.IsNumber);
}

Check difference in seconds between two times

DateTime has a Subtract method and an overloaded - operator for just such an occasion:

DateTime now = DateTime.UtcNow;
TimeSpan difference = now.Subtract(otherTime); // could also write `now - otherTime`
if (difference.TotalSeconds > 5) { ... }

Python Matplotlib Y-Axis ticks on Right Side of Plot

Just is case somebody asks (like I did), this is also possible when one uses subplot2grid. For example:

import matplotlib.pyplot as plt
plt.subplot2grid((3,2), (0,1), rowspan=3)
plt.plot([2,3,4,5])
plt.tick_params(axis='y', which='both', labelleft='off', labelright='on')
plt.show()

It will show this:

enter image description here

C++ floating point to integer type conversions

Size of some float types may exceed the size of int. This example shows a safe conversion of any float type to int using the int safeFloatToInt(const FloatType &num); function:

#include <iostream>
#include <limits>
using namespace std;

template <class FloatType>
int safeFloatToInt(const FloatType &num) {
   //check if float fits into integer
   if ( numeric_limits<int>::digits < numeric_limits<FloatType>::digits) {
      // check if float is smaller than max int
      if( (num < static_cast<FloatType>( numeric_limits<int>::max())) &&
          (num > static_cast<FloatType>( numeric_limits<int>::min())) ) {
         return static_cast<int>(num); //safe to cast
      } else {
        cerr << "Unsafe conversion of value:" << num << endl;
        //NaN is not defined for int return the largest int value
        return numeric_limits<int>::max();
      }
   } else {
      //It is safe to cast
      return static_cast<int>(num);
   }
}
int main(){
   double a=2251799813685240.0;
   float b=43.0;
   double c=23333.0;
   //unsafe cast
   cout << safeFloatToInt(a) << endl;
   cout << safeFloatToInt(b) << endl;
   cout << safeFloatToInt(c) << endl;
   return 0;
}

Result:

Unsafe conversion of value:2.2518e+15
2147483647
43
23333

How to Multi-thread an Operation Within a Loop in Python

First, in Python, if your code is CPU-bound, multithreading won't help, because only one thread can hold the Global Interpreter Lock, and therefore run Python code, at a time. So, you need to use processes, not threads.

This is not true if your operation "takes forever to return" because it's IO-bound—that is, waiting on the network or disk copies or the like. I'll come back to that later.


Next, the way to process 5 or 10 or 100 items at once is to create a pool of 5 or 10 or 100 workers, and put the items into a queue that the workers service. Fortunately, the stdlib multiprocessing and concurrent.futures libraries both wraps up most of the details for you.

The former is more powerful and flexible for traditional programming; the latter is simpler if you need to compose future-waiting; for trivial cases, it really doesn't matter which you choose. (In this case, the most obvious implementation with each takes 3 lines with futures, 4 lines with multiprocessing.)

If you're using 2.6-2.7 or 3.0-3.1, futures isn't built in, but you can install it from PyPI (pip install futures).


Finally, it's usually a lot simpler to parallelize things if you can turn the entire loop iteration into a function call (something you could, e.g., pass to map), so let's do that first:

def try_my_operation(item):
    try:
        api.my_operation(item)
    except:
        print('error with item')

Putting it all together:

executor = concurrent.futures.ProcessPoolExecutor(10)
futures = [executor.submit(try_my_operation, item) for item in items]
concurrent.futures.wait(futures)

If you have lots of relatively small jobs, the overhead of multiprocessing might swamp the gains. The way to solve that is to batch up the work into larger jobs. For example (using grouper from the itertools recipes, which you can copy and paste into your code, or get from the more-itertools project on PyPI):

def try_multiple_operations(items):
    for item in items:
        try:
            api.my_operation(item)
        except:
            print('error with item')

executor = concurrent.futures.ProcessPoolExecutor(10)
futures = [executor.submit(try_multiple_operations, group) 
           for group in grouper(5, items)]
concurrent.futures.wait(futures)

Finally, what if your code is IO bound? Then threads are just as good as processes, and with less overhead (and fewer limitations, but those limitations usually won't affect you in cases like this). Sometimes that "less overhead" is enough to mean you don't need batching with threads, but you do with processes, which is a nice win.

So, how do you use threads instead of processes? Just change ProcessPoolExecutor to ThreadPoolExecutor.

If you're not sure whether your code is CPU-bound or IO-bound, just try it both ways.


Can I do this for multiple functions in my python script? For example, if I had another for loop elsewhere in the code that I wanted to parallelize. Is it possible to do two multi threaded functions in the same script?

Yes. In fact, there are two different ways to do it.

First, you can share the same (thread or process) executor and use it from multiple places with no problem. The whole point of tasks and futures is that they're self-contained; you don't care where they run, just that you queue them up and eventually get the answer back.

Alternatively, you can have two executors in the same program with no problem. This has a performance cost—if you're using both executors at the same time, you'll end up trying to run (for example) 16 busy threads on 8 cores, which means there's going to be some context switching. But sometimes it's worth doing because, say, the two executors are rarely busy at the same time, and it makes your code a lot simpler. Or maybe one executor is running very large tasks that can take a while to complete, and the other is running very small tasks that need to complete as quickly as possible, because responsiveness is more important than throughput for part of your program.

If you don't know which is appropriate for your program, usually it's the first.

How to align an image dead center with bootstrap

I am using justify-content-center class to a row within a container. Works well with Bootstrap 4.

<div class="container-fluid">
  <div class="row justify-content-center">
   <img src="logo.png" />
  </div>
</div>

Alternative to mysql_real_escape_string without connecting to DB

It is impossible to safely escape a string without a DB connection. mysql_real_escape_string() and prepared statements need a connection to the database so that they can escape the string using the appropriate character set - otherwise SQL injection attacks are still possible using multi-byte characters.

If you are only testing, then you may as well use mysql_escape_string(), it's not 100% guaranteed against SQL injection attacks, but it's impossible to build anything safer without a DB connection.

How to display an IFRAME inside a jQuery UI dialog

There are multiple ways you can do this but I am not sure which one is the best practice. The first approach is you can append an iFrame in the dialog container on the fly with your given link:

$("#dialog").append($("<iframe />").attr("src", "your link")).dialog({dialogoptions});

Another would be to load the content of your external link into the dialog container using ajax.

$("#dialog").load("yourajaxhandleraddress.htm").dialog({dialogoptions});

Both works fine but depends on the external content.

Best way to store a key=>value array in JavaScript?

If I understood you correctly:

var hash = {};
hash['bob'] = 123;
hash['joe'] = 456;

var sum = 0;
for (var name in hash) {
    sum += hash[name];
}
alert(sum); // 579

What's the difference between lists and tuples?

Difference between list and tuple

  1. Literal

    someTuple = (1,2)
    someList  = [1,2] 
    
  2. Size

    a = tuple(range(1000))
    b = list(range(1000))
    
    a.__sizeof__() # 8024
    b.__sizeof__() # 9088
    

    Due to the smaller size of a tuple operation, it becomes a bit faster, but not that much to mention about until you have a huge number of elements.

  3. Permitted operations

    b    = [1,2]   
    b[0] = 3       # [3, 2]
    
    a    = (1,2)
    a[0] = 3       # Error
    

    That also means that you can't delete an element or sort a tuple. However, you could add a new element to both list and tuple with the only difference that since the tuple is immutable, you are not really adding an element but you are creating a new tuple, so the id of will change

    a     = (1,2)
    b     = [1,2]  
    
    id(a)          # 140230916716520
    id(b)          # 748527696
    
    a   += (3,)    # (1, 2, 3)
    b   += [3]     # [1, 2, 3]
    
    id(a)          # 140230916878160
    id(b)          # 748527696
    
  4. Usage

    As a list is mutable, it can't be used as a key in a dictionary, whereas a tuple can be used.

    a    = (1,2)
    b    = [1,2] 
    
    c = {a: 1}     # OK
    c = {b: 1}     # Error
    

Exporting the values in List to excel

The simplest way using ClosedXml.

Imports ClosedXML.Excel

var dataList = new List<string>() { "a", "b", "c" };
var workbook = new XLWorkbook();     //creates the workbook
var wsDetailedData = workbook.AddWorksheet("data"); //creates the worksheet with sheetname 'data'
wsDetailedData.Cell(1, 1).InsertTable(dataList); //inserts the data to cell A1 including default column name
workbook.SaveAs(@"C:\data.xlsx"); //saves the workbook

For more info, you can also check wiki of ClosedXml. https://github.com/closedxml/closedxml/wiki

Can't access 127.0.0.1

In windows first check under services if world wide web publishing services is running. If not start it.

If you cannot find it switch on IIS features of windows: In 7,8,10 it is under control panel , "turn windows features on or off". Internet Information Services World Wide web services and Internet information Services Hostable Core are required. Not sure if there is another way to get it going on windows, but this worked for me for all browsers. You might need to add localhost or http:/127.0.0.1 to the trusted websites also under IE settings.

How do I capitalize first letter of first name and last name in C#?

If your using vS2k8, you can use an extension method to add it to the String class:

public static string FirstLetterToUpper(this String input)
{
    return input = input.Substring(0, 1).ToUpper() + 
       input.Substring(1, input.Length - 1);
}

Getting command-line password input in Python

15.7. getpass — Portable password input

#!/usr/bin/python3
from getpass import getpass
passwd = getpass("password: ")
print(passwd)

You can read more here

Duplicate line in Visual Studio Code

Mac:

Duplicate Line Down :shift + option + ?

Duplicate Line Up:shift + option + ?

Split a string into an array of strings based on a delimiter

I always use something similar to this:

Uses
   StrUtils, Classes;

Var
  Str, Delimiter : String;
begin
  // Str is the input string, Delimiter is the delimiter
  With TStringList.Create Do
  try
    Text := ReplaceText(S,Delim,#13#10);

    // From here on and until "finally", your desired result strings are
    // in strings[0].. strings[Count-1)

  finally
    Free; //Clean everything up, and liberate your memory ;-)
  end;

end;

How to get a Fragment to remove itself, i.e. its equivalent of finish()?

While it might not be the best approach the closest equivalent I can think of that works is this with the support/compatibility library

getActivity().getSupportFragmentManager().beginTransaction().remove(this).commit();

or

getActivity().getFragmentManager().beginTransaction().remove(this).commit();

otherwise.

In addition you can use the backstack and pop it. However keep in mind that the fragment might not be on the backstack (depending on the fragmenttransaction that got it there..) or it might not be the last one that got onto the stack so popping the stack could remove the wrong one...

Getting scroll bar width using JavaScript

Here's an easy way using jQuery.

var scrollbarWidth = jQuery('div.withScrollBar').get(0).scrollWidth - jQuery('div.withScrollBar').width();

Basically we subtract the scrollable width from the overall width and that should provide the scrollbar's width. Of course, you'd want to cache the jQuery('div.withScrollBar') selection so you're not doing that part twice.

ASP.NET 4.5 has not been registered on the Web server

I had the same problem. After a long search , I change the application pool to ASP.NET v4.x in the IIS manager.

Angular get object from array by Id

CASE - 1

Using array.filter() We can get an array of objects which will match with our condition.
see the working example.

_x000D_
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var questions = [
      {id: 1, question: "Do you feel a connection to a higher source and have a sense of comfort knowing that you are part of something greater than yourself?", category: "Spiritual", subs: []},
      {id: 2, question: "Do you feel you are free of unhealthy behavior that impacts your overall well-being?", category: "Habits", subs: []},
      {id: 3, question: "1 Do you feel you have healthy and fulfilling relationships?", category: "Relationships", subs: []},
      {id: 3, question: "2 Do you feel you have healthy and fulfilling relationships?", category: "Relationships", subs: []},
      {id: 3, question: "3 Do you feel you have healthy and fulfilling relationships?", category: "Relationships", subs: []},
      {id: 4, question: "Do you feel you have a sense of purpose and that you have a positive outlook about yourself and life?", category: "Emotional Well-being", subs: []},
      {id: 5, question: "Do you feel you have a healthy diet and that you are fueling your body for optimal health? ", category: "Eating Habits ", subs: []},
      {id: 6, question: "Do you feel that you get enough rest and that your stress level is healthy?", category: "Relaxation ", subs: []},
      {id: 7, question: "Do you feel you get enough physical activity for optimal health?", category: "Exercise ", subs: []},
      {id: 8, question: "Do you feel you practice self-care and go to the doctor regularly?", category: "Medical Maintenance", subs: []},
      {id: 9, question: "Do you feel satisfied with your income and economic stability?", category: "Financial", subs: []},
      {id: 10, question: "1 Do you feel you do fun things and laugh enough in your life?", category: "Play", subs: []},
      {id: 10, question: "2 Do you feel you do fun things and laugh enough in your life?", category: "Play", subs: []},
      {id: 11, question: "Do you feel you have a healthy sense of balance in this area of your life?", category: "Work-life Balance", subs: []},
      {id: 12, question: "Do you feel a sense of peace and contentment  in your home? ", category: "Home Environment", subs: []},
      {id: 13, question: "Do you feel that you are challenged and growing as a person?", category: "Intellectual Wellbeing", subs: []},
      {id: 14, question: "Do you feel content with what you see when you look in the mirror?", category: "Self-image", subs: []},
      {id: 15, question: "Do you feel engaged at work and a sense of fulfillment with your job?", category: "Work Satisfaction", subs: []}
];

function filter(){
  console.clear();
  var filter_id = document.getElementById("filter").value;
  var filter_array = questions.filter(x => x.id == filter_id);
  console.log(filter_array);
}
_x000D_
button {
  background: #0095ff;
  color: white;
  border: none;
  border-radius: 3px;
  padding: 8px;
  cursor: pointer;
}

input {
  padding: 8px;
}
_x000D_
<div>
  <label for="filter"></label>
  <input id="filter" type="number" name="filter" placeholder="Enter id which you want to filter">
  <button onclick="filter()">Filter</button>
</div>
_x000D_
_x000D_
_x000D_

CASE - 2

Using array.find() we can get first matched item and break the iteration.

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_x000D_
var questions = [
      {id: 1, question: "Do you feel a connection to a higher source and have a sense of comfort knowing that you are part of something greater than yourself?", category: "Spiritual", subs: []},
      {id: 2, question: "Do you feel you are free of unhealthy behavior that impacts your overall well-being?", category: "Habits", subs: []},
      {id: 3, question: "1 Do you feel you have healthy and fulfilling relationships?", category: "Relationships", subs: []},
      {id: 3, question: "2 Do you feel you have healthy and fulfilling relationships?", category: "Relationships", subs: []},
      {id: 3, question: "3 Do you feel you have healthy and fulfilling relationships?", category: "Relationships", subs: []},
      {id: 4, question: "Do you feel you have a sense of purpose and that you have a positive outlook about yourself and life?", category: "Emotional Well-being", subs: []},
      {id: 5, question: "Do you feel you have a healthy diet and that you are fueling your body for optimal health? ", category: "Eating Habits ", subs: []},
      {id: 6, question: "Do you feel that you get enough rest and that your stress level is healthy?", category: "Relaxation ", subs: []},
      {id: 7, question: "Do you feel you get enough physical activity for optimal health?", category: "Exercise ", subs: []},
      {id: 8, question: "Do you feel you practice self-care and go to the doctor regularly?", category: "Medical Maintenance", subs: []},
      {id: 9, question: "Do you feel satisfied with your income and economic stability?", category: "Financial", subs: []},
      {id: 10, question: "1 Do you feel you do fun things and laugh enough in your life?", category: "Play", subs: []},
      {id: 10, question: "2 Do you feel you do fun things and laugh enough in your life?", category: "Play", subs: []},
      {id: 11, question: "Do you feel you have a healthy sense of balance in this area of your life?", category: "Work-life Balance", subs: []},
      {id: 12, question: "Do you feel a sense of peace and contentment  in your home? ", category: "Home Environment", subs: []},
      {id: 13, question: "Do you feel that you are challenged and growing as a person?", category: "Intellectual Wellbeing", subs: []},
      {id: 14, question: "Do you feel content with what you see when you look in the mirror?", category: "Self-image", subs: []},
      {id: 15, question: "Do you feel engaged at work and a sense of fulfillment with your job?", category: "Work Satisfaction", subs: []}
];

function find(){
  console.clear();
  var find_id = document.getElementById("find").value;
  var find_object = questions.find(x => x.id == find_id);
  console.log(find_object);
}
_x000D_
button {
  background: #0095ff;
  color: white;
  border: none;
  border-radius: 3px;
  padding: 8px;
  cursor: pointer;
}

input {
  padding: 8px;
  width: 200px;
}
_x000D_
<div>
  <label for="find"></label>
  <input id="find" type="number" name="find" placeholder="Enter id which you want to find">
  <button onclick="find()">Find</button>
</div>
_x000D_
_x000D_
_x000D_

"message failed to fetch from registry" while trying to install any module

You also need to install software-properties-common for add-apt-repository to work. so it will be

sudo apt-get purge nodejs npm
sudo apt-get install -y python-software-properties python g++ make software-properties-common
sudo add-apt-repository ppa:chris-lea/node.js
sudo apt-get update
sudo apt-get install nodejs

What is PostgreSQL equivalent of SYSDATE from Oracle?

The following functions are available to obtain the current date and/or time in PostgreSQL:

CURRENT_TIME

CURRENT_DATE

CURRENT_TIMESTAMP

Example

SELECT CURRENT_TIME;
08:05:18.864750+05:30

SELECT CURRENT_DATE;
2020-05-14

SELECT CURRENT_TIMESTAMP;
2020-05-14 08:04:51.290498+05:30

postgresql docs

What is a good way to handle exceptions when trying to read a file in python?

Adding to @Josh's example;

fName = [FILE TO OPEN]
if os.path.exists(fName):
    with open(fName, 'rb') as f:
        #add you code to handle the file contents here.
elif IOError:
    print "Unable to open file: "+str(fName)

This way you can attempt to open the file, but if it doesn't exist (if it raises an IOError), alert the user!

How to get a right click mouse event? Changing EventArgs to MouseEventArgs causes an error in Form1Designer?

This would definitely help Many!

private void axWindowsMediaPlayer1_ClickEvent(object sender, AxWMPLib._WMPOCXEvents_ClickEvent e)
    {
        if(e.nButton==2)
        {
            contextMenuStrip1.Show(MousePosition);
        }
    }

[ e.nbutton==2 ] is like [ e.button==MouseButtons.Right ]

Expand a random range from 1–5 to 1–7

First thing came on my mind is this. But i have no idea whether its uniformly distributed. Implemented in python

import random

def rand5():

return random.randint(1,5)

def rand7():

return ( ( (rand5() -1) * rand5() ) %7 )+1

Remove and Replace Printed items

import sys
import time

a = 0  
for x in range (0,3):  
    a = a + 1  
    b = ("Loading" + "." * a)
    # \r prints a carriage return first, so `b` is printed on top of the previous line.
    sys.stdout.write('\r'+b)
    time.sleep(0.5)
print (a)

Note that you might have to run sys.stdout.flush() right after sys.stdout.write('\r'+b) depending on which console you are doing the printing to have the results printed when requested without any buffering.

How to convert number to words in java

You can use RuleBasedNumberFormat. for example result will give you Ninety

ULocale locale = new ULocale(Locale.US);  //us english
Double d = Double.parseDouble(90);
NumberFormat formatter = new RuleBasedNumberFormat(locale, RuleBasedNumberFormat.SPELLOUT);
String result = formatter.format(d);

It supports a wide range of languages.

Omitting one Setter/Getter in Lombok

If you have setter and getter as private it will come up in PMD checks.

Smooth scroll to specific div on click

do:

$("button").click(function() {
    $('html,body').animate({
        scrollTop: $(".second").offset().top},
        'slow');
});

Updated Jsfiddle

django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: No module named MySQLdb

Seems like you don't have permission to the Python folder. Try sudo chown -R $USER /Library/Python/2.7

Xcode 9 Swift Language Version (SWIFT_VERSION)

This Solution works when nothing else works:

I spent more than a week to convert the whole project and came to a solution below:

First, de-integrate the cocopods dependency from the project and then start converting the project to the latest swift version.

Go to Project Directory in the Terminal and Type:

pod deintegrate

This will de-integrate cocopods from the project and No traces of CocoaPods will be left in the project. But at the same time, it won't delete the xcworkspace and podfiles. It's ok if they are present.

Now you have to open xcodeproj(not xcworkspace) and you will get lots of errors because you have called cocoapods dependency methods in your main projects.

So to remove those errors you have two options:

  1. Comment down all the code you have used from cocoapods library.
  2. Create a wrapper class which has dummy methods similar to cocopods library, and then call it.

Once all the errors get removed you can convert the code to the latest swift version.

Sometimes if you are getting weird errors then try cleaning derived data and try again.

How to use executables from a package installed locally in node_modules?

update: If you're on the recent npm (version >5.2)

You can use:

npx <command>

npx looks for command in .bin directory of your node_modules

old answer:

For Windows

Store the following in a file called npm-exec.bat and add it to your %PATH%

@echo off
set cmd="npm bin"
FOR /F "tokens=*" %%i IN (' %cmd% ') DO SET modules=%%i
"%modules%"\%*

Usage

Then you can use it like npm-exec <command> <arg0> <arg1> ...

For example

To execute wdio installed in local node_modules directory, do:

npm-exec wdio wdio.conf.js

i.e. it will run .\node_modules\.bin\wdio wdio.conf.js

how to check for null with a ng-if values in a view with angularjs?

You can also use ng-template, I think that would be more efficient while run time :)

<div ng-if="!test.view; else somethingElse">1</div>
<ng-template #somethingElse>
    <div>2</div>
</ng-template>

Cheers

How to find list intersection?

A functional way can be achieved using filter and lambda operator.

list1 = [1,2,3,4,5,6]

list2 = [2,4,6,9,10]

>>> list(filter(lambda x:x in list1, list2))

[2, 4, 6]

Edit: It filters out x that exists in both list1 and list, set difference can also be achieved using:

>>> list(filter(lambda x:x not in list1, list2))
[9,10]

Edit2: python3 filter returns a filter object, encapsulating it with list returns the output list.

Getting data-* attribute for onclick event for an html element

You can achieve this $(identifier).data('id') using jquery,

    <script type="text/javascript">

        function goDoSomething(identifier){     
            alert("data-id:"+$(identifier).data('id')+", data-option:"+$(identifier).data('option'));               
        }

    </script>

    <a id="option1" 
       data-id="10" 
       data-option="21" 
       href="#" 
       onclick="goDoSomething(this);">
           Click to do something
    </a>

javascript : You can use getAttribute("attributename") if want to use javascript tag,

    <script type="text/javascript">

        function goDoSomething(d){
            alert(d.getAttribute("data-id"));
        }

    </script>

    <a id="option1" 
       data-id="10" 
       data-option="21" 
       href="#" 
       onclick="goDoSomething(this);">
           Click to do something
    </a>

Or:

    <script type="text/javascript">

        function goDoSomething(data_id, data_option){       

            alert("data-id:"+data_id+", data-option:"+data_option);
        }

    </script>

    <a id="option1" 
       data-id="10" 
       data-option="21" 
       href="#" 
       onclick="goDoSomething(this.getAttribute('data-id'), this.getAttribute('data-option'));">
           Click to do something
    </a>

"git rebase origin" vs."git rebase origin/master"

git rebase origin means "rebase from the tracking branch of origin", while git rebase origin/master means "rebase from the branch master of origin"

You must have a tracking branch in ~/Desktop/test, which means that git rebase origin knows which branch of origin to rebase with. If no tracking branch exists (in the case of ~/Desktop/fallstudie), git doesn't know which branch of origin it must take, and fails.

To fix this, you can make the branch track origin/master with:

git branch --set-upstream-to=origin/master 

Or, if master isn't the currently checked-out branch:

git branch --set-upstream-to=origin/master master

Display tooltip on Label's hover?

Are you find with using standard tooltip? You could use title attribute like

<label for="male" title="Hello This Will Have Some Value">Hello...</label>

You could add the title attribute of same value to the element that label is for as well.

How to Exit a Method without Exiting the Program?

In addition to Mark's answer, you also need to be aware of scope, which (as in C/C++) is specified using braces. So:

if (textBox1.Text == "" || textBox1.Text == String.Empty || textBox1.TextLength == 0)
    textBox3.Text += "[-] Listbox is Empty!!!!\r\n";
return;

will always return at that point. However:

if (textBox1.Text == "" || textBox1.Text == String.Empty || textBox1.TextLength == 0)
{
    textBox3.Text += "[-] Listbox is Empty!!!!\r\n";
    return;
}

will only return if it goes into that if statement.

How can I align two divs horizontally?

<html>
<head>
<style type="text/css">
#floatingDivs{float:left;}
</style>
</head>

<body>
<div id="floatingDivs">
    <span>source list</span>
    <select size="10">
        <option />
        <option />
        <option />
    </select>
</div>

<div id="floatingDivs">
    <span>destination list</span>
    <select size="10">
        <option />
        <option />
        <option />
    </select>
</div>

</body>
</html>

What does it mean to inflate a view from an xml file?

I think here "inflating a view" means fetching the layout.xml file drawing a view specified in that xml file and POPULATING ( = inflating ) the parent viewGroup with the created View.

How to hide a <option> in a <select> menu with CSS?

Since you're already using JS, you could create a hidden SELECT element on the page, and for each item you are trying to hide in that list, move it to the hidden list. This way, they can be easily restored.

I don't know a way offhand of doing it in pure CSS... I would have thought that the display:none trick would have worked.

How do I pretty-print existing JSON data with Java?

Use gson. https://www.mkyong.com/java/how-to-enable-pretty-print-json-output-gson/

Gson gson = new GsonBuilder().setPrettyPrinting().create();
String json = gson.toJson(my_bean);

output

{
  "name": "mkyong",
  "age": 35,
  "position": "Founder",
  "salary": 10000,
  "skills": [
    "java",
    "python",
    "shell"
  ]
}

How can I get the last day of the month in C#?

Something like:

DateTime today = DateTime.Today;
DateTime endOfMonth = new DateTime(today.Year, today.Month, 1).AddMonths(1).AddDays(-1);

Which is to say that you get the first day of next month, then subtract a day. The framework code will handle month length, leap years and such things.

Load HTML page dynamically into div with jQuery

I think this would do it:

<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
<script type="text/javascript">
    $(document).ready(function(){

         $(".divlink").click(function(){
         $("#content").attr("src" , $(this).attr("ref"));

});

});
</script>
</head>
<body>
<iframe id="content"></iframe>

<a href="#" ref="page1.html" class="divlink" >Page 1</a><br />
<a href="#" ref="page2.html" class="divlink" >Page 2</a><br />
<a href="#" ref="page3.html" class="divlink" >Page 3</a><br />
<a href="#" ref="page4.html" class="divlink" >Page 4</a><br />
<a href="#" ref="page5.html" class="divlink" >Page 5</a><br />
<a href="#" ref="page6.html" class="divlink" >Page 6</a><br />
</body>
</html>

By the way if you can avoid Jquery, you can just use the target attribute of <a> element:

<html>
<body>
<iframe id="content" name="content"></iframe>

<a href="page1.html" target="content" >Page 1</a><br />
<a href="page2.html" target="content" >Page 2</a><br />
<a href="page3.html" target="content" >Page 3</a><br />
<a href="page4.html" target="content" >Page 4</a><br />
<a href="page5.html" target="content" >Page 5</a><br />
<a href="page6.html" target="content" >Page 6</a><br />
</body>
</html> 

PostgreSQL: FOREIGN KEY/ON DELETE CASCADE

Excerpt from PostgreSQL documentation:

Restricting and cascading deletes are the two most common options. [...] CASCADE specifies that when a referenced row is deleted, row(s) referencing it should be automatically deleted as well.

This means that if you delete a category – referenced by books – the referencing book will also be deleted by ON DELETE CASCADE.

Example:

CREATE SCHEMA shire;

CREATE TABLE shire.clans (
    id serial PRIMARY KEY,
    clan varchar
);

CREATE TABLE shire.hobbits (
    id serial PRIMARY KEY,
    hobbit varchar,
    clan_id integer REFERENCES shire.clans (id) ON DELETE CASCADE
);

DELETE FROM clans will CASCADE to hobbits by REFERENCES.

sauron@mordor> psql
sauron=# SELECT * FROM shire.clans;
 id |    clan    
----+------------
  1 | Baggins
  2 | Gamgi
(2 rows)

sauron=# SELECT * FROM shire.hobbits;
 id |  hobbit  | clan_id 
----+----------+---------
  1 | Bilbo    |       1
  2 | Frodo    |       1
  3 | Samwise  |       2
(3 rows)

sauron=# DELETE FROM shire.clans WHERE id = 1 RETURNING *;
 id |  clan   
----+---------
  1 | Baggins
(1 row)

DELETE 1
sauron=# SELECT * FROM shire.hobbits;
 id |  hobbit  | clan_id 
----+----------+---------
  3 | Samwise  |       2
(1 row)

If you really need the opposite (checked by the database), you will have to write a trigger!

Java Compare Two List's object values?

I got this solution for above problem

public boolean compareLists(List<MyData> prevList, List<MyData> modelList) {
        if (prevList.size() == modelList.size()) {
            for (MyData modelListdata : modelList) {
                for (MyData prevListdata : prevList) {
                    if (prevListdata.getName().equals(modelListdata.getName())
                            && prevListdata.isCheck() != modelListdata.isCheck()) {
                        return  true;

                    }
                }

            }
        }
        else{
            return true;
        }
        return false; 

    }

EDITED:-
How can we cover this... Imagine if you had two arrays "A",true "B",true "C",true and "A",true "B",true "D",true. Even though array one has C and array two has D there's no check that will catch that(Mentioned by @Patashu)..SO for that i have made below changes.

public boolean compareLists(List<MyData> prevList, List<MyData> modelList) {
        if (prevList!= null && modelList!=null && prevList.size() == modelList.size()) {
            boolean indicator = false;
            for (MyData modelListdata : modelList) {
                for (MyData prevListdata : prevList) {
                    if (prevListdata.getName().equals(modelListdata.getName())
                            && prevListdata.isCheck() != modelListdata.isCheck()) {
                        return  true;

                    }
                    if (modelListdata.getName().equals(prevListdata.getName())) {
                        indicator = false;
                        break;
                    } else
                        indicator = true;
                }
                }

            }
        if (indicator)
            return true;
    }
        }
        else{
            return true;
        }
        return false; 

    }

how to split the ng-repeat data with three columns using bootstrap

Here's an easy-hacky way of doing it. It's more manual and ends up with messy markup. I do not recommend this, but there are situations where this might be useful.

Here's a fiddle link http://jsfiddle.net/m0nk3y/9wcbpydq/

HTML:

<div ng-controller="myController">
    <div class="row">
        <div class="col-sm-4">
            <div class="well">
                <div ng-repeat="person in people = data | limitTo:Math.ceil(data.length/3)">
                {{ person.name }}
                </div>
            </div>
        </div>
        <div class="col-sm-4">
            <div class="well">
                <div ng-repeat="person in people = data | limitTo:Math.ceil(data.length/3):Math.ceil(data.length/3)">
                {{ person.name }}
                </div>
            </div>
        </div>
        <div class="col-sm-4">
            <div class="well">
                <div ng-repeat="person in people = data | limitTo:Math.ceil(data.length/3):Math.ceil(data.length/3)*2">
                {{ person.name }}
                </div>
            </div>
        </div>
    </div>
</div>

JS:

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

app.controller('myController', function($scope) {

    $scope.Math = Math;
    $scope.data = [
        {"name":"Person A"},
        ...
    ];
});

This setup requires us to use some Math on the markup :/, so you'll need to inject Math by adding this line: $scope.Math = Math;

Using :after to clear floating elements

No, you don't it's enough to do something like this:

<ul class="clearfix">
  <li>one</li>
  <li>two></li>
</ul>

And the following CSS:

ul li {float: left;}


.clearfix:after {
  content: ".";
  display: block;
  clear: both;
  visibility: hidden;
  line-height: 0;
  height: 0;
}

.clearfix {
  display: inline-block;
}

html[xmlns] .clearfix {
   display: block;
}

* html .clearfix {
   height: 1%;
}

Spring schemaLocation fails when there is no internet connection

If you are using eclipse for your development , it helps if you install STS plugin for Eclipse [ from the marketPlace for the specific version of eclipse .

Now When you try to create a new configuration file in a folder(normally resources) inside the project , the options would have a "Spring Folder" and you can choose a "Spring Bean Definition File " option Spring > Spring Bean Configuation File .

With this option selected , when you follow steps , it asks you to select for namespaces and the specific versions :

And so the possibility of having a non-existent jar Or old version can be eliminated .

Would have posted images as well , but my reputation is pretty low.. :(

jQuery get input value after keypress

please use this code for input text

$('#search').on("input",function (e) {});

if you use .on("change",function (e) {}); then you need to blur input

if you use .on("keyup",function (e) {}); then you get value before the last character you typed

How to execute a shell script in PHP?

You might have disabled the exec privileges, most of the LAMP packages have those disabled. Check your php.ini for this line:

disable_functions = exec

And remove the exec, shell_exec entries if there are there.

Good Luck!

Iterating through a range of dates in Python

For completeness, Pandas also has a period_range function for timestamps that are out of bounds:

import pandas as pd

pd.period_range(start='1/1/1626', end='1/08/1627', freq='D')

What's wrong with using == to compare floats in Java?

I think there is a lot of confusion around floats (and doubles), it is good to clear it up.

  1. There is nothing inherently wrong in using floats as IDs in standard-compliant JVM [*]. If you simply set the float ID to x, do nothing with it (i.e. no arithmetics) and later test for y == x, you'll be fine. Also there is nothing wrong in using them as keys in a HashMap. What you cannot do is assume equalities like x == (x - y) + y, etc. This being said, people usually use integer types as IDs, and you can observe that most people here are put off by this code, so for practical reasons, it is better to adhere to conventions. Note that there are as many different double values as there are long values, so you gain nothing by using double. Also, generating "next available ID" can be tricky with doubles and requires some knowledge of the floating-point arithmetic. Not worth the trouble.

  2. On the other hand, relying on numerical equality of the results of two mathematically equivalent computations is risky. This is because of the rounding errors and loss of precision when converting from decimal to binary representation. This has been discussed to death on SO.

[*] When I said "standard-compliant JVM" I wanted to exclude certain brain-damaged JVM implementations. See this.

How to add an onchange event to a select box via javascript?

replace:

transport_select.onChange = function(){toggleSelect(transport_select_id);};

with:

transport_select.onchange = function(){toggleSelect(transport_select_id);};

on'C'hange >> on'c'hange


You can use addEventListener too.

SQL: set existing column as Primary Key in MySQL

Go to localhost/phpmyadmin and press enter key. Now select:

database --> table_name --->Structure --->Action  ---> Primary -->click on Primary 

Assigning a function to a variable

lambda should be useful for this case. For example,

  1. create function y=x+1 y=lambda x:x+1

  2. call the function y(1) then return 2.

How to get 'System.Web.Http, Version=5.2.3.0?

Uninstalling and re-installing the NuGet package worked for me.

  1. Remove any old reference from the project.

Execute this in the Package Manager Console:

  1. UnInstall-Package Microsoft.AspNet.WebApi.Core -version 5.2.3
  2. Install-Package Microsoft.AspNet.WebApi.Core -version 5.2.3

Read environment variables in Node.js

process.env.ENV_VARIABLE

Where ENV_VARIABLE is the name of the variable you wish to access.

See Node.js docs for process.env.

How to select a node of treeview programmatically in c#?

yourNode.Toggle(); //use that function on your node, it toggles it

Mac OS X and multiple Java versions

I find this Java version manager called Jabba recently and the usage is very similar to version managers of other languages like rvm(ruby), nvm(node), pyenv(python), etc. Also it's cross platform so definitely it can be used on Mac.

After installation, it will create a dir in ~/.jabba to put all the Java versions you install. It "Supports installation of Oracle JDK (default) / Server JRE, Zulu OpenJDK (since 0.3.0), IBM SDK, Java Technology Edition (since 0.6.0) and from custom URLs.".

Basic usage is listed on their Github. A quick summary to start:

curl -sL https://github.com/shyiko/jabba/raw/master/install.sh | bash && . ~/.jabba/jabba.sh

# install Oracle JDK
jabba install 1.8 # "jabba use 1.8" will be called automatically  
jabba install 1.7 # "jabba use 1.7" will be called automatically 

# list all installed JDK's
jabba ls

# switch to a different version of JDK
jabba use 1.8

Can I set enum start value in Java?

Yes. You can pass the numerical values to the constructor for the enum, like so:

enum Ids {
  OPEN(100),
  CLOSE(200);

  private int value;    

  private Ids(int value) {
    this.value = value;
  }

  public int getValue() {
    return value;
  }
}

See the Sun Java Language Guide for more information.

Vertical Align text in a Label

This is what I usually do to "vertical align" text inside labels:

label {
   display: block;
   float: left;
   padding-top: 2px; /*This needs to be modified to fit */
}

It won't scale very nicely, but it works.

Laravel - display a PDF file in storage without forcing download?

Laravel 5.6.*

$name = 'file.jpg';

store on image or pdf

$file->storeAs('public/', $name );

download image or pdf

return response()->download($name);

view image or pdf

return response()->file($name);

Check if value exists in dataTable?

you could set the database as IEnumberable and use linq to check if the values exist. check out this link

LINQ Query on Datatable to check if record exists

the example given is

var dataRowQuery= myDataTable.AsEnumerable().Where(row => ...

you could supplement where with any

Access nested dictionary items via a list of keys?

You can make use of the eval function in python.

def nested_parse(nest, map_list):
    nestq = "nest['" + "']['".join(map_list) + "']"
    return eval(nestq, {'__builtins__':None}, {'nest':nest})

Explanation

For your example query: maplist = ["b", "v", "y"]

nestq will be "nest['b']['v']['y']" where nest is the nested dictionary.

The eval builtin function executes the given string. However, it is important to be careful about possible vulnerabilities that arise from use of eval function. Discussion can be found here:

  1. https://nedbatchelder.com/blog/201206/eval_really_is_dangerous.html
  2. https://www.journaldev.com/22504/python-eval-function

In the nested_parse() function, I have made sure that no __builtins__ globals are available and only local variable that is available is the nest dictionary.

SQLite in Android How to update a specific row

You try this one update method in SQLite

int id;
ContentValues con = new ContentValues();
con.put(TITLE, title);
con.put(AREA, area);
con.put(DESCR, desc);
con.put(TAG, tag);
myDataBase.update(TABLE, con, KEY_ID + "=" + id,null);

How to read data from java properties file using Spring Boot

I have created following class

ConfigUtility.java

@Configuration
public class ConfigUtility {

    @Autowired
    private Environment env;

    public String getProperty(String pPropertyKey) {
        return env.getProperty(pPropertyKey);
    }
} 

and called as follow to get application.properties value

myclass.java

@Autowired
private ConfigUtility configUtil;

public AppResponse getDetails() {

  AppResponse response = new AppResponse();
    String email = configUtil.getProperty("emailid");
    return response;        
}

application.properties

[email protected]

unit tested, working as expected...

What is the difference between a static and a non-static initialization code block

when a developer use an initializer block, the Java Compiler copies the initializer into each constructor of the current class.

Example:

the following code:

class MyClass {

    private int myField = 3;
    {
        myField = myField + 2;
        //myField is worth 5 for all instance
    }

    public MyClass() {
        myField = myField * 4;
        //myField is worth 20 for all instance initialized with this construtor
    }

    public MyClass(int _myParam) {
        if (_myParam > 0) {
            myField = myField * 4;
            //myField is worth 20 for all instance initialized with this construtor
            //if _myParam is greater than 0
        } else {
            myField = myField + 5;
            //myField is worth 10 for all instance initialized with this construtor
            //if _myParam is lower than 0 or if _myParam is worth 0
        }
    }

    public void setMyField(int _myField) {
        myField = _myField;
    }


    public int getMyField() {
        return myField;
    }
}

public class MainClass{

    public static void main(String[] args) {
        MyClass myFirstInstance_ = new MyClass();
        System.out.println(myFirstInstance_.getMyField());//20
        MyClass mySecondInstance_ = new MyClass(1);
        System.out.println(mySecondInstance_.getMyField());//20
        MyClass myThirdInstance_ = new MyClass(-1);
        System.out.println(myThirdInstance_.getMyField());//10
    }
}

is equivalent to:

class MyClass {

    private int myField = 3;

    public MyClass() {
        myField = myField + 2;
        myField = myField * 4;
        //myField is worth 20 for all instance initialized with this construtor
    }

    public MyClass(int _myParam) {
        myField = myField + 2;
        if (_myParam > 0) {
            myField = myField * 4;
            //myField is worth 20 for all instance initialized with this construtor
            //if _myParam is greater than 0
        } else {
            myField = myField + 5;
            //myField is worth 10 for all instance initialized with this construtor
            //if _myParam is lower than 0 or if _myParam is worth 0
        }
    }

    public void setMyField(int _myField) {
        myField = _myField;
    }


    public int getMyField() {
        return myField;
    }
}

public class MainClass{

    public static void main(String[] args) {
        MyClass myFirstInstance_ = new MyClass();
        System.out.println(myFirstInstance_.getMyField());//20
        MyClass mySecondInstance_ = new MyClass(1);
        System.out.println(mySecondInstance_.getMyField());//20
        MyClass myThirdInstance_ = new MyClass(-1);
        System.out.println(myThirdInstance_.getMyField());//10
    }
}

I hope my example is understood by developers.

Use CASE statement to check if column exists in table - SQL Server

Final answer was a combination of two of the above (I've upvoted both to show my appreciation!):

select case 
   when exists (
      SELECT 1 
      FROM Sys.columns c 
      WHERE c.[object_id] = OBJECT_ID('dbo.Tags') 
         AND c.name = 'ModifiedByUserId'
   ) 
   then 1 
   else 0 
end

how to check if a datareader is null or empty

I also experiencing this kind of problem but mine, i'm using DbDataReader as my generic reader (for SQL, Oracle, OleDb, etc.). If using DataTable, DataTable has this method:

DataTable dt = new DataTable();
dt.Rows[0].Table.Columns.Contains("SampleColumn");

using this I can determine if that column is existing in the result set that my query has. I'm also looking if DbDataReader has this capability.

Git Pull While Ignoring Local Changes?

You just want a command which gives exactly the same result as rm -rf local_repo && git clone remote_url, right? I also want this feature. I wonder why git does not provide such a command (such as git reclone or git sync), neither does svn provide such a command (such as svn recheckout or svn sync).

Try the following command:

git reset --hard origin/master
git clean -fxd
git pull

How to get the file-path of the currently executing javascript code

All browsers except Internet Explorer (any version) have document.currentScript, which always works always (no matter how the file was included (async, bookmarklet etc)).

If you want to know the full URL of the JS file you're in right now:

var script = document.currentScript;
var fullUrl = script.src;

Tadaa.

What does it mean "No Launcher activity found!"

Like Gusdor said above, "Multiple action tags in a single intent-filter tag will also cause the same error." (Give him the credit! I could just kiss Gusdor for this!)
I didn't find any docs for this fact! I had added a new (USB) action and being clever, I lumped it in the same intent-filter. And it broke the launch. Like Gusdor said, one intent filter, one action! Apparently each action should go in its own intent filter.
It should look like this...

<intent-filter>
  <action android:name="android.intent.action.MAIN" />
  <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
  <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
</intent-filter>

When I did this, WAZOO! it worked!

Android Emulator: Installation error: INSTALL_FAILED_VERSION_DOWNGRADE

It means you're trying to install an app with the same packageName as an app that's already installed on the emulator, but the one you're trying to install has a lower versionCode (integer value for your version number).

You might have installed from a separate copy of the code where the version number was higher than the copy you're working with right now. In either case, either:

  • uninstall the currently installed copy

  • or open up your phone's Settings > Application Manager to determine the version number for the installed app, and increment your <manifest android:versionCode to be higher in the AndroidManifest.

  • or https://stackoverflow.com/a/13772620/632951

How to deal with bad_alloc in C++?

You can catch it like any other exception:

try {
  foo();
}
catch (const std::bad_alloc&) {
  return -1;
}

Quite what you can usefully do from this point is up to you, but it's definitely feasible technically.



In general you cannot, and should not try, to respond to this error. bad_alloc indicates that a resource cannot be allocated because not enough memory is available. In most scenarios your program cannot hope to cope with that, and terminating soon is the only meaningful behaviour.

Worse, modern operating systems often over-allocate: on such systems, malloc and new can return a valid pointer even if there is not enough free memory left – std::bad_alloc will never be thrown, or is at least not a reliable sign of memory exhaustion. Instead, attempts to access the allocated memory will then result in a segmentation fault, which is not catchable (you can handle the segmentation fault signal, but you cannot resume the program afterwards).

The only thing you could do when catching std::bad_alloc is to perhaps log the error, and try to ensure a safe program termination by freeing outstanding resources (but this is done automatically in the normal course of stack unwinding after the error gets thrown if the program uses RAII appropriately).

In certain cases, the program may attempt to free some memory and try again, or use secondary memory (= disk) instead of RAM but these opportunities only exist in very specific scenarios with strict conditions:

  1. The application must ensure that it runs on a system that does not overcommit memory, i.e. it signals failure upon allocation rather than later.
  2. The application must be able to free memory immediately, without any further accidental allocations in the meantime.

It’s exceedingly rare that applications have control over point 1 — userspace applications never do, it’s a system-wide setting that requires root permissions to change.1

OK, so let’s assume you’ve fixed point 1. What you can now do is for instance use a LRU cache for some of your data (probably some particularly large business objects that can be regenerated or reloaded on demand). Next, you need to put the actual logic that may fail into a function that supports retry — in other words, if it gets aborted, you can just relaunch it:

lru_cache<widget> widget_cache;

double perform_operation(int widget_id) {
    std::optional<widget> maybe_widget = widget_cache.find_by_id(widget_id);
    if (not maybe_widget) {
        maybe_widget = widget_cache.store(widget_id, load_widget_from_disk(widget_id));
    }
    return maybe_widget->frobnicate();
}

…

for (int num_attempts = 0; num_attempts < MAX_NUM_ATTEMPTS; ++num_attempts) {
    try {
        return perform_operation(widget_id);
    } catch (std::bad_alloc const&) {
        if (widget_cache.empty()) throw; // memory error elsewhere.
        widget_cache.remove_oldest();
    }
}

// Handle too many failed attempts here.

But even here, using std::set_new_handler instead of handling std::bad_alloc provides the same benefit and would be much simpler.


1 If you’re creating an application that does control point 1, and you’re reading this answer, please shoot me an email, I’m genuinely curious about your circumstances.


What is the C++ Standard specified behavior of new in c++?

The usual notion is that if new operator cannot allocate dynamic memory of the requested size, then it should throw an exception of type std::bad_alloc.
However, something more happens even before a bad_alloc exception is thrown:

C++03 Section 3.7.4.1.3: says

An allocation function that fails to allocate storage can invoke the currently installed new_handler(18.4.2.2), if any. [Note: A program-supplied allocation function can obtain the address of the currently installed new_handler using the set_new_handler function (18.4.2.3).] If an allocation function declared with an empty exception-specification (15.4), throw(), fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall only indicate failure by throw-ing an exception of class std::bad_alloc (18.4.2.1) or a class derived from std::bad_alloc.

Consider the following code sample:

#include <iostream>
#include <cstdlib>

// function to call if operator new can't allocate enough memory or error arises
void outOfMemHandler()
{
    std::cerr << "Unable to satisfy request for memory\n";

    std::abort();
}

int main()
{
    //set the new_handler
    std::set_new_handler(outOfMemHandler);

    //Request huge memory size, that will cause ::operator new to fail
    int *pBigDataArray = new int[100000000L];

    return 0;
}

In the above example, operator new (most likely) will be unable to allocate space for 100,000,000 integers, and the function outOfMemHandler() will be called, and the program will abort after issuing an error message.

As seen here the default behavior of new operator when unable to fulfill a memory request, is to call the new-handler function repeatedly until it can find enough memory or there is no more new handlers. In the above example, unless we call std::abort(), outOfMemHandler() would be called repeatedly. Therefore, the handler should either ensure that the next allocation succeeds, or register another handler, or register no handler, or not return (i.e. terminate the program). If there is no new handler and the allocation fails, the operator will throw an exception.

What is the new_handler and set_new_handler?

new_handler is a typedef for a pointer to a function that takes and returns nothing, and set_new_handler is a function that takes and returns a new_handler.

Something like:

typedef void (*new_handler)();
new_handler set_new_handler(new_handler p) throw();

set_new_handler's parameter is a pointer to the function operator new should call if it can't allocate the requested memory. Its return value is a pointer to the previously registered handler function, or null if there was no previous handler.

How to handle out of memory conditions in C++?

Given the behavior of newa well designed user program should handle out of memory conditions by providing a proper new_handlerwhich does one of the following:

Make more memory available: This may allow the next memory allocation attempt inside operator new's loop to succeed. One way to implement this is to allocate a large block of memory at program start-up, then release it for use in the program the first time the new-handler is invoked.

Install a different new-handler: If the current new-handler can't make any more memory available, and of there is another new-handler that can, then the current new-handler can install the other new-handler in its place (by calling set_new_handler). The next time operator new calls the new-handler function, it will get the one most recently installed.

(A variation on this theme is for a new-handler to modify its own behavior, so the next time it's invoked, it does something different. One way to achieve this is to have the new-handler modify static, namespace-specific, or global data that affects the new-handler's behavior.)

Uninstall the new-handler: This is done by passing a null pointer to set_new_handler. With no new-handler installed, operator new will throw an exception ((convertible to) std::bad_alloc) when memory allocation is unsuccessful.

Throw an exception convertible to std::bad_alloc. Such exceptions are not be caught by operator new, but will propagate to the site originating the request for memory.

Not return: By calling abort or exit.

What is the purpose of flush() in Java streams?

When you write data to a stream, it is not written immediately, and it is buffered. So use flush() when you need to be sure that all your data from buffer is written.

We need to be sure that all the writes are completed before we close the stream, and that is why flush() is called in file/buffered writer's close().

But if you have a requirement that all your writes be saved anytime before you close the stream, use flush().

Android RecyclerView addition & removal of items

The Problem

RecyclerView is, by default, unaware of your dataset changes. This means that whenever you make a deletion/addition on your data list, those changes won't be reflected to your RecyclerView directly. (i.e. you remove the item at index 5, but the 6th element remains in your recycler view).

A "ok" Solution

RecyclerView exposes some methods for you to communicate your dataset changes, reflecting those changes directly on your list items. The standard Android APIs allow you to bind the process of data removal (for the purpose of the question) with the process of View removal.

The methods we talked about are:

notifyItemChanged(index: Int)
notifyItemInserted(index: Int)
notifyItemRemoved(index: Int)
notifyItemRangeChanged(startPosition: Int, itemCount: Int)
notifyItemRangeInserted(startPosition: Int, itemCount: Int)
notifyItemRangeRemoved(startPosition: Int, itemCount: Int)

Better Solution

If you don't properly specify what happens on each addition, change or removal of items, RecyclerView children are animated unresponsively because of a lack of information about how to move the different views around the list.

Instead, the following code will precisely play the animation, just on the child that is being removed (And as a side note, it fixed any IndexOutOfBoundExceptions, marked by the stacktrace as "data inconsistency").

void remove(position: Int) {
    dataset.removeAt(position)
    notifyItemChanged(position)
    notifyItemRangeRemoved(position, 1)
}

Under the hood, if we look into RecyclerView we can find documentation explaining that the second parameter we pass to notifyItemRangeRemoved is the number of items that are removed from the dataset, not the total number of items (As wrongly reported in some others information sources).

    /**
     * Notify any registered observers that the <code>itemCount</code> items previously
     * located at <code>positionStart</code> have been removed from the data set. The items
     * previously located at and after <code>positionStart + itemCount</code> may now be found
     * at <code>oldPosition - itemCount</code>.
     *
     * <p>This is a structural change event. Representations of other existing items in the data
     * set are still considered up to date and will not be rebound, though their positions
     * may be altered.</p>
     *
     * @param positionStart Previous position of the first item that was removed
     * @param itemCount Number of items removed from the data set
     */
    public final void notifyItemRangeRemoved(int positionStart, int itemCount) {
        mObservable.notifyItemRangeRemoved(positionStart, itemCount);
    }

Even Better Solution (Opinionated)

Do not use any of those functions. That's my personal view. They are counterintuitive, error-prone and they feel really verbose and unnecessary. Let a library like FastAdapter, Epoxy or Groupie take care of this business, or use an observable recycler view with data binding.

Python `if x is not None` or `if not x is None`?

Python if x is not None or if not x is None?

TLDR: The bytecode compiler parses them both to x is not None - so for readability's sake, use if x is not None.

Readability

We use Python because we value things like human readability, useability, and correctness of various paradigms of programming over performance.

Python optimizes for readability, especially in this context.

Parsing and Compiling the Bytecode

The not binds more weakly than is, so there is no logical difference here. See the documentation:

The operators is and is not test for object identity: x is y is true if and only if x and y are the same object. x is not y yields the inverse truth value.

The is not is specifically provided for in the Python grammar as a readability improvement for the language:

comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'

And so it is a unitary element of the grammar as well.

Of course, it is not parsed the same:

>>> import ast
>>> ast.dump(ast.parse('x is not None').body[0].value)
"Compare(left=Name(id='x', ctx=Load()), ops=[IsNot()], comparators=[Name(id='None', ctx=Load())])"
>>> ast.dump(ast.parse('not x is None').body[0].value)
"UnaryOp(op=Not(), operand=Compare(left=Name(id='x', ctx=Load()), ops=[Is()], comparators=[Name(id='None', ctx=Load())]))"

But then the byte compiler will actually translate the not ... is to is not:

>>> import dis
>>> dis.dis(lambda x, y: x is not y)
  1           0 LOAD_FAST                0 (x)
              3 LOAD_FAST                1 (y)
              6 COMPARE_OP               9 (is not)
              9 RETURN_VALUE
>>> dis.dis(lambda x, y: not x is y)
  1           0 LOAD_FAST                0 (x)
              3 LOAD_FAST                1 (y)
              6 COMPARE_OP               9 (is not)
              9 RETURN_VALUE

So for the sake of readability and using the language as it was intended, please use is not.

To not use it is not wise.

len() of a numpy array in python

What is the len of the equivalent nested list?

len([[2,3,1,0], [2,3,1,0], [3,2,1,1]])

With the more general concept of shape, numpy developers choose to implement __len__ as the first dimension. Python maps len(obj) onto obj.__len__.

X.shape returns a tuple, which does have a len - which is the number of dimensions, X.ndim. X.shape[i] selects the ith dimension (a straight forward application of tuple indexing).

stale element reference: element is not attached to the page document

Use this code:

public class LinkTest 
{   
    public static void main(String[] args) 
    {
        WebDriver driver = new FirefoxDriver();
        driver.navigate().to("file:///C:/Users/vkiran/Desktop/xyz.html");
        List<WebElement> alllinks =driver.findElements(By.xpath("//*[@id='sliding-navigation']//a"));
        String a[]=new String[alllinks.size()];
        for(int i=0;i<alllinks.size();i++)
        {
            a[i]=alllinks.get(i).getText(); 
            if(a[i].startsWith("B"))
            {
                System.out.println("clicking on this link::"+driver.findElement(By.linkText(a[i])).getText());
                driver.findElement(By.linkText(a[i])).click();  

            }
            else
            {
                System.out.println("does not starts with B so not clicking");
            }
        }
}
}

How to replace NA values in a table for selected columns

Not sure if this is more concise, but this function will also find and allow replacement of NAs (or any value you like) in selected columns of a data.table:

update.mat <- function(dt, cols, criteria) {
  require(data.table)
  x <- as.data.frame(which(criteria==TRUE, arr.ind = TRUE))
  y <- as.matrix(subset(x, x$col %in% which((names(dt) %in% cols), arr.ind = TRUE)))
  y
}

To apply it:

y[update.mat(y, c("a", "b"), is.na(y))] <- 0

The function creates a matrix of the selected columns and rows (cell coordinates) that meet the input criteria (in this case is.na == TRUE).

Cluster analysis in R: determine the optimal number of clusters

These methods are great but when trying to find k for much larger data sets, these can be crazy slow in R.

A good solution I have found is the "RWeka" package, which has an efficient implementation of the X-Means algorithm - an extended version of K-Means that scales better and will determine the optimum number of clusters for you.

First you'll want to make sure that Weka is installed on your system and have XMeans installed through Weka's package manager tool.

library(RWeka)

# Print a list of available options for the X-Means algorithm
WOW("XMeans")

# Create a Weka_control object which will specify our parameters
weka_ctrl <- Weka_control(
    I = 1000,                          # max no. of overall iterations
    M = 1000,                          # max no. of iterations in the kMeans loop
    L = 20,                            # min no. of clusters
    H = 150,                           # max no. of clusters
    D = "weka.core.EuclideanDistance", # distance metric Euclidean
    C = 0.4,                           # cutoff factor ???
    S = 12                             # random number seed (for reproducibility)
)

# Run the algorithm on your data, d
x_means <- XMeans(d, control = weka_ctrl)

# Assign cluster IDs to original data set
d$xmeans.cluster <- x_means$class_ids

How to square or raise to a power (elementwise) a 2D numpy array?

The fastest way is to do a*a or a**2 or np.square(a) whereas np.power(a, 2) showed to be considerably slower.

np.power() allows you to use different exponents for each element if instead of 2 you pass another array of exponents. From the comments of @GarethRees I just learned that this function will give you different results than a**2 or a*a, which become important in cases where you have small tolerances.

I've timed some examples using NumPy 1.9.0 MKL 64 bit, and the results are shown below:

In [29]: a = np.random.random((1000, 1000))

In [30]: timeit a*a
100 loops, best of 3: 2.78 ms per loop

In [31]: timeit a**2
100 loops, best of 3: 2.77 ms per loop

In [32]: timeit np.power(a, 2)
10 loops, best of 3: 71.3 ms per loop

How do I format a string using a dictionary in python-3.x?

The Python 2 syntax works in Python 3 as well:

>>> class MyClass:
...     def __init__(self):
...         self.title = 'Title'
... 
>>> a = MyClass()
>>> print('The title is %(title)s' % a.__dict__)
The title is Title
>>> 
>>> path = '/path/to/a/file'
>>> print('You put your file here: %(path)s' % locals())
You put your file here: /path/to/a/file

How to set java_home on Windows 7?

In cmd (temporarily for that cmd window):

set JAVA_HOME="C:\\....\java\jdk1.x.y_zz"

echo %JAVA_HOME%

set PATH=%PATH%;%JAVA_HOME%\bin

echo %PATH%

Parsing PDF files (especially with tables) with PDFBox

Extracting data from PDF is bound to be fraught with problems. Are the documents created through some kind of automatic process? If so, you might consider converting the PDFs to uncompressed PostScript (try pdf2ps) and seeing if the PostScript contains some sort of regular pattern which you can exploit.

How do I check OS with a preprocessor directive?

You can use pre-processor directives as warning or error to check at compile time you don't need to run this program at all just simply compile it .

#if defined(_WIN32) || defined(_WIN64) || defined(__WINDOWS__)
    #error Windows_OS
#elif defined(__linux__)
    #error Linux_OS
#elif defined(__APPLE__) && defined(__MACH__)
    #error Mach_OS
#elif defined(unix) || defined(__unix__) || defined(__unix)
    #error Unix_OS
#else
    #error Unknown_OS
#endif

#include <stdio.h>
int main(void)
{
    return 0;
}

Select datatype of the field in postgres

Pulling data type from information_schema is possible, but not convenient (requires joining several columns with a case statement). Alternatively one can use format_type built-in function to do that, but it works on internal type identifiers that are visible in pg_attribute but not in information_schema. Example

SELECT a.attname as column_name, format_type(a.atttypid, a.atttypmod) AS data_type
FROM pg_attribute a JOIN pg_class b ON a.attrelid = b.relfilenode
WHERE a.attnum > 0 -- hide internal columns
AND NOT a.attisdropped -- hide deleted columns
AND b.oid = 'my_table'::regclass::oid; -- example way to find pg_class entry for a table

Based on https://gis.stackexchange.com/a/97834.

Why am I getting "undefined reference to sqrt" error even though I include math.h header?

This is a likely a linker error. Add the -lm switch to specify that you want to link against the standard C math library (libm) which has the definition for those functions (the header just has the declaration for them - worth looking up the difference.)

How to set timeout for a line of c# code

I use something like this (you should add code to deal with the various fails):

    var response = RunTaskWithTimeout<ReturnType>(
        (Func<ReturnType>)delegate { return SomeMethod(someInput); }, 30);


    /// <summary>
    /// Generic method to run a task on a background thread with a specific timeout, if the task fails,
    /// notifies a user
    /// </summary>
    /// <typeparam name="T">Return type of function</typeparam>
    /// <param name="TaskAction">Function delegate for task to perform</param>
    /// <param name="TimeoutSeconds">Time to allow before task times out</param>
    /// <returns></returns>
    private T RunTaskWithTimeout<T>(Func<T> TaskAction, int TimeoutSeconds)
    {
        Task<T> backgroundTask;

        try
        {
            backgroundTask = Task.Factory.StartNew(TaskAction);
            backgroundTask.Wait(new TimeSpan(0, 0, TimeoutSeconds));
        }
        catch (AggregateException ex)
        {
            // task failed
            var failMessage = ex.Flatten().InnerException.Message);
            return default(T);
        }
        catch (Exception ex)
        {
            // task failed
            var failMessage = ex.Message;
            return default(T);
        }

        if (!backgroundTask.IsCompleted)
        {
            // task timed out
            return default(T);
        }

        // task succeeded
        return backgroundTask.Result;
    }

C++ float array initialization

No, it sets all members/elements that haven't been explicitly set to their default-initialisation value, which is zero for numeric types.

Installing Oracle Instant Client

I was able to setup Oracle Instant Client (Basic) 11g2 and Oracle ODBC (32bit) drivers on my 32bit Windows 7 PC. Note: you'll need a 'tnsnames.ora' file because it doesn't come with one. You can Google examples and copy/paste into a text file, change the parameters for your environment.

Setting up Oracle Instant Client-Basic 11g2 (Win7 32-bit)
(I think there's another step or two if your using 64-bit)

Oracle Instant Client

  • Unzip Oracle Instant Client - Basic
  • Put contents in folder like "C:\instantclient"
  • Edit PATH evironment variable, add path to Instant Client folder to the Variable Value.
  • Add new Variable called "TNS_ADMIN" point to same folder as Instant Client.
  • I had to create a "tnsnames.ora" file because it doesn't come with one. Put it in same folder as the client.
  • reboot or use Task Manager to kill "explorer.exe" and restart it to refresh the PATH environment variables.

ODBC Drivers

  • Unzip ODBC drivers
  • Copy all files into same folder as client "C:\instantclient"
  • Use command prompt to run "odbc_install.exe" (should say it was successful)

Note: The "un-documented" things that were hanging me up where...
- All files (Client and Drivers) needed to be in the same folder (nothing in sub-folders).
- Running the ODBC driver from the command prompt will allow you to see if it installs successfully. Double-clicking the installer just flashed a box on the screen, no idea it was failing because no error dialog.

After you've done this you should be able to setup a new DSN Data Source using the Oracle ODBC driver.
-Hope this helps someone else.

Call PHP function from jQuery?

AJAX does the magic:

$(document).ready(function(

    $.ajax({ url: 'script.php?argument=value&foo=bar' });

));

Google Play Services GCM 9.2.0 asks to "update" back to 9.0.0

Just put this line at the bottom of your app-module's (not project root's) gradle file.

apply plugin: 'com.google.gms.google-services'

Then rebuild your project.

How can I see the size of files and directories in linux?

du -sh [file_name]

works perfectly to get size of a particular file.

HTML table with horizontal scrolling (first column fixed)

Based on skube's approach, I found the minimal set of CSS I needed was:

_x000D_
_x000D_
.horizontal-scroll-except-first-column {_x000D_
  width: 100%;_x000D_
  overflow: auto;_x000D_
}_x000D_
_x000D_
.horizontal-scroll-except-first-column > table {_x000D_
  margin-left: 8em;_x000D_
}_x000D_
_x000D_
.horizontal-scroll-except-first-column > table > * > tr > th:first-child,_x000D_
.horizontal-scroll-except-first-column > table > * > tr > td:first-child {_x000D_
  position: absolute;_x000D_
  width: 8em;_x000D_
  margin-left: -8em;_x000D_
  background: #ccc;_x000D_
}_x000D_
_x000D_
.horizontal-scroll-except-first-column > table > * > tr > th,_x000D_
.horizontal-scroll-except-first-column > table > * > tr > td {_x000D_
  /* Without this, if a cell wraps onto two lines, the first column_x000D_
   * will look bad, and may need padding. */_x000D_
  white-space: nowrap;_x000D_
}
_x000D_
<div class="horizontal-scroll-except-first-column">_x000D_
  <table>_x000D_
    <tbody>_x000D_
      <tr>_x000D_
        <td>FIXED</td> <td>22222</td> <td>33333</td> <td>44444</td> <td>55555</td> <td>66666</td> <td>77777</td> <td>88888</td> <td>99999</td> <td>AAAAA</td> <td>BBBBB</td> <td>CCCCC</td> <td>DDDDD</td> <td>EEEEE</td> <td>FFFFF</td>_x000D_
      </tr>_x000D_
    </tbody>_x000D_
  </table>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Use SQL Server Management Studio to connect remotely to an SQL Server Express instance hosted on an Azure Virtual Machine

The fact that you're getting an error from the Names Pipes Provider tells us that you're not using the TCP/IP protocol when you're trying to establish the connection. Try adding the "tcp" prefix and specifying the port number:

tcp:name.cloudapp.net,1433

Lombok added but getters and setters not recognized in Intellij IDEA

  1. Go to File > Settings > Plugins.
    1. Click on Browse repositories...
    2. Search for Lombok Plugin.
    3. Click on Install plugin.
    4. Restart Android Studio.

Automatically open Chrome developer tools when new tab/new window is opened

Under the Chrome DevTools settings you enable:

Under Network -> Preserve Log Under DevTools -> Auto-open DevTools for popups

how to draw directed graphs using networkx in python?

import networkx as nx
import matplotlib.pyplot as plt

g = nx.DiGraph()
g.add_nodes_from([1,2,3,4,5])
g.add_edge(1,2)
g.add_edge(4,2)
g.add_edge(3,5)
g.add_edge(2,3)
g.add_edge(5,4)

nx.draw(g,with_labels=True)
plt.draw()
plt.show()

This is just simple how to draw directed graph using python 3.x using networkx. just simple representation and can be modified and colored etc. See the generated graph here.

Note: It's just a simple representation. Weighted Edges could be added like

g.add_edges_from([(1,2),(2,5)], weight=2)

and hence plotted again.

Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved

I faced the same problem but it resolved with some changes in setting.xml(.*\apache-maven-3.3.3\apache-maven-3.3.3\conf).

  <proxies>
  <proxy>
    <id>proxy</id>
    <active>true</active>
    <protocol>http</protocol>
    <host>HOSTNAME</host>
    <port>PORT</port>
  </proxy>
</proxies>

Just check the hostname and port from the IE setting -> connections -> LAN Setting -> Proxy server

Hope this will resolve your problem also :)

How to redirect to the same page in PHP

Another elegant one is

header("Location: http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]");
exit;

Javascript Equivalent to C# LINQ Select

Take a look at fluent, it supports almost everything LINQ does and based on iterables - so it works with maps, generator functions, arrays, everything iterable.

Mockito: InvalidUseOfMatchersException

Do not use Mockito.anyXXXX(). Directly pass the value to the method parameter of same type. Example:

A expected = new A(10);

String firstId = "10w";
String secondId = "20s";
String product = "Test";
String type = "type2";
Mockito.when(service.getTestData(firstId, secondId, product,type)).thenReturn(expected);

public class A{
   int a ;
   public A(int a) {
      this.a = a;
   }
}

How to remove listview all items

For me worked this way:

private ListView yourListViewName;
private List<YourClassName> yourListName;

  ...

yourListName = new ArrayList<>();
yourAdapterName = new yourAdapterName(this, R.layout.your_layout_name, yourListName);

  ...

if (yourAdapterName.getCount() > 0) {
   yourAdapterName.clear();
   yourAdapterName.notifyDataSetChanged();
}

yourAdapterName.add(new YourClassName(yourParameter1, yourParameter2, ...));
yourListViewName.setAdapter(yourAdapterName);

How to save username and password with Mercurial?

No one mentioned the keyring extension. It will save the username and password into the system keyring, which is far more secure than storing your passwords in a static file as mentioned above. Perform the steps below and you should be good to go. I had this up and running on Ubuntu in about 2 minutes.

>> sudo apt-get install python-pip
>> sudo pip install keyring
>> sudo pip install mercurial_keyring

**Edit your .hgrc file to include the extension**
[extensions]
mercurial_keyring = 

https://www.mercurial-scm.org/wiki/KeyringExtension

Chrome says my extension's manifest file is missing or unreadable

Mine also was funny. While copypasting " manifest.json" from the tutorial, i also managed to copy a leading space. Couldn't get why it's not finding it.

How can I refresh or reload the JFrame?

Here's a short code that might help.

    <yourJFrameName> main = new <yourJFrameName>();    

    main.setVisible(true);
    this.dispose();

where...

main.setVisible(true);

will run the JFrame again.

this.dispose();

will terminate the running window.

A default document is not configured for the requested URL, and directory browsing is not enabled on the server

I faced the same error posted by OP while trying to debug my ASP.NET website using IIS Express server. IIS Express is used by Visual Studio to run the website when we press F5.

Open solution explorer in Visual Studio -> Expand the web application project node (StudentInfo in my case) -> Right click on the web page which you want to get loaded when your website starts(StudentPortal.aspx in my case) -> Select Set as Start Page option from the context menu as shown below. It started to work from the next run.

enter image description here

Root cause: I concluded that the start page which is the default document for the website wasn't set correctly or had got messed up somehow during development.

How to get all Errors from ASP.Net MVC modelState?

During debugging I find it useful to put a table at the bottom of each of my pages to show all ModelState errors.

<table class="model-state">
    @foreach (var item in ViewContext.ViewData.ModelState) 
    {
        if (item.Value.Errors.Any())
        { 
        <tr>
            <td><b>@item.Key</b></td>
            <td>@((item.Value == null || item.Value.Value == null) ? "<null>" : item.Value.Value.RawValue)</td>
            <td>@(string.Join("; ", item.Value.Errors.Select(x => x.ErrorMessage)))</td>
        </tr>
        }
    }
</table>

<style>
    table.model-state
    {
        border-color: #600;
        border-width: 0 0 1px 1px;
        border-style: solid;
        border-collapse: collapse;
        font-size: .8em;
        font-family: arial;
    }

    table.model-state td
    {
        border-color: #600;
        border-width: 1px 1px 0 0;
        border-style: solid;
        margin: 0;
        padding: .25em .75em;
        background-color: #FFC;
    }
 </style>

Find everything between two XML tags with RegEx

this can capture most outermost layer pair of tags, even with attribute in side or without end tags

(<!--((?!-->).)*-->|<\w*((?!\/<).)*\/>|<(?<tag>\w+)[^>]*>(?>[^<]|(?R))*<\/\k<tag>\s*>)

edit: as mentioned in comment above, regex is always not enough to parse xml, trying to modify the regex to fit more situation only makes it longer but still useless

Align <div> elements side by side

_x000D_
_x000D_
.section {
  display: flex;
}

.element-left {
  width: 94%;
}

.element-right {
  flex-grow: 1;
}
_x000D_
<div class="section">
  <div id="dB" class="element-left" }>
    <a href="http://notareallink.com" title="Download" id="buyButton">Download</a>
  </div>
  <div id="gB" class="element-right">
    <a href="#" title="Gallery" onclick="$j('#galleryDiv').toggle('slow');return false;" id="galleryButton">Gallery</a>
  </div>
</div>
_x000D_
_x000D_
_x000D_

or

_x000D_
_x000D_
.section {
  display: flex;
  flex-wrap: wrap;
}

.element-left {
  flex: 2;
}

.element-right {
  width: 100px;
}
_x000D_
<div class="section">
  <div id="dB" class="element-left" }>
    <a href="http://notareallink.com" title="Download" id="buyButton">Download</a>
  </div>
  <div id="gB" class="element-right">
    <a href="#" title="Gallery" onclick="$j('#galleryDiv').toggle('slow');return false;" id="galleryButton">Gallery</a>
  </div>
</div>
_x000D_
_x000D_
_x000D_

Mergesort with Python

As already said, l.pop(0) is a O(len(l)) operation and must be avoided, the above msort function is O(n**2). If efficiency matter, indexing is better but have cost too. The for x in l is faster but not easy to implement for mergesort : iter can be used instead here. Finally, checking i < len(l) is made twice because tested again when accessing the element : the exception mechanism (try except) is better and give a last improvement of 30% .

def msort(l):
    if len(l)>1:
        t=len(l)//2
        it1=iter(msort(l[:t]));x1=next(it1)
        it2=iter(msort(l[t:]));x2=next(it2)
        l=[]
        try:
            while True:
                if x1<=x2: l.append(x1);x1=next(it1)
                else     : l.append(x2);x2=next(it2)
        except:
            if x1<=x2: l.append(x2);l.extend(it2)
            else:      l.append(x1);l.extend(it1)
    return l

How to pass in parameters when use resource service?

I think I see your problem, you need to use the @ syntax to define parameters you will pass in this way, also I'm not sure what loginID or password are doing you don't seem to define them anywhere and they are not being used as URL parameters so are they being sent as query parameters?

This is what I can suggest based on what I see so far:

.factory('MagComments', function ($resource) {
    return $resource('http://localhost/dooleystand/ci/api/magCommenct/:id', {
      loginID : organEntity,
      password : organCommpassword,
      id : '@magId'
    });
  })

The @magId string will tell the resource to replace :id with the property magId on the object you pass it as parameters.

I'd suggest reading over the documentation here (I know it's a bit opaque) very carefully and looking at the examples towards the end, this should help a lot.

Angular directives - when and how to use compile, controller, pre-link and post-link

In which order the directive functions are executed?

For a single directive

Based on the following plunk, consider the following HTML markup:

<body>
    <div log='some-div'></div>
</body>

With the following directive declaration:

myApp.directive('log', function() {
  
    return {
        controller: function( $scope, $element, $attrs, $transclude ) {
            console.log( $attrs.log + ' (controller)' );
        },
        compile: function compile( tElement, tAttributes ) {
            console.log( tAttributes.log + ' (compile)'  );
            return {
                pre: function preLink( scope, element, attributes ) {
                    console.log( attributes.log + ' (pre-link)'  );
                },
                post: function postLink( scope, element, attributes ) {
                    console.log( attributes.log + ' (post-link)'  );
                }
            };
         }
     };  
     
});

The console output will be:

some-div (compile)
some-div (controller)
some-div (pre-link)
some-div (post-link)

We can see that compile is executed first, then controller, then pre-link and last is post-link.

For nested directives

Note: The following does not apply to directives that render their children in their link function. Quite a few Angular directives do so (like ngIf, ngRepeat, or any directive with transclude). These directives will natively have their link function called before their child directives compile is called.

The original HTML markup is often made of nested elements, each with its own directive. Like in the following markup (see plunk):

<body>
    <div log='parent'>
        <div log='..first-child'></div>
        <div log='..second-child'></div>
    </div>
</body>

The console output will look like this:

// The compile phase
parent (compile)
..first-child (compile)
..second-child (compile)

// The link phase   
parent (controller)
parent (pre-link)
..first-child (controller)
..first-child (pre-link)
..first-child (post-link)
..second-child (controller)
..second-child (pre-link)
..second-child (post-link)
parent (post-link)

We can distinguish two phases here - the compile phase and the link phase.

The compile phase

When the DOM is loaded Angular starts the compile phase, where it traverses the markup top-down, and calls compile on all directives. Graphically, we could express it like so:

An image illustrating the compilation loop for children

It is perhaps important to mention that at this stage, the templates the compile function gets are the source templates (not instance template).

The link phase

DOM instances are often simply the result of a source template being rendered to the DOM, but they may be created by ng-repeat, or introduced on the fly.

Whenever a new instance of an element with a directive is rendered to the DOM, the link phase starts.

In this phase, Angular calls controller, pre-link, iterates children, and call post-link on all directives, like so:

An illustration demonstrating the link phase steps

How to change the project in GCP using CLI commands

I do prefer aliases, and for things that might need multiple commands, based on your project needs, I prefer functions...

Example

function switchGCPProject() {
        gcloud config set project [Project Name]
        // if you are using GKE use the following
        gcloud config set container/cluster [Cluster Name]
        // if you are using GCE use the following
        gcloud config set compute/zone [Zone]
        gcloud config set compute/region [region]
        // if you are using GKE use the following
        gcloud container clusters get-credentials [cluster name] --zone [Zone] --project [project name]
        export GOOGLE_APPLICATION_CREDENTIALS=path-to-credentials.json
}

How can I concatenate strings in VBA?

& is always evaluated in a string context, while + may not concatenate if one of the operands is no string:

"1" + "2" => "12"
"1" + 2   => 3
1 + "2"   => 3
"a" + 2   => type mismatch

This is simply a subtle source of potential bugs and therefore should be avoided. & always means "string concatenation", even if its arguments are non-strings:

"1" & "2" => "12"
"1" &  2  => "12"
 1  & "2" => "12"
 1  &  2  => "12"
"a" &  2  => "a2"

In Oracle, is it possible to INSERT or UPDATE a record through a view?

Oracle has two different ways of making views updatable:-

  1. The view is "key preserved" with respect to what you are trying to update. This means the primary key of the underlying table is in the view and the row appears only once in the view. This means Oracle can figure out exactly which underlying table row to update OR
  2. You write an instead of trigger.

I would stay away from instead-of triggers and get your code to update the underlying tables directly rather than through the view.

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression

Just save the string to a temp variable and then use that in your expression:

var strItem = item.Key.ToString();

IQueryable<entity> pages = from p in context.pages
                           where  p.Serial == strItem
                           select p;

The problem arises because ToString() isn't really executed, it is turned into a MethodGroup and then parsed and translated to SQL. Since there is no ToString() equivalent, the expression fails.

Note:

Make sure you also check out Alex's answer regarding the SqlFunctions helper class that was added later. In many cases it can eliminate the need for the temporary variable.

MySQL does not start when upgrading OSX to Yosemite or El Capitan

you want fix it can edit file "/Applications/XAMPP/xamppfiles/xampp" with TextEdit.

Look for text "$XAMPP_ROOT/bin/mysql.server start > /dev/null &"
And add "unset DYLD_LIBRARY_PATH" on top of it. It should look like:

unset DYLD_LIBRARY_PATH
$XAMPP_ROOT/bin/mysql.server start > /dev/null &

hope can help you

How to disable the parent form when a child form is active?

While using the previously mentioned childForm.ShowDialog(this) will disable your main form, it still doesent look very disabled. However if you call Enabled = false before ShowDialog() and Enable = true after you call ShowDialog() the main form will even look like it is disabled.

var childForm = new Form();
Enabled = false;
childForm .ShowDialog(this);
Enabled = true;

How to create file execute mode permissions in Git on Windows?

There's no need to do this in two commits, you can add the file and mark it executable in a single commit:

C:\Temp\TestRepo>touch foo.sh

C:\Temp\TestRepo>git add foo.sh

C:\Temp\TestRepo>git ls-files --stage
100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0       foo.sh

As you note, after adding, the mode is 0644 (ie, not executable). However, we can mark it as executable before committing:

C:\Temp\TestRepo>git update-index --chmod=+x foo.sh

C:\Temp\TestRepo>git ls-files --stage
100755 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0       foo.sh

And now the file is mode 0755 (executable).

C:\Temp\TestRepo>git commit -m"Executable!"
[master (root-commit) 1f7a57a] Executable!
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100755 foo.sh

And now we have a single commit with a single executable file.

How to smooth a curve in the right way?

EDIT: look at this answer. Using np.cumsum is much faster than np.convolve

A quick and dirty way to smooth data I use, based on a moving average box (by convolution):

x = np.linspace(0,2*np.pi,100)
y = np.sin(x) + np.random.random(100) * 0.8

def smooth(y, box_pts):
    box = np.ones(box_pts)/box_pts
    y_smooth = np.convolve(y, box, mode='same')
    return y_smooth

plot(x, y,'o')
plot(x, smooth(y,3), 'r-', lw=2)
plot(x, smooth(y,19), 'g-', lw=2)

enter image description here

Attaching a Sass/SCSS to HTML docs

You can not "attach" a SASS/SCSS file to an HTML document.

SASS/SCSS is a CSS preprocessor that runs on the server and compiles to CSS code that your browser understands.

There are client-side alternatives to SASS that can be compiled in the browser using javascript such as LESS CSS, though I advise you compile to CSS for production use.

It's as simple as adding 2 lines of code to your HTML file.

<link rel="stylesheet/less" type="text/css" href="styles.less" />
<script src="less.js" type="text/javascript"></script>

scale fit mobile web content using viewport meta tag

I think this should help you.

<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">

Tell me if it works.

P/s: here is some media query for standard devices. http://css-tricks.com/snippets/css/media-queries-for-standard-devices/

What is the garbage collector in Java?

As objects are dynamically allocated by the new operator, you can ask how these objects are destroyed and how busy memory is freed. In other languages such as C++, you need to free manually allocated objects dynamically by the delete operator. Java has a different approach; it automatically handles deallocation. The technique is known as Garbage Collection.

It works like this: when there are no references to an object, it is assumed that this object is no longer needed and you can retrieve the memory occupied by the object. It is not necessary to explicitly destroy objects as in C++. Garbage collection occurs sporadically during program execution; It does not simply happen because there are one or more objects that are no longer used. In addition, several Java runtime implementations have different approaches to garbage collection, but most programmers do not have to worry about this when writing programs.

How do you trigger a block after a delay, like -performSelector:withObject:afterDelay:?

Swift 3 & Xcode 8.3.2

This code will help you, i add an explanation too

// Create custom class, this will make your life easier
class CustomDelay {

    static let cd = CustomDelay()

    // This is your custom delay function
    func runAfterDelay(_ delay:Double, closure:@escaping ()->()) {
        let when = DispatchTime.now() + delay
        DispatchQueue.main.asyncAfter(deadline: when, execute: closure)
    }
}


// here how to use it (Example 1)
class YourViewController: UIViewController {

    // example delay time 2 second
    let delayTime = 2.0

    override func viewDidLoad() {
        super.viewDidLoad()

        CustomDelay.cd.runAfterDelay(delayTime) {
            // This func will run after 2 second
            // Update your UI here, u don't need to worry to bring this to the main thread because your CustomDelay already make this to main thread automatically :)
            self.runFunc()
        }
    }

    // example function 1
    func runFunc() {
        // do your method 1 here
    }
}

// here how to use it (Example 2)
class YourSecondViewController: UIViewController {

    // let say you want to user run function shoot after 3 second they tap a button

    // Create a button (This is programatically, you can create with storyboard too)
    let shootButton: UIButton = {
        let button = UIButton(type: .system)
        button.frame = CGRect(x: 15, y: 15, width: 40, height: 40) // Customize where do you want to put your button inside your ui
        button.setTitle("Shoot", for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false
        return button
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        // create an action selector when user tap shoot button
        shootButton.addTarget(self, action: #selector(shoot), for: .touchUpInside)   
    }

    // example shoot function
    func shoot() {
        // example delay time 3 second then shoot
        let delayTime = 3.0

        // delay a shoot after 3 second
        CustomDelay.cd.runAfterDelay(delayTime) {
            // your shoot method here
            // Update your UI here, u don't need to worry to bring this to the main thread because your CustomDelay already make this to main thread automatically :)
        }
    }   
}

git pull error "The requested URL returned error: 503 while accessing"

here you can see the latest updated status form their website

bitbucket site status

if Git via HTTPS status is Major Outage, you will not be able to pull/push, let this status to get green

HTTP Error 503 - Service unavailable

Query an XDocument for elements by name at any depth

There are two ways to accomplish this,

  1. LINQ to XML
  2. XPath

The following are samples of using these approaches,

List<XElement> result = doc.Root.Element("emails").Elements("emailAddress").ToList();

If you use XPath, you need to do some manipulation with the IEnumerable:

IEnumerable<XElement> mails = ((IEnumerable)doc.XPathEvaluate("/emails/emailAddress")).Cast<XElement>();

Note that

var res = doc.XPathEvaluate("/emails/emailAddress");

results either a null pointer, or no results.

Write a formula in an Excel Cell using VBA

The correct character (comma or colon) depends on the purpose.

Comma (,) will sum only the two cells in question.

Colon (:) will sum all the cells within the range with corners defined by those two cells.

Getting and removing the first character of a string

substring is definitely best, but here's one strsplit alternative, since I haven't seen one yet.

> x <- 'hello stackoverflow'
> strsplit(x, '')[[1]][1]
## [1] "h"

or equivalently

> unlist(strsplit(x, ''))[1]
## [1] "h"

And you can paste the rest of the string back together.

> paste0(strsplit(x, '')[[1]][-1], collapse = '')
## [1] "ello stackoverflow"

How to call stopservice() method of Service class from the calling activity class

That looks like it should stop the service when you uncheck the checkbox. Are there any exceptions in the log? stopService returns a boolean indicating whether or not it was able to stop the service.

If you are starting your service by Intents, then you may want to extend IntentService instead of Service. That class will stop the service on its own when it has no more work to do.

AutoService

class AutoService extends IntentService {
     private static final String TAG = "AutoService";
     private Timer timer;    
     private TimerTask task;

     public onCreate() {
          timer = new Timer();
          timer = new TimerTask() {
            public void run() 
            {
                System.out.println("done");
            }
          }
     }

     protected void onHandleIntent(Intent i) {
        Log.d(TAG, "onHandleIntent");     

        int delay = 5000; // delay for 5 sec.
        int period = 5000; // repeat every sec.


        timer.scheduleAtFixedRate(timerTask, delay, period);
     }

     public boolean stopService(Intent name) {
        // TODO Auto-generated method stub
        timer.cancel();
        task.cancel();
        return super.stopService(name);
    }

}

Maven Install on Mac OS X

You can install maven using homebrew. The command is $ brew install maven

AngularJS : Initialize service with asynchronous data

Also, you can use the following techniques to provision your service globally, before actual controllers are executed: https://stackoverflow.com/a/27050497/1056679. Just resolve your data globally and then pass it to your service in run block for example.

Setting up FTP on Amazon Cloud Server

I followed clone45's answer all the way to the end. A great article! Since I needed the FTP access to install plug-ins to one of my wordpress sites, I changed the home directory to /var/www/mysitename. Then I continued to add my ftp user to the apache(or www) group like this:

sudo usermod -a -G apache myftpuser

After this I still saw this error on WP's plugin installation page: "Unable to locate WordPress Content directory (wp-content)". Searched and found this solution on a wp.org Q&A session: https://wordpress.org/support/topic/unable-to-locate-wordpress-content-directory-wp-content and added the following to the end of wp-config.php:

if(is_admin()) {
    add_filter('filesystem_method', create_function('$a', 'return "direct";' ));
    define( 'FS_CHMOD_DIR', 0751 );
}

After this my WP plugin was installed successfully.

How to validate email id in angularJs using ng-pattern

Below is the fully qualified pattern for email validation.

<input type="text" pattern="/^[_a-z0-9]+(\.[_a-z0-9]+)*@[a-z0-9-]*\.([a-z]{2,4})$/" ng-model="emailid" name="emailid"/>

<div ng-message="pattern">Please enter valid email address</div>

Calculate cosine similarity given 2 sentence strings

Well, if you are aware of word embeddings like Glove/Word2Vec/Numberbatch, your job is half done. If not let me explain how this can be tackled. Convert each sentence into word tokens, and represent each of these tokens as vectors of high dimension (using the pre-trained word embeddings, or you could train them yourself even!). So, now you just don't capture their surface similarity but rather extract the meaning of each word which comprise the sentence as a whole. After this calculate their cosine similarity and you are set.

Why does typeof array with objects return "object" and not "array"?

Quoting the spec

15.4 Array Objects

Array objects give special treatment to a certain class of property names. A property name P (in the form of a String value) is an array index if and only if ToString(ToUint32(P)) is equal to P and ToUint32(P) is not equal to 2^32-1. A property whose property name is an array index is also called an element. Every Array object has a length property whose value is always a nonnegative integer less than 2^32. The value of the length property is numerically greater than the name of every property whose name is an array index; whenever a property of an Array object is created or changed, other properties are adjusted as necessary to maintain this invariant. Specifically, whenever a property is added whose name is an array index, the length property is changed, if necessary, to be one more than the numeric value of that array index; and whenever the length property is changed, every property whose name is an array index whose value is not smaller than the new length is automatically deleted. This constraint applies only to own properties of an Array object and is unaffected by length or array index properties that may be inherited from its prototypes.

And here's a table for typeof

enter image description here


To add some background, there are two data types in JavaScript:

  1. Primitive Data types - This includes null, undefined, string, boolean, number and object.
  2. Derived data types/Special Objects - These include functions, arrays and regular expressions. And yes, these are all derived from "Object" in JavaScript.

An object in JavaScript is similar in structure to the associative array/dictionary seen in most object oriented languages - i.e., it has a set of key-value pairs.

An array can be considered to be an object with the following properties/keys:

  1. Length - This can be 0 or above (non-negative).
  2. The array indices. By this, I mean "0", "1", "2", etc are all properties of array object.

Hope this helped shed more light on why typeof Array returns an object. Cheers!

failed to resolve com.android.support:appcompat-v7:22 and com.android.support:recyclerview-v7:21.1.2

Tools > Android > SDK Manager

Select all of the packages that are not up to date and update them.

Adding three months to a date in PHP

The following should work, but you may need to change the format:

echo date('l F jS, Y (m-d-Y)', strtotime('+3 months', strtotime($DateToAdjust)));

E: Unable to locate package mongodb-org

I had the same issue in 14.04, but I fixed it by these steps:

  1. sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
  2. echo "deb http://repo.mongodb.org/apt/ubuntu "$(lsb_release -sc)"/mongodb- org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.0.list
  3. sudo apt-get update
  4. sudo apt-get install -y mongodb

It worked like charm :)

Cannot open database "test" requested by the login. The login failed. Login failed for user 'xyz\ASPNET'

This Works for me.

  1. Go to SQL Server >> Security >> Logins and right click on NT AUTHORITY\NETWORK SERVICE and select Properties
  2. In newly opened screen of Login Properties, go to the “User Mapping” tab.
  3. Then, on the “User Mapping” tab, select the desired database – especially the database for which this error message is displayed.
  4. Click OK.

Read this blog.

http://blog.sqlauthority.com/2009/08/20/sql-server-fix-error-cannot-open-database-requested-by-the-login-the-login-failed-login-failed-for-user-nt-authoritynetwork-service/

Python using enumerate inside list comprehension

Here's a way to do it:

>>> mylist = ['a', 'b', 'c', 'd']
>>> [item for item in enumerate(mylist)]
[(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd')]

Alternatively, you can do:

>>> [(i, j) for i, j in enumerate(mylist)]
[(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd')]

The reason you got an error was that you were missing the () around i and j to make it a tuple.

jquery get all form elements: input, textarea & select

The below code helps to get the details of elements from the specific form with the form id,

$('#formId input, #formId select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements from all the forms which are place in the loading page,

$('form input, form select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements which are place in the loading page even when the element is not place inside the tag,

$('input, select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

NOTE: We add the more element tag name what we need in the object list like as below,

Example: to get name of attribute "textarea",

$('input, select, textarea').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

How to check if IsNumeric

You could write an extension method:

public static class Extension
{
    public static bool IsNumeric(this string s)
    {
        float output;
        return float.TryParse(s, out output);
    }
}

What's the difference between Cache-Control: max-age=0 and no-cache?

I had this same question, and found some info in my searches (your question came up as one of the results). Here's what I determined...

There are two sides to the Cache-Control header. One side is where it can be sent by the web server (aka. "origin server"). The other side is where it can be sent by the browser (aka. "user agent").


When sent by the origin server

I believe max-age=0 simply tells caches (and user agents) the response is stale from the get-go and so they SHOULD revalidate the response (eg. with the If-Not-Modified header) before using a cached copy, whereas, no-cache tells them they MUST revalidate before using a cached copy. From 14.9.1 What is Cacheable:

no-cache

...a cache MUST NOT use the response to satisfy a subsequent request without successful revalidation with the origin server. This allows an origin server to prevent caching even by caches that have been configured to return stale responses to client requests.

In other words, caches may sometimes choose to use a stale response (although I believe they have to then add a Warning header), but no-cache says they're not allowed to use a stale response no matter what. Maybe you'd want the SHOULD-revalidate behavior when baseball stats are generated in a page, but you'd want the MUST-revalidate behavior when you've generated the response to an e-commerce purchase.

Although you're correct in your comment when you say no-cache is not supposed to prevent storage, it might actually be another difference when using no-cache. I came across a page, Cache Control Directives Demystified, that says (I can't vouch for its correctness):

In practice, IE and Firefox have started treating the no-cache directive as if it instructs the browser not to even cache the page. We started observing this behavior about a year ago. We suspect that this change was prompted by the widespread (and incorrect) use of this directive to prevent caching.

...

Notice that of late, "cache-control: no-cache" has also started behaving like the "no-store" directive.

As an aside, it appears to me that Cache-Control: max-age=0, must-revalidate should basically mean the same thing as Cache-Control: no-cache. So maybe that's a way to get the MUST-revalidate behavior of no-cache, while avoiding the apparent migration of no-cache to doing the same thing as no-store (ie. no caching whatsoever)?


When sent by the user agent

I believe shahkalpesh's answer applies to the user agent side. You can also look at 13.2.6 Disambiguating Multiple Responses.

If a user agent sends a request with Cache-Control: max-age=0 (aka. "end-to-end revalidation"), then each cache along the way will revalidate its cache entry (eg. with the If-Not-Modified header) all the way to the origin server. If the reply is then 304 (Not Modified), the cached entity can be used.

On the other hand, sending a request with Cache-Control: no-cache (aka. "end-to-end reload") doesn't revalidate and the server MUST NOT use a cached copy when responding.

How to get the width and height of an android.widget.ImageView?

Post to the UI thread works for me.

final ImageView iv = (ImageView)findViewById(R.id.scaled_image);

iv.post(new Runnable() {
            @Override
            public void run() {
                int width = iv.getMeasuredWidth();
                int height = iv.getMeasuredHeight();

            }
});

How can I delete an item from an array in VB.NET?

That depends on what you mean by delete. An array has a fixed size, so deleting doesn't really make sense.

If you want to remove element i, one option would be to move all elements j > i one position to the left (a[j - 1] = a[j] for all j, or using Array.Copy) and then resize the array using ReDim Preserve.

So, unless you are forced to use an array by some external constraint, consider using a data structure more suitable for adding and removing items. List<T>, for example, also uses an array internally but takes care of all the resizing issues itself: For removing items, it uses the algorithm mentioned above (without the ReDim), which is why List<T>.RemoveAt is an O(n) operation.

There's a whole lot of different collection classes in the System.Collections.Generic namespace, optimized for different use cases. If removing items frequently is a requirement, there are lots of better options than an array (or even List<T>).

Checking if an object is a number in C#

Yes, this works:

object x = 1;
Assert.That(x is int);

For a floating point number you would have to test using the float type:

object x = 1f;
Assert.That(x is float);

What and where are the stack and heap?

A couple of cents: I think, it will be good to draw memory graphical and more simple:

This is my vision of process memory construction with simplification for more easy understanding wht happening


Arrows - show where grow stack and heap, process stack size have limit, defined in OS, thread stack size limits by parameters in thread create API usually. Heap usually limiting by process maximum virtual memory size, for 32 bit 2-4 GB for example.

So simple way: process heap is general for process and all threads inside, using for memory allocation in common case with something like malloc().

Stack is quick memory for store in common case function return pointers and variables, processed as parameters in function call, local function variables.

Java - Convert int to Byte Array of 4 Bytes?

This should work:

public static final byte[] intToByteArray(int value) {
    return new byte[] {
            (byte)(value >>> 24),
            (byte)(value >>> 16),
            (byte)(value >>> 8),
            (byte)value};
}

Code taken from here.

Edit An even simpler solution is given in this thread.

JSON Parse File Path

var request = new XMLHttpRequest();
request.open("GET","<path_to_file>", false);
request.send(null);
var jsonData = JSON.parse(request.responseText);

This code worked for me.

Reduce git repository size

In my case, I pushed several big (> 100Mb) files and then proceeded to remove them. But they were still in the history of my repo, so I had to remove them from it as well.

What did the trick was:

bfg -b 100M  # To remove all blobs from history, whose size is superior to 100Mb
git reflog expire --expire=now --all
git gc --prune=now --aggressive

Then, you need to push force on your branch:

git push origin <your_branch_name> --force

Note: bfg is a tool that can be installed on Linux and macOS using brew:

brew install bfg

TSQL CASE with if comparison in SELECT statement

You can try with this:

WITH CTE_A As (SELECT COUNT(*) as articleNumber,A.UserID  as UserID FROM Articles A
           Inner Join Users U
           on  A.userId = U.userId 
           Group By A.userId , U.userId   ),

B as (Select us.registrationDate,

      CASE
         WHEN CTE_A.articleNumber < 2 THEN 'Ama'
         WHEN CTE_A.articleNumber < 5 THEN 'SemiAma' 
         WHEN CTE_A.articleNumber < 7 THEN 'Good'  
         WHEN CTE_A.articleNumber < 9 THEN 'Better' 
         WHEN CTE_A.articleNumber < 12 THEN 'Best'
         ELSE 'Outstanding'
         END as Ranking,
         us.hobbies, etc...
         FROM USERS Us Inner Join CTE_A 
         on CTE_A.UserID=us.UserID)

Select * from B

LISTAGG function: "result of string concatenation is too long"

SELECT RTRIM(XMLAGG(XMLELEMENT(E,colname,',').EXTRACT('//text()') ORDER BY colname).GetClobVal(),',') AS LIST
FROM tablename;

This will return a clob value, so no limit on rows.

How to sort an ArrayList in Java

Use a Comparator like this:

List<Fruit> fruits= new ArrayList<Fruit>();

Fruit fruit;
for(int i = 0; i < 100; i++)
{
  fruit = new Fruit();
  fruit.setname(...);
  fruits.add(fruit);
}

// Sorting
Collections.sort(fruits, new Comparator<Fruit>() {
        @Override
        public int compare(Fruit fruit2, Fruit fruit1)
        {

            return  fruit1.fruitName.compareTo(fruit2.fruitName);
        }
    });

Now your fruits list is sorted based on fruitName.

ReDim Preserve to a Multi-Dimensional Array in Visual Basic 6

If you not want include other function like 'ReDimPreserve' could use temporal matrix for resizing. On based to your code:

 Dim n As Integer, m As Integer, i as Long, j as Long
 Dim arrTemporal() as Variant

    n = 1
    m = 0
    Dim arrCity() As String
    ReDim arrCity(n, m)

    n = n + 1
    m = m + 1

    'VBA automatically adapts the size of the receiving matrix.
    arrTemporal = arrCity
    ReDim arrCity(n, m)

    'Loop for assign values to arrCity
    For i = 1 To UBound(arrTemporal , 1)
        For j = 1 To UBound(arrTemporal , 2)
            arrCity(i, j) = arrTemporal (i, j)
        Next
    Next

If you not declare of type VBA assume that is Variant.

Dim n as Integer, m As Integer

I have Python on my Ubuntu system, but gcc can't find Python.h

The header files are now provided by libpython2.7-dev.

You can use the search form at packages.ubuntu.com to find out what package provides Python.h.

Cant get text of a DropDownList in code - can get value but not text

What about

lstCountry.Items[lstCountry.SelectedIndex].Text;

Compare two objects with .equals() and == operator

The best way to compare 2 objects is by converting them into json strings and compare the strings, its the easiest solution when dealing with complicated nested objects, fields and/or objects that contain arrays.

sample:

import com.google.gson.Gson;


Object a = // ...;
Object b = //...;
String objectString1 = new Gson().toJson(a);
String objectString2 = new Gson().toJson(b); 

if(objectString1.equals(objectString2)){
    //do this
}

How to get a list of sub-folders and their files, ordered by folder-names

Hej man, why are you using this ?

dir /s/b/o:gn > f.txt (wrong one)

Don't you know what is that 'g' in '/o' ??

Check this out: http://www.computerhope.com/dirhlp.htm or dir /? for dir help

You should be using this instead:

dir /s/b/o:n > f.txt (right one)

PHP Pass by reference in foreach

I got here just by accident and the OP's question got my attention. Unfortunately I do not understand any of the explanations from the top. Seems to me like everybody knows it, gets it, accetps it, just cannot explain.

Luckily, a pure sentence from PHP documentation on foreach makes this completely clear:

Warning: Reference of a $value and the last array element remain even after the foreach loop. It is recommended to destroy it by unset().

How to compare timestamp dates with date-only parameter in MySQL?

You can use the DATE() function to extract the date portion of the timestamp:

SELECT * FROM table
WHERE DATE(timestamp) = '2012-05-25'

Though, if you have an index on the timestamp column, this would be faster because it could utilize an index on the timestamp column if you have one:

SELECT * FROM table
WHERE timestamp BETWEEN '2012-05-25 00:00:00' AND '2012-05-25 23:59:59'

How to use QTimer

mytimer.h:

    #ifndef MYTIMER_H
    #define MYTIMER_H

    #include <QTimer>

    class MyTimer : public QObject
    {
        Q_OBJECT
    public:
        MyTimer();
        QTimer *timer;

    public slots:
        void MyTimerSlot();
    };

    #endif // MYTIME

mytimer.cpp:

#include "mytimer.h"
#include <QDebug>

MyTimer::MyTimer()
{
    // create a timer
    timer = new QTimer(this);

    // setup signal and slot
    connect(timer, SIGNAL(timeout()),
          this, SLOT(MyTimerSlot()));

    // msec
    timer->start(1000);
}

void MyTimer::MyTimerSlot()
{
    qDebug() << "Timer...";
}

main.cpp:

#include <QCoreApplication>
#include "mytimer.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    // Create MyTimer instance
    // QTimer object will be created in the MyTimer constructor
    MyTimer timer;

    return a.exec();
}

If we run the code:

Timer...
Timer...
Timer...
Timer...
Timer...
...

resources

How to empty the content of a div

An alternative way to do it is:

var div = document.getElementById('myDiv');
while(div.firstChild)
    div.removeChild(div.firstChild);

However, using document.getElementById('myDiv').innerHTML = ""; is faster.

See: Benchmark test

N.B.

Both methods preserve the div.

Does it matter what extension is used for SQLite database files?

Pretty much down to personal choice. It may make sense to use an extension based on the database scheme you are storing; treat your database schema as a file format, with SQLite simply being an encoding used for that file format. So, you might use .bookmarks if it's storing bookmarks, or .index if it's being used as an index.

If you want to use a generic extension, I'd use .sqlite3 since that is most descriptive of what version of SQLite is needed to work with the database.

Javascript: Call a function after specific time period

You can use JavaScript Timing Events to call function after certain interval of time:

This shows the alert box after 3 seconds:

setInterval(function(){alert("Hello")},3000);

You can use two method of time event in javascript.i.e.

  1. setInterval(): executes a function, over and over again, at specified time intervals
  2. setTimeout() : executes a function, once, after waiting a specified number of milliseconds

git visual diff between branches

Use git diff with a range.

git diff branch1..branch2

This will compare the tips of each branch.

If you really want some GUI software, you can try something like SourceTree which supports Mac OS X and Windows.

Jackson - How to process (deserialize) nested JSON?

@Patrick I would improve your solution a bit

@Override
public Object deserialize(JsonParser jp, DeserializationContext ctxt)
        throws IOException, JsonProcessingException {        
    ObjectNode objectNode = jp.readValueAsTree();
    JsonNode wrapped = objectNode.get(wrapperKey);
    JsonParser parser = node.traverse();
    parser.setCodec(jp.getCodec());
    Vendor mapped = parser.readValueAs(Vendor.class);
    return mapped;
}

It works faster :)

Eclipse won't compile/run java file

right click somewhere on the file or in project explorer and choose 'run as'->'java application'

Vector of Vectors to create matrix

I'm not familiar with c++, but a quick look at the documentation suggests that this should work:

//cin>>CC; cin>>RR; already done
vector<vector<int> > matrix;
for(int i = 0; i<RR; i++)
{
    vector<int> myvector;
    for(int j = 0; j<CC; j++)
    {
        int tempVal = 0;
        cout<<"Enter the number for Matrix 1";
        cin>>tempVal;
        myvector.push_back(tempVal);
    }
    matrix.push_back(myvector);
}

Gitignore not working

The files/folder in your version control will not just delete themselves just because you added them to the .gitignore. They are already in the repository and you have to remove them. You can just do that with this:

Remember to commit everything you've changed before you do this!

git rm -rf --cached .
git add .

This removes all files from the repository and adds them back (this time respecting the rules in your .gitignore).

How to format a float in javascript?

var x = 0.3445434
x = Math.round (x*100) / 100 // this will make nice rounding