#Browse information | Programs & Examples on Browse information

How do I get formatted JSON in .NET using C#?

Using System.Text.Json set JsonSerializerOptions.WriteIndented = true:

JsonSerializerOptions options = new JsonSerializerOptions { WriteIndented = true };
string json = JsonSerializer.Serialize<Type>(object, options);

How to escape a single quote inside awk

This maybe what you're looking for:

awk 'BEGIN {FS=" ";} {printf "'\''%s'\'' ", $1}'

That is, with '\'' you close the opening ', then print a literal ' by escaping it and finally open the ' again.

Min width in window resizing

Well, you pretty much gave yourself the answer. In your CSS give the containing element a min-width. If you have to support IE6 you can use the min-width-trick:

#container {
    min-width:800px;
    width: auto !important;
    width:800px;
}

That will effectively give you 800px min-width in IE6 and any up-to-date browsers.

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

The .pid is the processid of the running mysql server instance. It appears in the data folder when mysql is running and removes itself when mysql is shutdown.

If the OSX operating system is upgraded and mysql is not shutdown properly before the upgrade,mysql quits when it started up it just quits because of the .pid file.

There are a few tricks you can try, http://coolestguidesontheplanet.com/mysql-error-server-quit-without-updating-pid-file/ failing these a reinstall is needed.

Print values for multiple variables on the same line from within a for-loop

As an additional note, there is no need for the for loop because of R's vectorization.

This:

P <- 243.51
t <- 31 / 365
n <- 365

for (r in seq(0.15, 0.22, by = 0.01))    
     A <- P * ((1 + (r/ n))^ (n * t))
     interest <- A - P
}

is equivalent to:

P <- 243.51
t <- 31 / 365
n <- 365
r <- seq(0.15, 0.22, by = 0.01)
A <- P * ((1 + (r/ n))^ (n * t))
interest <- A - P

Because r is a vector, the expression above containing it is performed for all values of the vector.

Undo working copy modifications of one file in Git?

git checkout <commit> <filename>

I used this today because I realized that my favicon had been overwritten a few commits ago when I upgrated to drupal 6.10, so I had to get it back. Here is what I did:

git checkout 088ecd favicon.ico

How do I print the type or class of a variable in Swift?

In the latest XCode 6.3 with Swift 1.2, this is the only way I found:

if view.classForCoder.description() == "UISegment" {
    ...
}

How do I solve this "Cannot read property 'appendChild' of null" error?

For all those facing a similar issue, I came across this same issue when i was trying to run a particular code snippet, shown below.

<html>
    <head>
        <script>
                var div, container = document.getElementById("container")
                for(var i=0;i<5;i++){
                    div = document.createElement("div");
                    div.onclick = function() { 
                        alert("This is a box #"+i);
                    };
                    container.appendChild(div);
                }
            </script>

    </head>
    <body>
        <div id="container"></div>
    </body>
 </html>

https://codepen.io/pcwanderer/pen/MMEREr

Looking at the error in the console for the above code.

Since the document.getElementById is returning a null and as null does not have a attribute named appendChild, therefore a error is thrown. To solve the issue see the code below.

<html>
    <head>
        <style>
        #container{
            height: 200px;
            width: 700px;
            background-color: red;
            margin: 10px;
        }


        div{
            height: 100px;
            width: 100px;
            background-color: purple;
            margin: 20px;
            display: inline-block;
        }
        </style>
    </head>
    <body>
        <div id="container"></div>
        <script>
                var div, container = document.getElementById("container")
                for(let i=0;i<5;i++){
                    div = document.createElement("div");
                    div.onclick = function() { 
                        alert("This is a box #"+i);
                    };
                    container.appendChild(div);
                }
            </script>
    </body>
</html>

https://codepen.io/pcwanderer/pen/pXWBQL

I hope this helps. :)

Check cell for a specific letter or set of letters

Some options without REGEXMATCH, since you might want to be case insensitive and not want say blast or ablative to trigger a YES. Using comma as the delimiter, as in the OP, and for the moment ignoring the IF condition:

First very similar to @user1598086's answer:

=FIND("bla",A1)

Is case sensitive but returns #VALUE! rather than NO and a number rather than YES (both of which can however be changed to NO/YES respectively).

=SEARCH("bla",A1)

Case insensitive, so treats Black and black equally. Returns as above.

The former (for the latter equivalent) to indicate whether bla present after the first three characters in A1:

=FIND("bla",A1,4)

Returns a number for blazer, black but #VALUE! for blazer, blue.

To find Bla only when a complete word on its own (ie between spaces - not at the start or end of a 'sentence'):

=SEARCH(" Bla ",A1)

Since the return in all cases above is either a number ("found", so YES preferred) or #VALUE! we can use ISERROR to test for #VALUE! within an IF formula, for instance taking the first example above:

 =if(iserror(FIND("bla",A1)),"NO","YES")

Longer than the regexmatch but the components are easily adjustable.

How do I initialize a byte array in Java?

My preferred option in this circumstance is to use org.apache.commons.codec.binary.Hex which has useful APIs for converting between Stringy hex and binary. For example:

Hex.decodeHex(char[] data) which throws a DecoderException if there are non-hex characters in the array, or if there are an odd number of characters.
Hex.encodeHex(byte[] data) is the counterpart to the decode method above, and spits out the char[].
Hex.encodeHexString(byte[] data) which converts back from a byte array to a String.

Usage: Hex.decodeHex("dd645a2564cbe648c8336d2be5eafaa6".toCharArray())

Passing JavaScript array to PHP through jQuery $.ajax

This is because PHP reads your value as a string. If I don't want to pass my data as an object (like in the previous answers, which are also fine), I just do this in my PHP:

 $activitiesString = $_POST['activitiesArray'];
 $activitiesArray = (explode(",",$activitiesString));

The last line splits string into bits after every comma. Now $activitiesArray is also an array. It works even if there is no comma (only one element in your javascript array).

Happy coding!

Use multiple custom fonts using @font-face?

Check out fontsquirrel. They have a web font generator, which will also spit out a suitable stylesheet for your font (look for "@font-face kit"). This stylesheet can be included in your own, or you can use it as a template.

Fetch the row which has the Max value for a column

i thing you shuold make this variant to previous query:

SELECT UserId, Value FROM Users U1 WHERE 
Date = ( SELECT MAX(Date)    FROM Users where UserId = U1.UserId)

Using jQuery to compare two arrays of Javascript objects

Try this

function check(c,d){
  var a = c, b = d,flg = 0;
  if(a.length == b.length) 
  { 
     for(var i=0;i<a.length;i++) 
           a[i] != b[i] ? flg++ : 0; 
  } 
  else  
  { 
     flg = 1; 
  } 
  return flg = 0;
}

Execute raw SQL using Doctrine 2

I found out the answer is probably:

A NativeQuery lets you execute native SQL, mapping the results according to your specifications. Such a specification that describes how an SQL result set is mapped to a Doctrine result is represented by a ResultSetMapping.

Source: Native SQL.

What is the difference between Hibernate and Spring Data JPA

If you prefer simplicity and more control on SQL queries then I would suggest going with Spring Data/ Spring JDBC.

Its good amount of learning curve in JPA and sometimes difficult to debug issues. On the other hand, while you have full control over SQL, it becomes much easier to optimize query and improve performance. You can easily share your SQL with DBA or someone who has a better understanding of Database.

Convert python datetime to timestamp in milliseconds

In Python 3 this can be done in 2 steps:

Convert timestring to datetime object
Multiply the timestamp of the datetime object by 1000 to convert it to milliseconds.

For example like this:

from datetime import datetime

dt_obj = datetime.strptime('20.12.2016 09:38:42,76',
                           '%d.%m.%Y %H:%M:%S,%f')
millisec = dt_obj.timestamp() * 1000

print(millisec)

Output:

1482223122760.0

strptime accepts your timestring and a format string as input. The timestring (first argument) specifies what you actually want to convert to a datetime object. The format string (second argument) specifies the actual format of the string that you have passed.

Here is the explanation of the format specifiers from the official documentation:

%d - Day of the month as a zero-padded decimal number.
%m - Month as a zero-padded decimal number.
%Y - Year with century as a decimal number
%H - Hour (24-hour clock) as a zero-padded decimal number.
%M - Minute as a zero-padded decimal number.
%S - Second as a zero-padded decimal number.
%f - Microsecond as a decimal number, zero-padded on the left.

What is the difference between encrypting and signing in asymmetric encryption?

When encrypting, you use their public key to write a message and they use their private key to read it.

When signing, you use your private key to write message's signature, and they use your public key to check if it's really yours.

I want to use my private key to generate messages so only I can possibly be the sender.

I want my public key to be used to read the messages and I do not care who reads them

This is signing, it is done with your private key.

I want to be able to encrypt certain information and use it as a product key for my software.

I only care that I am the only one who can generate these.

If you only need to know it to yourself, you don't need to mess with keys to do this. You may just generate random data and keep it in a database.

But if you want people to know that the keys are really yours, you need to generate random data, keep in it a database AND sign it with your key.

I would like to include my public key in my software to decrypt/read the signature of the key.

You'll probably need to purchase a certificate for your public key from a commercial provider like Verisign or Thawte, so that people may check that no one had forged your software and replaced your public key with theirs.

How to use BeanUtils.copyProperties?

There are two BeanUtils.copyProperties(parameter1, parameter2) in Java.

One is

org.apache.commons.beanutils.BeanUtils.copyProperties(Object dest, Object orig)

Another is

org.springframework.beans.BeanUtils.copyProperties(Object source, Object target)

Pay attention to the opposite position of parameters.

Django template how to look up a dictionary value with a variable

Write a custom template filter:

from django.template.defaulttags import register
...
@register.filter
def get_item(dictionary, key):
    return dictionary.get(key)

(I use .get so that if the key is absent, it returns none. If you do dictionary[key] it will raise a KeyError then.)

usage:

{{ mydict|get_item:item.NAME }}

Java : Cannot format given Object as a Date

java.time

I should like to contribute the modern answer. The SimpleDateFormat class is notoriously troublesome, and while it was reasonable to fight one’s way through with it when this question was asked six and a half years ago, today we have much better in java.time, the modern Java date and time API. SimpleDateFormat and its friend Date are now considered long outdated, so don’t use them anymore.

    DateTimeFormatter monthFormatter = DateTimeFormatter.ofPattern("MM/uuuu");
    String dateformat = "2012-11-17T00:00:00.000-05:00";
    OffsetDateTime dateTime = OffsetDateTime.parse(dateformat);
    String monthYear = dateTime.format(monthFormatter);
    System.out.println(monthYear);

Output:

11/2012

I am exploiting the fact that your string is in ISO 8601 format, the international standard, and that the classes of java.time parse this format as their default, that is, without any explicit formatter. It’s stil true what the other answers say, you need to parse the original string first, then format the resulting date-time object into a new string. Usually this requires two formatters, only in this case we’re lucky and can do with just one formatter.

What went wrong in your code

As others have said, SimpleDateFormat.format cannot accept a String argument, also when the parameter type is declared to be Object.
Because of the exception you didn’t get around to discovering: there is also a bug in your format pattern string, mm/yyyy. Lowercase mm os for minute of the hour. You need uppercase MM for month.
Finally the Java naming conventions say to use a lowercase first letter in variable names, so use lowercase m in monthYear (also because java.time includes a MonthYear class with uppercase M, so to avoid confusion).

Bootstrap Carousel Full Screen

Simply Add 'carousel-item' class in place of item class.

Implementing a HashMap in C

The primary goal of a hashmap is to store a data set and provide near constant time lookups on it using a unique key. There are two common styles of hashmap implementation:

Separate chaining: one with an array of buckets (linked lists)
Open addressing: a single array allocated with extra space so index collisions may be resolved by placing the entry in an adjacent slot.

Separate chaining is preferable if the hashmap may have a poor hash function, it is not desirable to pre-allocate storage for potentially unused slots, or entries may have variable size. This type of hashmap may continue to function relatively efficiently even when the load factor exceeds 1.0. Obviously, there is extra memory required in each entry to store linked list pointers.

Hashmaps using open addressing have potential performance advantages when the load factor is kept below a certain threshold (generally about 0.7) and a reasonably good hash function is used. This is because they avoid potential cache misses and many small memory allocations associated with a linked list, and perform all operations in a contiguous, pre-allocated array. Iteration through all elements is also cheaper. The catch is hashmaps using open addressing must be reallocated to a larger size and rehashed to maintain an ideal load factor, or they face a significant performance penalty. It is impossible for their load factor to exceed 1.0.

Some key performance metrics to evaluate when creating a hashmap would include:

Maximum load factor
Average collision count on insertion
Distribution of collisions: uneven distribution (clustering) could indicate a poor hash function.
Relative time for various operations: put, get, remove of existing and non-existing entries.

Here is a flexible hashmap implementation I made. I used open addressing and linear probing for collision resolution.

https://github.com/DavidLeeds/hashmap

java.lang.ClassNotFoundException on working app

In my case I had to add android:name=".activity.SkeletonAppActivity" instead of android:name=".SkeletonAppActivity" in the manifest file for the main activity. SkeletonAppActivity was in a different package from the application class. Good luck!

Find all elements on a page whose element ID contains a certain text using jQuery

This selects all DIVs with an ID containing 'foo' and that are visible

$("div:visible[id*='foo']");

Call a Vue.js component method from outside the component

Sometimes you want to keep these things contained within your component. Depending on DOM state (the elements you're listening on must exist in DOM when your Vue component is instantiated), you can listen to events on elements outside of your component from within your Vue component. Let's say there is an element outside of your component, and when the user clicks it, you want your component to respond.

In html you have:

<a href="#" id="outsideLink">Launch the component</a>
...
<my-component></my-component>

In your Vue component:

    methods() {
      doSomething() {
        // do something
      }
    },
    created() {
       document.getElementById('outsideLink').addEventListener('click', evt => 
       {
          this.doSomething();
       });
    }

How to set null value to int in c#?

You cannot set an int to null. Use a nullable int (int?) instead:

int? value = null;

Unable to create a constant value of type Only primitive types or enumeration types are supported in this context

In my case, I was able to resolve the issue by doing the following:

I changed my code from this:

var r2 = db.Instances.Where(x => x.Player1 == inputViewModel.InstanceList.FirstOrDefault().Player2 && x.Player2 == inputViewModel.InstanceList.FirstOrDefault().Player1).ToList();

To this:

var p1 = inputViewModel.InstanceList.FirstOrDefault().Player1;
var p2 = inputViewModel.InstanceList.FirstOrDefault().Player2;
var r1 = db.Instances.Where(x => x.Player1 == p1 && x.Player2 == p2).ToList();

How to get row from R data.frame

Logical indexing is very R-ish. Try:

 x[ x$A ==5 & x$B==4.25 & x$C==4.5 , ]

Or:

subset( x, A ==5 & B==4.25 & C==4.5 )

SVG drop shadow using css3

Use the ~~new~~ CSS filter property.

Supported by webkit browsers, Firefox 34+ and Edge.

You can use this polyfill that will support FF < 34, IE6+.

You would use it like so:

_x000D_

/* Use -webkit- only if supporting: Chrome < 54, iOS < 9.3, Android < 4.4.4 */_x000D_
_x000D_
.shadow {_x000D_
  -webkit-filter: drop-shadow( 3px 3px 2px rgba(0, 0, 0, .7));_x000D_
  filter: drop-shadow( 3px 3px 2px rgba(0, 0, 0, .7));_x000D_
  /* Similar syntax to box-shadow */_x000D_
}

_x000D_

<img src="https://upload.wikimedia.org/wikipedia/commons/c/ce/Star_wars2.svg" alt="" class="shadow" width="200">_x000D_
_x000D_
<!-- Or -->_x000D_
_x000D_
<svg class="shadow" ...>_x000D_
    <rect x="10" y="10" width="200" height="100" fill="#bada55" />_x000D_
</svg>

_x000D_

This approach differs from the box-shadow effect in that it accounts for opacity and does not apply the drop shadow effect to the box but rather to the corners of the svg element itself.

Please Note: This approach only works when the class is placed on the <svg> element alone. You can NOT use this on an inline svg element such as <rect>.

<!-- This will NOT work! -->
<svg><rect class="shadow" ... /></svg>

Read more about css filters on html5rocks.

MySQL: Can't create table (errno: 150)

In some cases, you may encounter this error message if there are different engines between the relating tables. For example, a table may be using InnoDB while the other uses MyISAM. Both need to be same

How to set environment variable for everyone under my linux system?

If your LinuxOS has this file:

/etc/environment

You can use it to permanently set environmental variables for all users.

Extracted from: http://www.sysadmit.com/2016/04/linux-variables-de-entorno-permanentes.html

Pass request headers in a jQuery AJAX GET call

Use beforeSend:

$.ajax({
         url: "http://localhost/PlatformPortal/Buyers/Account/SignIn",
         data: { signature: authHeader },
         type: "GET",
         beforeSend: function(xhr){xhr.setRequestHeader('X-Test-Header', 'test-value');},
         success: function() { alert('Success!' + authHeader); }
      });

http://api.jquery.com/jQuery.ajax/

http://www.w3.org/TR/XMLHttpRequest/#the-setrequestheader-method

Check if PHP-page is accessed from an iOS device

Use the user agent from $_SERVER['HTTP_USER_AGENT'], and for simple detection you can use this script:

<?php

//Detect special conditions devices
$iPod    = stripos($_SERVER['HTTP_USER_AGENT'],"iPod");
$iPhone  = stripos($_SERVER['HTTP_USER_AGENT'],"iPhone");
$iPad    = stripos($_SERVER['HTTP_USER_AGENT'],"iPad");
$Android = stripos($_SERVER['HTTP_USER_AGENT'],"Android");
$webOS   = stripos($_SERVER['HTTP_USER_AGENT'],"webOS");

//do something with this information
if( $iPod || $iPhone ){
    //browser reported as an iPhone/iPod touch -- do something here
}else if($iPad){
    //browser reported as an iPad -- do something here
}else if($Android){
    //browser reported as an Android device -- do something here
}else if($webOS){
    //browser reported as a webOS device -- do something here
}

?>

If you want to know more details of the user device I recommended to use one of the following solutions: http://51degrees.mobi or http://deviceatlas.com

Multiple distinct pages in one HTML file

I used the following trick for the same problem. The good thing is it doesn't require any javascript.

CSS:

.body {
     margin: 0em;
}

.page {
    width: 100vw;
    height: 100vh;
    position: fixed;
    top: 0;
    left: -100vw;
    overflow-y: auto;
    z-index: 0;
    background-color: hsl(0,0%,100%);
}

  .page:target {
    left: 0vw;
    z-index: 1;
}

HTML:

<ul>
    <li>Click <a href="#one">here</a> for page 1</li>
    <li>Click <a href="#two">here</a> for page 2</li>
</ul>

<div class="page" id="one">
    Content of page 1 goes here.

    <ul>
        <li><a href="#">Back</a></li>
        <li><a href="#two">Page 2</a></li>
    </ul>
</div>

<div class="page" id="two">
    Content of page 2 goes here.

    <ul style="margin-bottom: 100vh;">
        <li><a href="#">Back</a></li>
        <li><a href="#one">Page 1</a></li>
    </ul>
</div>

See a JSFiddle.

Added advantage: as your url changes along, you can use it to link to specific pages. This is something the method won't let you do.

Hope this helps!

What's the fastest algorithm for sorting a linked list?

This is a nice little paper on this topic. His empirical conclusion is that Treesort is best, followed by Quicksort and Mergesort. Sediment sort, bubble sort, selection sort perform very badly.

A COMPARATIVE STUDY OF LINKED LIST SORTING ALGORITHMS by Ching-Kuang Shene

http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.31.9981

How to force remounting on React components?

What's probably happening is that React thinks that only one MyInput (unemployment-duration) is added between the renders. As such, the job-title never gets replaced with the unemployment-reason, which is also why the predefined values are swapped.

When React does the diff, it will determine which components are new and which are old based on their key property. If no such key is provided in the code, it will generate its own.

The reason why the last code snippet you provide works is because React essentially needs to change the hierarchy of all elements under the parent div and I believe that would trigger a re-render of all children (which is why it works). Had you added the span to the bottom instead of the top, the hierarchy of the preceding elements wouldn't change, and those element's wouldn't re-render (and the problem would persist).

Here's what the official React documentation says:

The situation gets more complicated when the children are shuffled around (as in search results) or if new components are added onto the front of the list (as in streams). In these cases where the identity and state of each child must be maintained across render passes, you can uniquely identify each child by assigning it a key.

When React reconciles the keyed children, it will ensure that any child with key will be reordered (instead of clobbered) or destroyed (instead of reused).

You should be able to fix this by providing a unique key element yourself to either the parent div or to all MyInput elements.

For example:

render(){
    if (this.state.employed) {
        return (
            <div key="employed">
                <MyInput ref="job-title" name="job-title" />
            </div>
        );
    } else {
        return (
            <div key="notEmployed">
                <MyInput ref="unemployment-reason" name="unemployment-reason" />
                <MyInput ref="unemployment-duration" name="unemployment-duration" />
            </div>
        );
    }
}

render(){
    if (this.state.employed) {
        return (
            <div>
                <MyInput key="title" ref="job-title" name="job-title" />
            </div>
        );
    } else {
        return (
            <div>
                <MyInput key="reason" ref="unemployment-reason" name="unemployment-reason" />
                <MyInput key="duration" ref="unemployment-duration" name="unemployment-duration" />
            </div>
        );
    }
}

Now, when React does the diff, it will see that the divs are different and will re-render it including all of its' children (1st example). In the 2nd example, the diff will be a success on job-title and unemployment-reason since they now have different keys.

You can of course use any keys you want, as long as they are unique.

Update August 2017

For a better insight into how keys work in React, I strongly recommend reading my answer to Understanding unique keys in React.js.

Update November 2017

This update should've been posted a while ago, but using string literals in ref is now deprecated. For example ref="job-title" should now instead be ref={(el) => this.jobTitleRef = el} (for example). See my answer to Deprecation warning using this.refs for more info.

Declare Variable for a Query String

I will point out that in the article linked in the top rated answer The Curse and Blessings of Dynamic SQL the author states that the answer is not to use dynamic SQL. Scroll almost to the end to see this.

From the article: "The correct method is to unpack the list into a table with a user-defined function or a stored procedure."

Of course, once the list is in a table you can use a join. I could not comment directly on the top rated answer, so I just added this comment.

Highlight the difference between two strings in PHP

I had terrible trouble with the both the PEAR-based and the simpler alternatives shown. So here's a solution that leverages the Unix diff command (obviously, you have to be on a Unix system or have a working Windows diff command for it to work). Choose your favourite temporary directory, and change the exceptions to return codes if you prefer.

/**
 * @brief Find the difference between two strings, lines assumed to be separated by "\n|
 * @param $new string The new string
 * @param $old string The old string
 * @return string Human-readable output as produced by the Unix diff command,
 * or "No changes" if the strings are the same.
 * @throws Exception
 */
public static function diff($new, $old) {
  $tempdir = '/var/somewhere/tmp'; // Your favourite temporary directory
  $oldfile = tempnam($tempdir,'OLD');
  $newfile = tempnam($tempdir,'NEW');
  if (!@file_put_contents($oldfile,$old)) {
    throw new Exception('diff failed to write temporary file: ' . 
         print_r(error_get_last(),true));
  }
  if (!@file_put_contents($newfile,$new)) {
    throw new Exception('diff failed to write temporary file: ' . 
         print_r(error_get_last(),true));
  }
  $answer = array();
  $cmd = "diff $newfile $oldfile";
  exec($cmd, $answer, $retcode);
  unlink($newfile);
  unlink($oldfile);
  if ($retcode != 1) {
    throw new Exception('diff failed with return code ' . $retcode);
  }
  if (empty($answer)) {
    return 'No changes';
  } else {
    return implode("\n", $answer);
  }
}

Warning about `$HTTP_RAW_POST_DATA` being deprecated

It turns out that my understanding of the error message was wrong. I'd say it features very poor choice of words. Googling around shown me someone else misunderstood the message exactly like I did - see PHP bug #66763.

After totally unhelpful "This is the way the RMs wanted it to be." response to that bug by Mike, Tyrael explains that setting it to "-1" doesn't make just the warning to go away. It does the right thing, i.e. it completely disables populating the culprit variable. Turns out that having it set to 0 STILL populates data under some circumstances. Talk about bad design! To cite PHP RFC:

Change always_populate_raw_post_data INI setting to accept three values instead of two.

-1: The behavior of master; don't ever populate $GLOBALS[HTTP_RAW_POST_DATA]

0/off/whatever: BC behavior (populate if content-type is not registered or request method is other than POST)

1/on/yes/true: BC behavior (always populate $GLOBALS[HTTP_RAW_POST_DATA])

So yeah, setting it to -1 not only avoids the warning, like the message said, but it also finally disables populating this variable, which is what I wanted.

CodeIgniter -> Get current URL relative to base url

// For current url
echo base_url(uri_string());

How to view query error in PDO PHP

I'm guessing that your complaint is that the exception is not firing. PDO is most likely configured to not throw exceptions. Enable them with this:

$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

How do I split a string with multiple separators in JavaScript?

Not the best way but works to Split with Multiple and Different seperators/delimiters

html

<button onclick="myFunction()">Split with Multiple and Different seperators/delimiters</button>
<p id="demo"></p>

javascript

<script>
function myFunction() {

var str = "How : are | you doing : today?";
var res = str.split(' | ');

var str2 = '';
var i;
for (i = 0; i < res.length; i++) { 
    str2 += res[i];

    if (i != res.length-1) {
      str2 += ",";
    }
}
var res2 = str2.split(' : ');

//you can add countless options (with or without space)

document.getElementById("demo").innerHTML = res2;
</script>

The entity cannot be constructed in a LINQ to Entities query

you can add AsEnumerable to your collection like the follow :

public IQueryable<Product> GetProducts(int categoryID)
{
    return from p in db.Products.AsEnumerable()
           where p.CategoryID== categoryID
           select new Product { Name = p.Name};
}

Junit - run set up method once

Use Spring's @PostConstruct method to do all initialization work and this method runs before any of the @Test is executed

SQL grouping by all the columns

You can use Group by All but be careful as Group by All will be removed from future versions of SQL server.

IDENTITY_INSERT is set to OFF - How to turn it ON?

Shouldn't you be setting identity_Insert ON, inserting the records and then turning it back off?

Like this:

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
SET IDENTITY_INSERT tbl_content ON
GO

ALTER procedure [dbo].[spInsertDeletedIntoTBLContent]
@ContentID int, 
SET IDENTITY_INSERT tbl_content ON
...insert command...
SET IDENTITY_INSERT tbl_content OFF

Javascript one line If...else...else if statement

You can chain as much conditions as you want. If you do:

var x = (false)?("1true"):((true)?"2true":"2false");

You will get x="2true"

So it could be expressed as:

var variable = (condition) ? (true block) : ((condition)?(true block):(false block))

How can I reuse a navigation bar on multiple pages?

You can use php for making multi-page website.

Create a header.php in which you should put all your html code for menu's and social media etc
Insert header.php in your index.php using following code

<? php include 'header.php'; ?>

(Above code will dump all html code before this)Your site body content.

Similarly you can create footer and other elements with ease. PHP built-in support html code in their extensions. So, better learn this easy fix.

How do I extract data from a DataTable?

The DataTable has a collection .Rows of DataRow elements.

Each DataRow corresponds to one row in your database, and contains a collection of columns.

In order to access a single value, do something like this:

 foreach(DataRow row in YourDataTable.Rows)
 { 
     string name = row["name"].ToString();
     string description = row["description"].ToString();
     string icoFileName = row["iconFile"].ToString();
     string installScript = row["installScript"].ToString();
 }

How to use css style in php

Just put the CSS outside the PHP Tag. Here:

<html>
<head>
    <title>Title</title>
    <style type="text/css">
    table {
        margin: 8px;
    }
    </style>
</head>
<body>
    <table>
    <tr><th>ID</th><th>hashtag</th></tr>
    <?php
    while($row = mysql_fetch_row($result))
    {
        echo "<tr onmouseover=\"hilite(this)\" onmouseout=\"lowlite(this)\"><td>$row[0]</td>                <td>$row[1]</td></tr>\n";
    }
    ?>
    </table>
</body>
</html>

Take note that the PHP tags are <?php and ?>.

How to get evaluated attributes inside a custom directive

The other answers here are very much correct, and valuable. But sometimes you just want simple: to get a plain old parsed value at directive instantiation, without needing updates, and without messing with isolate scope. For instance, it can be handy to provide a declarative payload into your directive as an array or hash-object in the form:

my-directive-name="['string1', 'string2']"

In that case, you can cut to the chase and just use a nice basic angular.$eval(attr.attrName).

element.val("value = "+angular.$eval(attr.value));

Working Fiddle.

What is the difference between dynamic and static polymorphism in Java?

Method Overloading is known as Static Polymorphism and also Known as Compile Time Polymorphism or Static Binding because overloaded method calls get resolved at compile time by the compiler on the basis of the argument list and the reference on which we are calling the method.

And Method Overriding is known as Dynamic Polymorphism or simple Polymorphism or Runtime Method Dispatch or Dynamic Binding because overridden method call get resolved at runtime.

In order to understand why this is so let's take an example of Mammal and Human class

class Mammal {
    public void speak() { System.out.println("ohlllalalalalalaoaoaoa"); }
}

class Human extends Mammal {

    @Override
    public void speak() { System.out.println("Hello"); }

    public void speak(String language) {
        if (language.equals("Hindi")) System.out.println("Namaste");
        else System.out.println("Hello");
    }

}

I have included output as well as bytecode of in below lines of code

Mammal anyMammal = new Mammal();
anyMammal.speak();  // Output - ohlllalalalalalaoaoaoa
// 10: invokevirtual #4 // Method org/programming/mitra/exercises/OverridingInternalExample$Mammal.speak:()V

Mammal humanMammal = new Human();
humanMammal.speak(); // Output - Hello
// 23: invokevirtual #4 // Method org/programming/mitra/exercises/OverridingInternalExample$Mammal.speak:()V

Human human = new Human();
human.speak(); // Output - Hello
// 36: invokevirtual #7 // Method org/programming/mitra/exercises/OverridingInternalExample$Human.speak:()V

human.speak("Hindi"); // Output - Namaste
// 42: invokevirtual #9 // Method org/programming/mitra/exercises/OverridingInternalExample$Human.speak:(Ljava/lang/String;)V

And by looking at above code we can see that the bytecodes of humanMammal.speak() , human.speak() and human.speak("Hindi") are totally different because the compiler is able to differentiate between them based on the argument list and class reference. And this is why Method Overloading is known as Static Polymorphism.

But bytecode for anyMammal.speak() and humanMammal.speak() is same because according to compiler both methods are called on Mammal reference but the output for both method calls is different because at runtime JVM knows what object a reference is holding and JVM calls the method on the object and this is why Method Overriding is known as Dynamic Polymorphism.

So from above code and bytecode, it is clear that during compilation phase calling method is considered from the reference type. But at execution time method will be called from the object which the reference is holding.

If you want to know more about this you can read more on How Does JVM Handle Method Overloading and Overriding Internally.

how to dynamically add options to an existing select in vanilla javascript

The simplest way is:

selectElement.add(new Option('Text', 'value'));

Yes, that simple. And it works even in IE8. And has other optional parameters.

See docs:

Python convert decimal to hex

If without '0x' prefix:

'{0:x}'.format(int(dec))

else use built-in hex() funtion.

How to use protractor to check if an element is visible?

If there are multiple elements in DOM with same class name. But only one of element is visible.

element.all(by.css('.text-input-input')).filter(function(ele){
        return ele.isDisplayed();
    }).then(function(filteredElement){
        filteredElement[0].click();
    });

In this example filter takes a collection of elements and returns a single visible element using isDisplayed().

ASP.NET MVC 3 - redirect to another action

You have to write this code instead of return View(); :

return RedirectToAction("ActionName", "ControllerName");

java.lang.OutOfMemoryError: Java heap space

To avoid that exception, if you are using JUnit and Spring try adding this in every test class:

@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_CLASS)

#pragma once vs include guards?

#pragma once allows the compiler to skip the file completely when it occurs again - instead of parsing the file until it reaches the #include guards.

As such, the semantics are a little different, but they are identical if they are used they way they are intended to be used.

Combining both is probably the safest route to go, as in the worst case (a compiler flagging unknown pragmas as actual errors, not just warnings) you would just to have to remove the #pragma's themselves.

When you limit your platforms to, say "mainstream compilers on the desktop", you could safely omit the #include guards, but I feel uneasy on that, too.

OT: if you have other tips/experiences to share on speeding up builds, I'd be curious.

Javascript objects: get parent

This is an old question but as I came across it looking for an answer I thought I will add my answer to this to help others as soon as they got the same problem.

I have a structure like this:

var structure = {
    "root":{
        "name":"Main Level",
        nodes:{
            "node1":{
                "name":"Node 1"  
            },
            "node2":{
                "name":"Node 2"  
            },
            "node3":{
                "name":"Node 3"  
            }
        }
    }
}

Currently, by referencing one of the sub nodes I don't know how to get the parent node with it's name value "Main Level".

Now I introduce a recursive function that travels the structure and adds a parent attribute to each node object and fills it with its parent like so.

var setParent = function(o){
     if(o.nodes != undefined){
          for(n in o.nodes){
              o.nodes[n].parent = o;
              setParent(o.nodes[n]);
          }
     }
}

Then I just call that function and can now get the parent of the current node in this object tree.

setParent(structure.root);

If I now have a reference to the seconds sub node of root, I can just call.

var node2 = structure.root.nodes["node2"];
console.log(node2.parent.name);

and it will output "Main Level".

Hope this helps..

How to hide/show div tags using JavaScript?

Use the following code:

function hide {
document.getElementById('div').style.display = "none";
}
function show {
document.getElementById('div').style.display = "block";
}

Using GroupBy, Count and Sum in LINQ Lambda Expressions

        var q = from b in listOfBoxes
                group b by b.Owner into g
                select new
                           {
                               Owner = g.Key,
                               Boxes = g.Count(),
                               TotalWeight = g.Sum(item => item.Weight),
                               TotalVolume = g.Sum(item => item.Volume)
                           };

Python SQLite: database is locked

Oh, your traceback gave it away: you have a version conflict. You have installed some old version of sqlite in your local dist-packages directory when you already have sqlite3 included in your python2.6 distribution and don't need and probably can't use the old sqlite version. First try:

$ python -c "import sqlite3"

and if that doesn't give you an error, uninstall your dist-package:

easy_install -mxN sqlite

and then import sqlite3 in your code instead and have fun.

How do I get the last four characters from a string in C#?

string mystring = "34234234d124";
mystring = mystring.Substring(mystring.Length-4)

Freemarker iterating over hashmap keys

Edit: Don't use this solution with FreeMarker 2.3.25 and up, especially not .get(prop). See other answers.

You use the built-in keys function, e.g. this should work:

<#list user?keys as prop>
    ${prop} = ${user.get(prop)}
</#list>

Changing cell color using apache poi

For apache POI 3.9 you can use the code bellow:

HSSFCellStyle style = workbook.createCellStyle()
style.setFillForegroundColor(HSSFColor.YELLOW.index)
style.setFillPattern((short) FillPatternType.SOLID_FOREGROUND.ordinal())

The methods for 3.9 version accept short and you should pay attention to the inputs.

How do I get Flask to run on port 80?

Easiest and Best Solution

Save your .py file in a folder. This case my folder name is test. In the command prompt run the following

c:\test> set FLASK_APP=application.py
c:\test> set FLASK_RUN_PORT=8000
c:\test> flask run

----------------- Following will be returned ----------------

 * Serving Flask app "application.py"
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on http://127.0.0.1:8000/ (Press CTRL+C to quit)
127.0.0.1 - - [23/Aug/2019 09:40:04] "[37mGET / HTTP/1.1[0m" 200 -
127.0.0.1 - - [23/Aug/2019 09:40:04] "[33mGET /favicon.ico HTTP/1.1[0m" 404 -

Now on your browser type: http://127.0.0.1:8000. Thanks

Row count with PDO

fetchColumn()

used if want to get count of record [effisien]

$sql   = "SELECT COUNT(*) FROM fruit WHERE calories > 100";
$res   = $conn->query($sql);
$count = $res->fetchColumn(); // ex = 2

query()

used if want to retrieve data and count of record [options]

$sql = "SELECT * FROM fruit WHERE calories > 100";
$res = $conn->query($sql);

if ( $res->rowCount() > 0) {

    foreach ( $res as $row ) {
        print "Name: {$row['NAME']} <br />";
    }

}
else {
    print "No rows matched the query.";
}

PDOStatement::rowCount

Android ADB devices unauthorized

Your app is being detected as some harmful program. Turn off "Verify apps over USB" option. It's in the same view as "USB debugging".

How to improve Netbeans performance?

Very simple solution to the problem when your NetBeans or Eclipse IDE seems to be using too much memory:

Disable the plugins you are not using.
close the projects you are not working on.

I was facing similar problem with Netbeans 7.0 on my Linux Mint as well Ubuntu box. Netbeans was using > 700 MiB space and 50-80% CPU. Then I decided do some clean up. I had 30 plugins installed, and I was not using most of them. So, I disabled the plugins I was not using, a whopping 19 plug ins I disabled. now memory uses down to 400+ MiB and CPU uses down to 10 and at max to 50%.

Now my life is much easier.

The difference between "require(x)" and "import x"

Let me give an example for Including express module with require & import

-require

var express = require('express');

-import

import * as  express from 'express';

So after using any of the above statement we will have a variable called as 'express' with us. Now we can define 'app' variable as,

var app = express();

So we use 'require' with 'CommonJS' and 'import' with 'ES6'.

For more info on 'require' & 'import', read through below links.

require - Requiring modules in Node.js: Everything you need to know

import - An Update on ES6 Modules in Node.js

How to get the url parameters using AngularJS

When using angularjs with express

On my example I was using angularjs with express doing the routing so using $routeParams would mess up with my routing. I used the following code to get what I was expecting:

const getParameters = (temp, path) => {
  const parameters = {};
  const tempParts = temp.split('/');
  const pathParts = path.split('/');
  for (let i = 0; i < tempParts.length; i++) {
    const element = tempParts[i];
    if(element.startsWith(':')) {
      const key = element.substring(1,element.length);
      parameters[key] = pathParts[i];
    }
  }
  return parameters;
};

This receives a URL template and the path of the given location. The I just call it with:

const params = getParameters('/:table/:id/visit/:place_id/on/:interval/something', $location.path());

Putting it all together my controller is:

.controller('TestController', ['$scope', function($scope, $window) {
  const getParameters = (temp, path) => {
    const parameters = {};
    const tempParts = temp.split('/');
    const pathParts = path.split('/');
    for (let i = 0; i < tempParts.length; i++) {
      const element = tempParts[i];
      if(element.startsWith(':')) {
        const key = element.substring(1,element.length);
        parameters[key] = pathParts[i];
      }
    }
    return parameters;
  };

const params = getParameters('/:table/:id/visit/:place_id/on/:interval/something', $window.location.pathname);
}]);

The result will be:

{ table: "users", id: "1", place_id: "43", interval: "week" }

Hope this helps someone out there!

react-router - pass props to handler component

You can also combine es6 and stateless functions to get a much cleaner result:

import Dashboard from './Dashboard';
import Comments from './Comments';

let dashboardWrapper = () => <Dashboard {...props} />,
    commentsWrapper = () => <Comments {...props} />,
    index = () => <div>
        <header>Some header</header>
        <RouteHandler />
        {this.props.children}
    </div>;

routes = {
    component: index,
    path: '/',
    childRoutes: [
      {
        path: 'comments',
        component: dashboardWrapper
      }, {
        path: 'dashboard',
        component: commentsWrapper
      }
    ]
}

C# Remove object from list of objects

You're removing and then incrementing, which means you'll be one ahead of yourself. Instead, remove in reverse so you never mess up your next item.

for (int i = ChunkList.Count-1; i >=0; i--)
{
    if (ChunkList[i].UniqueID == ChunkID)
    {
        ChunkList.RemoveAt(i);
    }
}

Sorting a vector in descending order

bool comp(int i, int j) { return i > j; }
sort(numbers.begin(), numbers.end(), comp);

I need to round a float to two decimal places in Java

1.2975118E7 is scientific notation.

1.2975118E7 = 1.2975118 * 10^7 = 12975118

Also, Math.round(f) returns an integer. You can't use it to get your desired format x.xx.

You could use String.format.

String s = String.format("%.2f", 1.2975118);
// 1.30

'tsc command not found' in compiling typescript

The only solution that work for me was put npx tsc -v or for the compiling npx tsc salida.ts

"salida.ts" is the name of the file

Is it possible to run JavaFX applications on iOS, Android or Windows Phone 8?

Desktop: first-class support

Oracle JavaFX from Java SE supports only OS X (macOS), GNU/Linux and Microsoft Windows. On these platforms, JavaFX applications are typically run on JVM from Java SE or OpenJDK.

Android: should work

There is also a JavaFXPorts project, which is an open-source project sponsored by a third-party. It aims to port JavaFX library to Android and iOS.

On Android, this library can be used like any other Java library; the JVM bytecode is compiled to Dalvik bytecode. It's what people mean by saying that "Android runs Java".

iOS: status not clear

On iOS, situation is a bit more complex, as neither Java SE nor OpenJDK supports Apple mobile devices. Till recently, the only sensible option was to use RoboVM ahead-of-time Java compiler for iOS. Unfortunately, on 15 April 2015, RoboVM project was shut down.

One possible alternative is Intel's Multi-OS Engine. Till recently, it was a proprietary technology, but on 11 August 2016 it was open-sourced. Although it can be possible to compile an iOS JavaFX app using JavaFXPorts' JavaFX implementation, there is no evidence for that so far. As you can see, the situation is dynamically changing, and this answer will be hopefully updated when new information is available.

Windows Phone: no support

With Windows Phone it's simple: there is no JavaFX support of any kind.

How to find length of a string array?

As all the above answers have suggested it will throw a NullPointerException.

Please initialise it with some value(s) and then you can use the length property correctly. For example:

String[] str = { "plastic", "paper", "use", "throw" };
System.out.println("Length is:::" + str.length);

The array 'str' is now defined, and so it's length also has a defined value.

Getting "java.nio.file.AccessDeniedException" when trying to write to a folder

I was getting the same error when trying to copy a file. Closing a channel associated with the target file solved the problem.

Path destFile = Paths.get("dest file");
SeekableByteChannel destFileChannel = Files.newByteChannel(destFile);
//...
destFileChannel.close();  //removing this will throw java.nio.file.AccessDeniedException:
Files.copy(Paths.get("source file"), destFile);

Printing newlines with print() in R

An alternative to cat() is writeLines():

> writeLines("File not supplied.\nUsage: ./program F=filename")
File not supplied.
Usage: ./program F=filename
>

An advantage is that you don't have to remember to append a "\n" to the string passed to cat() to get a newline after your message. E.g. compare the above to the same cat() output:

> cat("File not supplied.\nUsage: ./program F=filename")
File not supplied.
Usage: ./program F=filename>

and

> cat("File not supplied.\nUsage: ./program F=filename","\n")
File not supplied.
Usage: ./program F=filename
>

The reason print() doesn't do what you want is that print() shows you a version of the object from the R level - in this case it is a character string. You need to use other functions like cat() and writeLines() to display the string. I say "a version" because precision may be reduced in printed numerics, and the printed object may be augmented with extra information, for example.

Create a simple Login page using eclipse and mysql

use this code it is working

// index.jsp or login.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>

<form action="login" method="post">
Username : <input type="text" name="username"><br>
Password : <input type="password" name="pass"><br>
<input type="submit"><br>
</form>

</body>
</html>

// authentication servlet class

    import java.io.IOException;
    import java.io.PrintWriter;
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.SQLException;
    import java.sql.Statement;

    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    public class auth extends HttpServlet {
        private static final long serialVersionUID = 1L;

        public auth() {
            super();
        }
        protected void doGet(HttpServletRequest request,
                HttpServletResponse response) throws ServletException, IOException {

        }

        protected void doPost(HttpServletRequest request,
                HttpServletResponse response) throws ServletException, IOException {

            try {
                Class.forName("com.mysql.jdbc.Driver");
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }

            String username = request.getParameter("username");
            String pass = request.getParameter("pass");

            String sql = "select * from reg where username='" + username + "'";
            Connection conn = null;

            try {
                conn = DriverManager.getConnection("jdbc:mysql://localhost/Exam",
                        "root", "");
                Statement s = conn.createStatement();

                java.sql.ResultSet rs = s.executeQuery(sql);
                String un = null;
                String pw = null;
                String name = null;

            /* Need to put some condition in case the above query does not return any row, else code will throw Null Pointer exception */   

            PrintWriter prwr1 = response.getWriter();               
            if(!rs.isBeforeFirst()){
                prwr1.write("<h1> No Such User in Database<h1>");
            } else {

/* Conditions to be executed after at least one row is returned by query execution */ 
                while (rs.next()) {
                    un = rs.getString("username");
                    pw = rs.getString("password");
                    name = rs.getString("name");
                }

                PrintWriter pww = response.getWriter();

                if (un.equalsIgnoreCase(username) && pw.equals(pass)) {
                                // use this or create request dispatcher 
                    response.setContentType("text/html");
                    pww.write("<h1>Welcome, " + name + "</h1>");
                } else {
                    pww.write("wrong username or password\n");
                }
              }

            } catch (SQLException e) {
                e.printStackTrace();
            }

        }

    }

jQuery Call to WebService returns "No Transport" error

Add this: jQuery.support.cors = true;

It enables cross-site scripting in jQuery (introduced after 1.4x, I believe).

We were using a really old version of jQuery (1.3.2) and swapped it out for 1.6.1. Everything was working, except .ajax() calls. Adding the above line fixed the problem.

Determine the number of rows in a range

Why not use an Excel formula to determine the rows? For instance, if you are looking for how many cells contain data in Column A use this:

=COUNTIFS(A:A,"<>")

You can replace <> with any value to get how many rows have that value in it.

=COUNTIFS(A:A,"2008")

This can be used for finding filled cells in a row too.

Define preprocessor macro through CMake?

For a long time, CMake had the add_definitions command for this purpose. However, recently the command has been superseded by a more fine grained approach (separate commands for compile definitions, include directories, and compiler options).

An example using the new add_compile_definitions:

add_compile_definitions(OPENCV_VERSION=${OpenCV_VERSION})
add_compile_definitions(WITH_OPENCV2)

Or:

add_compile_definitions(OPENCV_VERSION=${OpenCV_VERSION} WITH_OPENCV2)

The good part about this is that it circumvents the shabby trickery CMake has in place for add_definitions. CMake is such a shabby system, but they are finally finding some sanity.

Find more explanation on which commands to use for compiler flags here: https://cmake.org/cmake/help/latest/command/add_definitions.html

Likewise, you can do this per-target as explained in Jim Hunziker's answer.

SQL Server 2000: How to exit a stored procedure?

Its because you have no BEGIN and END statements. You shouldn't be seeing the prints, or errors running this statement, only Statement Completed (or something like that).

When should I use Memcache instead of Memcached?

This is 2013. Forget about the 2009 comments. Likewise, if you are running serious traffic loads, do not even contemplate how to make-do with a windows based memcache. When dealing with a very large scale (500+ front end web servers) and 20+ back end database servers and replicants (mysql & mssql mix), a farm of memcached servers (12 servers in group) supports multiple high volume OLTP applications answering 25K ~ 40K mc->get calls per-second. These calls are those that do NOT have to reach a database.

IMHO, this use of memcached provided SERIOUS $$$,$$$savings on CAPEX for new DB servers & licences as well as on support contracts for large commercial designs.

replace NULL with Blank value or Zero in sql server

Replace Null Values as Empty: ISNULL('Value','')

Replace Null Values as 0: ISNULL('Value',0)

What is the most "pythonic" way to iterate over a list in chunks?

With NumPy it's simple:

ints = array([1, 2, 3, 4, 5, 6, 7, 8])
for int1, int2 in ints.reshape(-1, 2):
    print(int1, int2)

output:

@UniqueConstraint annotation in Java

To ensure a field value is unique you can write

@Column(unique=true)
String username;

The @UniqueConstraint annotation is for annotating multiple unique keys at the table level, which is why you get an error when applying it to a field.

References (JPA TopLink):

Is there a command to undo git init?

remove the .git folder in your project root folder

if you installed submodules and want to remove their git, also remove .git from submodules folders

Creating a SearchView that looks like the material design guidelines

The following will create a SearchView identical to the one in Gmail and add it to the given Toolbar. You'll just have to implement your own "ViewUtil.convertDpToPixel" method.

private SearchView createMaterialSearchView(Toolbar toolbar, String hintText) {

    setSupportActionBar(toolbar);
    ActionBar actionBar = getSupportActionBar();
    actionBar.setDisplayHomeAsUpEnabled(true);
    actionBar.setDisplayShowCustomEnabled(true);
    actionBar.setDisplayShowTitleEnabled(false);

    SearchView searchView = new SearchView(this);
    searchView.setIconifiedByDefault(false);
    searchView.setMaxWidth(Integer.MAX_VALUE);
    searchView.setMinimumHeight(Integer.MAX_VALUE);
    searchView.setQueryHint(hintText);

    int rightMarginFrame = 0;
    View frame = searchView.findViewById(getResources().getIdentifier("android:id/search_edit_frame", null, null));
    if (frame != null) {
        LinearLayout.LayoutParams frameParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        rightMarginFrame = ((LinearLayout.LayoutParams) frame.getLayoutParams()).rightMargin;
        frameParams.setMargins(0, 0, 0, 0);
        frame.setLayoutParams(frameParams);
    }

    View plate = searchView.findViewById(getResources().getIdentifier("android:id/search_plate", null, null));
    if (plate != null) {
        plate.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        plate.setPadding(0, 0, rightMarginFrame, 0);
        plate.setBackgroundColor(Color.TRANSPARENT);
    }

    int autoCompleteId = getResources().getIdentifier("android:id/search_src_text", null, null);
    if (searchView.findViewById(autoCompleteId) != null) {
        EditText autoComplete = (EditText) searchView.findViewById(autoCompleteId);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0, (int) ViewUtil.convertDpToPixel(36));
        params.weight = 1;
        params.gravity = Gravity.CENTER_VERTICAL;
        params.leftMargin = rightMarginFrame;
        autoComplete.setLayoutParams(params);
        autoComplete.setTextSize(16f);
    }

    int searchMagId = getResources().getIdentifier("android:id/search_mag_icon", null, null);
    if (searchView.findViewById(searchMagId) != null) {
        ImageView v = (ImageView) searchView.findViewById(searchMagId);
        v.setImageDrawable(null);
        v.setPadding(0, 0, 0, 0);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        params.setMargins(0, 0, 0, 0);
        v.setLayoutParams(params);
    }

    toolbar.setTitle(null);
    toolbar.setContentInsetsAbsolute(0, 0);
    toolbar.addView(searchView);

    return searchView;
}

Check if an image is loaded (no errors) with jQuery

Based on my understanding of the W3C HTML Specification for the img element, you should be able to do this using a combination of the complete and naturalHeight attributes, like so:

function imgLoaded(imgElement) {
  return imgElement.complete && imgElement.naturalHeight !== 0;
}

From the spec for the complete attribute:

The IDL attribute complete must return true if any of the following conditions is true:

The src attribute is omitted.

The final task that is queued by the networking task source once the resource has been fetched has been queued.

The img element is completely available.

The img element is broken.

Otherwise, the attribute must return false.

So essentially, complete returns true if the image has either finished loading, or failed to load. Since we want only the case where the image successfully loaded we need to check the nauturalHeight attribute as well:

The IDL attributes naturalWidth and naturalHeight must return the intrinsic width and height of the image, in CSS pixels, if the image is available, or else 0.

And available is defined like so:

An img is always in one of the following states:

Unavailable - The user agent hasn't obtained any image data.

Partially available - The user agent has obtained some of the image data.

Completely available - The user agent has obtained all of the image data and at least the image dimensions are available.

Broken - The user agent has obtained all of the image data that it can, but it cannot even decode the image enough to get the image dimensions (e.g. the image is corrupted, or the format is not supported, or no data could be obtained).

When an img element is either in the partially available state or in the completely available state, it is said to be available.

So if the image is "broken" (failed to load), then it will be in the broken state, not the available state, so naturalHeight will be 0.

Therefore, checking imgElement.complete && imgElement.naturalHeight !== 0 should tell us whether the image has successfully loaded.

You can read more about this in the W3C HTML Specification for the img element, or on MDN.

Creating Dynamic button with click event in JavaScript

this:

element.setAttribute("onclick", alert("blabla"));

should be:

element.onclick = function () {
  alert("blabla");
}

Because you call alert instead push alert as string in attribute

SQL Server insert if not exists best practice

Additionally, if you have multiple columns to insert and want to check if they exists or not use the following code

Insert Into [Competitors] (cName, cCity, cState)
Select cName, cCity, cState from 
(
    select new.* from 
    (
        select distinct cName, cCity, cState 
        from [Competitors] s, [City] c, [State] s
    ) new
    left join 
    (   
        select distinct cName, cCity, cState 
        from [Competitors] s
    ) existing
    on new.cName = existing.cName and new.City = existing.City and new.State = existing.State
    where existing.Name is null  or existing.City is null or existing.State is null
)

jQuery hyperlinks - href value?

You should really put a real link in there. I don't want to sound like a pedant, but that's a fairly bad habit to get into. JQuery and Ajax should always be the last thing you implement. If you have a link that goes no-where, you're not doing it right.

I'm not busting your balls, I mean that with all the best intention.

Python Pandas Counting the Occurrences of a Specific value

for finding a specific value of a column you can use the code below

irrespective of the preference you can use the any of the method you like

df.col_name.value_counts().Value_you_are_looking_for

take example of the titanic dataset

df.Sex.value_counts().male

this gives a count of all male on the ship Although if you want to count a numerical data then you cannot use the above method because value_counts() is used only with series type of data hence fails So for that you can use the second method example

the second method is

#this is an example method of counting on a data frame
df[(df['Survived']==1)&(df['Sex']=='male')].counts()

this is not that efficient as value_counts() but surely will help if you want to count values of a data frame hope this helps

How to install a specific version of Node on Ubuntu?

version 0.10 is also avaible with this ppa

apt-add-repository ppa:chris-lea/node.js

install nodejs with:

apt-get install nodejs=0.10.25-1chl1~precise1

Thanks to my friend Julian Xhokaxhiu

How to decode viewstate

Use Fiddler and grab the view state in the response and paste it into the bottom left text box then decode.

R: Break for loop

your break statement should break out of the for (in in 1:n).

Personally I am always wary with break statements and double check it by printing to the console to double check that I am in fact breaking out of the right loop. So before you test add the following statement, which will let you know if you break before it reaches the end. However, I have no idea how you are handling the variable n so I don't know if it would be helpful to you. Make a n some test value where you know before hand if it is supposed to break out or not before reaching n.

for (in in 1:n)
{
    if (in == n)         #add this statement
    {
        "sorry but the loop did not break"
    }

    id_novo <- new_table_df$ID[in]
    if(id_velho==id_novo)
    {
        break
    }
    else if(in == n)
    {
        sold_df <- rbind(sold_df,old_table_df[out,])
    }
}

Excel add one hour

In cell A1, enter the time.
In cell B2, enter =A1+1/24

How to access ssis package variables inside script component

This should work:

IDTSVariables100 vars = null;
VariableDispenser.LockForRead("System::TaskName");
VariableDispenser.GetVariables(vars);
string TaskName = vars("System::TaskName").Value.ToString();
vars.Unlock();

Your initial code lacks call of the GetVariables() method.

How do I deserialize a complex JSON object in C# .NET?

I had a scenario, and this one helped me

JObject objParserd = JObject.Parse(jsonString);

JObject arrayObject1 = (JObject)objParserd["d"];

D myOutput= JsonConvert.DeserializeObject<D>(arrayObject1.ToString());

How to set Oracle's Java as the default Java in Ubuntu?

If you want to use specific version of Java when multiple JDKs are installed, just setting JAVA_HOME may not work.

You need to use sudo update-alternatives --config java to set default Java.

Refer to https://askubuntu.com/questions/121654/how-to-set-default-java-version.

bootstrap initially collapsed element

When you expand or collapse accordion it just adds/removes a class "in" and sets the height:auto or 0 to the accordion div.

Demo

So in your accordion when you define it just remove "in" class from the div as below. Whenever you expand an accorion it just adds the "in" class to make it visible.

If you render the page with "in" bootstrap looks for the class and it will make the div's height:auto, if it not present it will be at zero height.

<div id="collapseOne" class="accordion-body collapse">

Visual Studio Code: Auto-refresh file changes

SUPER-SHIFT-p > File: Revert File is the only way

(where SUPER is Command on Mac and Ctrl on PC)

Static variables in JavaScript

You can think like this. Into the <body></body> place a tag <p id='staticVariable'></p> and set its visibility: hide.

Of course you can manage the text inside the previous tag by using jquery. Pratically this tag become your static variable.

Slidedown and slideup layout with animation

Above method is working, but here are more realistic slide up and slide down animations from the top of the screen.

Just create these two animations under the anim folder

slide_down.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="200"
        android:fromYDelta="-100%"
        android:toYDelta="0" />
</set>

slide_up.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="200"
        android:fromYDelta="0"
        android:toYDelta="-100%" />
</set>

Load animation in java class like this

imageView.startAnimation(AnimationUtils.loadAnimation(getContext(),R.anim.slide_up));
imageView.startAnimation(AnimationUtils.loadAnimation(getContext(),R.anim.slide_down));

C/C++ macro string concatenation

If they're both strings you can just do:

#define STR3 STR1 STR2

This then expands to:

#define STR3 "s" "1"

and in the C language, separating two strings with space as in "s" "1" is exactly equivalent to having a single string "s1".

HTML5 - mp4 video does not play in IE9

Try the following and see if it works:

<video width="400" height="300" preload controls>
  <source src="video.mp4" type="video/mp4" />
  Your browser does not support the video tag.
</video>

When is the finalize() method called in Java?

Java allows objects to implement a method called finalize() that might get called.

finalize() method gets called if the garbage collector tries to collect the object.

If the garbage collector doesn't run, the method doesn't get called.

If the garbage collector fails to collect the object and tries to run it again, the method doesn't get called in the second time.

In practice, you are highly unlikely to use it in real projects.

Just keep in mind that it might not get called and that it definitely won't be called twice. The finalize() method could run zero or one time.

In the following code, finalize() method produces no output when we run it since the program exits before there is any need to run the garbage collector.

Source

Convert DateTime to TimeSpan

Try the following code.

 TimeSpan CurrentTime = DateTime.Now.TimeOfDay;

Get the time of the day and assign it to TimeSpan variable.

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

Json.NET does this...

Dictionary<string, string> values = new Dictionary<string, string>();
values.Add("key1", "value1");
values.Add("key2", "value2");

string json = JsonConvert.SerializeObject(values);
// {
//   "key1": "value1",
//   "key2": "value2"
// }

More examples: Serializing Collections with Json.NET

Get JSONArray without array name?

Here is a solution under 19API lvl:

First of all. Make a Gson obj. --> Gson gson = new Gson();
Second step is get your jsonObj as String with StringRequest(instead of JsonObjectRequest)
The last step to get JsonArray...

YoursObjArray[] yoursObjArray = gson.fromJson(response, YoursObjArray[].class);

typescript - cloning object

For a simple clone of the hole object's content, I simply stringify and parse the instance :

let cloneObject = JSON.parse(JSON.stringify(objectToClone))

Whereas I change data in objectToClone tree, there is no change in cloneObject. That was my requierement.

Hope it help

How to reset the state of a Redux store?

Simply have your logout link clear session and refresh the page. No additional code needed for your store. Any time you want to completely reset the state a page refresh is a simple and easily repeatable way to handle it.

PHP - Check if the page run on Mobile or Desktop browser

I used Robert Lee`s answer and it works great! Just writing down the complete function i'm using:

function isMobileDevice(){
    $aMobileUA = array(
        '/iphone/i' => 'iPhone', 
        '/ipod/i' => 'iPod', 
        '/ipad/i' => 'iPad', 
        '/android/i' => 'Android', 
        '/blackberry/i' => 'BlackBerry', 
        '/webos/i' => 'Mobile'
    );

    //Return true if Mobile User Agent is detected
    foreach($aMobileUA as $sMobileKey => $sMobileOS){
        if(preg_match($sMobileKey, $_SERVER['HTTP_USER_AGENT'])){
            return true;
        }
    }
    //Otherwise return false..  
    return false;
}

Unzipping files

Code example is given on the author site's. You can use babelfish to translate the texts (Japanese to English).

As far as I understand Japanese, this zip inflate code is meant to decode ZIP data (streams) not ZIP archive.

Plotting with C#

NPlot is a pretty good simple open source 2D plotting API. Unfortunately, the web site is down. I don't know if this is just temporary or not. I haven't heard of any bad news. It may come back up.

http://www.nplot.com

Here is an article describing it:

http://aspnet.4guysfromrolla.com/articles/072507-1.aspx

The previous article uses VB.NET, but obviously this will work with C#.

Again, not sure why nplot's site is not currently working but it is a somewhat popular plotting API that I've used in the past. I post it for your information and in case of the likely event nplot will be back up soon. :)

Edit:

Thanks to a Hosam Aly, it looks like the SourceForge project can still be accessed here:

http://sourceforge.net/projects/nplot

postgresql duplicate key violates unique constraint

The primary key is already protecting you from inserting duplicate values, as you're experiencing when you get that error. Adding another unique constraint isn't necessary to do that.

The "duplicate key" error is telling you that the work was not done because it would produce a duplicate key, not that it discovered a duplicate key already commited to the table.

'Malformed UTF-8 characters, possibly incorrectly encoded' in Laravel

Set the charset at after you made the connection to db like

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

if (!$conn->set_charset("utf8")) {
    printf("Error loading character set utf8: %s\n", $conn->error);
    exit();
} else {
    printf("Current character set: %s\n", $conn->character_set_name());
}

C++ - how to find the length of an integer

How about (works also for 0 and negatives):

int digits( int x ) { 
    return ( (bool) x * (int) log10( abs( x ) ) + 1 );
}

How do you convert CString and std::string std::wstring to each other?

According to CodeGuru:

CString to std::string:

CString cs("Hello");
std::string s((LPCTSTR)cs);

BUT: std::string cannot always construct from a LPCTSTR. i.e. the code will fail for UNICODE builds.

As std::string can construct only from LPSTR / LPCSTR, a programmer who uses VC++ 7.x or better can utilize conversion classes such as CT2CA as an intermediary.

CString cs ("Hello");
// Convert a TCHAR string to a LPCSTR
CT2CA pszConvertedAnsiString (cs);
// construct a std::string using the LPCSTR input
std::string strStd (pszConvertedAnsiString);

std::string to CString: (From Visual Studio's CString FAQs...)

std::string s("Hello");
CString cs(s.c_str());

CStringT can construct from both character or wide-character strings. i.e. It can convert from char* (i.e. LPSTR) or from wchar_t* (LPWSTR).

In other words, char-specialization (of CStringT) i.e. CStringA, wchar_t-specilization CStringW, and TCHAR-specialization CString can be constructed from either char or wide-character, ~~null terminated (null-termination is very important here)~~ string sources.
Althoug IInspectable amends the "null-termination" part in the comments:

NUL-termination is not required.
CStringT has conversion constructors that take an explicit length argument. This also means that you can construct CStringT objects from std::string objects with embedded NUL characters.

Remove all padding and margin table HTML and CSS

Use a display block

style= "display: block";

How do I do a simple 'Find and Replace" in MsSQL?

The following will find and replace a string in every database (excluding system databases) on every table on the instance you are connected to:

Simply change 'Search String' to whatever you seek and 'Replace String' with whatever you want to replace it with.

--Getting all the databases and making a cursor
DECLARE db_cursor CURSOR FOR  
SELECT name 
FROM master.dbo.sysdatabases 
WHERE name NOT IN ('master','model','msdb','tempdb')  -- exclude these databases

DECLARE @databaseName nvarchar(1000)
--opening the cursor to move over the databases in this instance
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO @databaseName   

WHILE @@FETCH_STATUS = 0   
BEGIN
    PRINT @databaseName
    --Setting up temp table for the results of our search
    DECLARE @Results TABLE(TableName nvarchar(370), RealColumnName nvarchar(370), ColumnName nvarchar(370), ColumnValue nvarchar(3630))

    SET NOCOUNT ON

    DECLARE @SearchStr nvarchar(100), @ReplaceStr nvarchar(100), @SearchStr2 nvarchar(110)
    SET @SearchStr = 'Search String'
    SET @ReplaceStr = 'Replace String'
    SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

    DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128)
    SET  @TableName = ''

    --Looping over all the tables in the database
    WHILE @TableName IS NOT NULL
    BEGIN
        DECLARE @SQL nvarchar(2000)
        SET @ColumnName = ''
        DECLARE @result NVARCHAR(256)
        SET @SQL = 'USE ' + @databaseName + '
            SELECT @result = MIN(QUOTENAME(TABLE_SCHEMA) + ''.'' + QUOTENAME(TABLE_NAME))
            FROM    [' + @databaseName + '].INFORMATION_SCHEMA.TABLES
            WHERE       TABLE_TYPE = ''BASE TABLE'' AND TABLE_CATALOG = ''' + @databaseName + '''
                AND QUOTENAME(TABLE_SCHEMA) + ''.'' + QUOTENAME(TABLE_NAME) > ''' + @TableName + '''
                AND OBJECTPROPERTY(
                        OBJECT_ID(
                            QUOTENAME(TABLE_SCHEMA) + ''.'' + QUOTENAME(TABLE_NAME)
                                ), ''IsMSShipped''
                                ) = 0'
        EXEC master..sp_executesql @SQL, N'@result nvarchar(256) out', @result out

        SET @TableName = @result
        PRINT @TableName

        WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
        BEGIN
            DECLARE @ColumnResult NVARCHAR(256)
            SET @SQL = '
                SELECT @ColumnResult = MIN(QUOTENAME(COLUMN_NAME))
                FROM    [' + @databaseName + '].INFORMATION_SCHEMA.COLUMNS
                WHERE       TABLE_SCHEMA    = PARSENAME(''[' + @databaseName + '].' + @TableName + ''', 2)
                    AND TABLE_NAME  = PARSENAME(''[' + @databaseName + '].' + @TableName + ''', 1)
                    AND DATA_TYPE IN (''char'', ''varchar'', ''nchar'', ''nvarchar'')
                    AND TABLE_CATALOG = ''' + @databaseName + '''
                    AND QUOTENAME(COLUMN_NAME) > ''' + @ColumnName + ''''
            PRINT @SQL
            EXEC master..sp_executesql @SQL, N'@ColumnResult nvarchar(256) out', @ColumnResult out
            SET @ColumnName = @ColumnResult 

            PRINT @ColumnName

            IF @ColumnName IS NOT NULL
            BEGIN
                INSERT INTO @Results
                EXEC
                (
                    'USE ' + @databaseName + '
                    SELECT ''' + @TableName + ''',''' + @ColumnName + ''',''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) 
                    FROM ' + @TableName + ' (NOLOCK) ' +
                    ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
                )
            END
        END
    END

    --Declaring another temporary table
    DECLARE @time_to_update TABLE(TableName nvarchar(370), RealColumnName nvarchar(370))

    INSERT INTO @time_to_update
    SELECT TableName, RealColumnName FROM @Results GROUP BY TableName, RealColumnName

    DECLARE @MyCursor CURSOR;
    BEGIN
        DECLARE @t nvarchar(370)
        DECLARE @c nvarchar(370)
        --Looping over the search results   
        SET @MyCursor = CURSOR FOR
        SELECT TableName, RealColumnName FROM @time_to_update GROUP BY TableName, RealColumnName

        --Getting my variables from the first item
        OPEN @MyCursor 
        FETCH NEXT FROM @MyCursor 
        INTO @t, @c

        WHILE @@FETCH_STATUS = 0
        BEGIN
            -- Updating the old values with the new value
            DECLARE @sqlCommand varchar(1000)
            SET @sqlCommand = '
                USE ' + @databaseName + '
                UPDATE [' + @databaseName + '].' + @t + ' SET ' + @c + ' = REPLACE(' + @c + ', ''' + @SearchStr + ''', ''' + @ReplaceStr + ''') 
                WHERE ' + @c + ' LIKE ''' + @SearchStr2 + ''''
            PRINT @sqlCommand
            BEGIN TRY
                EXEC (@sqlCommand)
            END TRY
            BEGIN CATCH
                PRINT ERROR_MESSAGE()
            END CATCH

            --Getting next row values
            FETCH NEXT FROM @MyCursor 
            INTO @t, @c 
        END;

        CLOSE @MyCursor ;
        DEALLOCATE @MyCursor;
    END;

    DELETE FROM @time_to_update
    DELETE FROM @Results

    FETCH NEXT FROM db_cursor INTO @databaseName
END   

CLOSE db_cursor   
DEALLOCATE db_cursor

Note: this isn't ideal, nor is it optimized

How do I write outputs to the Log in Android?

String one = object.getdata();
Log.d(one,"");

How can I avoid getting this MySQL error Incorrect column specifier for column COLUMN NAME?

I was having the same problem, but using Long type. I changed for INT and it worked for me.

CREATE TABLE lists (
 id INT NOT NULL AUTO_INCREMENT,
 desc varchar(30),
 owner varchar(20),
 visibility boolean,
 PRIMARY KEY (id)
 );

Request Permission for Camera and Library in iOS 10 - Info.plist

Use the plist settings mentioned above and the appropriate accessor (AVCaptureDevice or PHPhotoLibrary), but also alert them and send them to settings if you really need this, like so:

Swift 4.0 and 4.1

func proceedWithCameraAccess(identifier: String){
    // handler in .requestAccess is needed to process user's answer to our request
    AVCaptureDevice.requestAccess(for: .video) { success in
      if success { // if request is granted (success is true)
        DispatchQueue.main.async {
          self.performSegue(withIdentifier: identifier, sender: nil)
        }
      } else { // if request is denied (success is false)
        // Create Alert
        let alert = UIAlertController(title: "Camera", message: "Camera access is absolutely necessary to use this app", preferredStyle: .alert)

        // Add "OK" Button to alert, pressing it will bring you to the settings app
        alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { action in
          UIApplication.shared.open(URL(string: UIApplicationOpenSettingsURLString)!)
        }))
        // Show the alert with animation
        self.present(alert, animated: true)
      }
    }
  }

How to print an exception in Python?

One liner error raising can be done with assert statements if that's what you want to do. This will help you write statically fixable code and check errors early.

assert type(A) is type(""), "requires a string"

Java2D: Increase the line width

You should use setStroke to set a stroke of the Graphics2D object.

The example at http://www.java2s.com gives you some code examples.

The following code produces the image below:

import java.awt.*;
import java.awt.geom.Line2D;
import javax.swing.*;

public class FrameTest {
    public static void main(String[] args) {
        JFrame jf = new JFrame("Demo");
        Container cp = jf.getContentPane();
        cp.add(new JComponent() {
            public void paintComponent(Graphics g) {
                Graphics2D g2 = (Graphics2D) g;
                g2.setStroke(new BasicStroke(10));
                g2.draw(new Line2D.Float(30, 20, 80, 90));
            }
        });
        jf.setSize(300, 200);
        jf.setVisible(true);
    }
}

enter image description here

(Note that the setStroke method is not available in the Graphics object. You have to cast it to a Graphics2D object.)

This post has been rewritten as an article here.

How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?

Using DirectoryIterator and recursion correctly:

function deleteFilesThenSelf($folder) {
    foreach(new DirectoryIterator($folder) as $f) {
        if($f->isDot()) continue; // skip . and ..
        if ($f->isFile()) {
            unlink($f->getPathname());
        } else if($f->isDir()) {
            deleteFilesThenSelf($f->getPathname());
        }
    }
    rmdir($folder);
}

How to add a "open git-bash here..." context menu to the windows explorer?

As, @Shaswat Rungta said: "I think the question is more about how to add it after the installation is over."

On my PC(Windows 7) I think that the command "Git Bash here" disappeard after I installed Visual Studio 2017.

I fixt this by downloading and installing Git again.

NOTE: "When installing Git for Windows the context menu options are not 'on' by default. You will have to select them during the install." – @nbushnell (I did this)

Adding Python Path on Windows 7

Working with Windows environment variables is always a horrible experience. Recently, I found an amazing tool called Rapid Environment Editor, which gives an awesomely simple GUI for managing them.

If you use chocolatey, you can install it using choco install rapidee. Otherwise, take a look at http://www.rapidee.com/en/download

Re-reading this, it sounds like a paid shill, but I swear I'm not! It's just been one of the most useful utilities in my toolkit for a while and I'm surprised no one seems to know about it.

How do I find a list of Homebrew's installable packages?

From the man page:

search, -S text|/text/
Perform a substring search of formula names for text. If text is surrounded with slashes,
then it is interpreted as a regular expression. If no search term is given,
all available formula are displayed.

For your purposes, brew search will suffice.

How to make node.js require absolute? (instead of relative)

Whilst these answers work they do not address the problem with npm test

If, for example, I create a global variable in server.js, it will not be set for my test suite execution.

To set a global appRoot variable that will avoid the ../../../ problem and will be available in both npm start AND npm test see:

Mocha tests with extra options or parameters

Note that this is the new official mocha solution.

How to convert a string of bytes into an int?

I use the following function to convert data between int, hex and bytes.

def bytes2int(str):
 return int(str.encode('hex'), 16)

def bytes2hex(str):
 return '0x'+str.encode('hex')

def int2bytes(i):
 h = int2hex(i)
 return hex2bytes(h)

def int2hex(i):
 return hex(i)

def hex2int(h):
 if len(h) > 1 and h[0:2] == '0x':
  h = h[2:]

 if len(h) % 2:
  h = "0" + h

 return int(h, 16)

def hex2bytes(h):
 if len(h) > 1 and h[0:2] == '0x':
  h = h[2:]

 if len(h) % 2:
  h = "0" + h

 return h.decode('hex')

Source: http://opentechnotes.blogspot.com.au/2014/04/convert-values-to-from-integer-hex.html

HTML image not showing in Gmail

In addition to what was said by Howard

You have to keep in mind that Google encodes spaces as + To avoid this, the ulr must be encoded in RFC 3986, which means spaces encoded at %20, for example:

https://example.com/My Folder/image 1.jpg to https://example.com/My%20Folder/image%201.jpg

How to trim a string after a specific character in java

Use a Scanner and pass in the delimiter and the original string:

result = new Scanner(result).useDelimiter("\n").next();

Share data between AngularJS controllers

As pointed out by @MaNn in one of the comments of the accepted answers, the solution wont work if the page is refreshed.

The Solution for this is to use localStorage or sessionStorage for temporary persistence of the data you want to share across controllers.

Either you make a sessionService whose GET and SET method, encrypts and decrypts the data and reads the data from either localStorage or sessionStorage. So now you use this service directly to read and write the data in the storage via any controller or service you want. This is a open approach and easy one
Else you make a DataSharing Service and use localStorage inside it - so that if the page is refreshed the service will try and check the storage and reply back via the Getters and Setters you have made public or private in this service file.

Detecting locked tables (locked by LOCK TABLE)

You can use SHOW OPEN TABLES to show each table's lock status. More details on the command's doc page are here.

How to store Emoji Character in MySQL Database

Hi my friends This is how I solved this problem and I was happy to teach it to you as well I am in the Android application I encrypt a string containing text and emoj and send it to the server and save it in the mysql table and after receiving it from the server I decrypt it and display it in the textview. encoded and decoded my message before request and after response: I send Android app messages to mysql via pdo through this method and receive them with pdo. And I have no problem. I think it was a good way. Please like Thankful

_x000D_

 
 public void main()
 {
    String message="hi mester ali moradi ?? how are you ?";
    String encoded_message=encodeStringUrl(message);
    String decode_message=decodeStringUrl(encoded_message);
 }
 public static String encodeStringUrl(String message) {
        String encodedUrl =null;
        try {
            encodedUrl = URLEncoder.encode(message, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            return encodedUrl;
        }
        return encodedUrl;
    }

    public static String decodeStringUrl(String message) {
        String decodedUrl =null;
        try {
            decodedUrl = URLDecoder.decode(message, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            return decodedUrl;
        }
        return decodedUrl;
    }

_x000D_

_x000D_ message : hi mester ali moradi ?? how are you ? encoded : ghgh%F0%9F%98%AE%F0%9F%A4%90%F0%9F%98%A5 decoded :hi mester ali moradi ?? how are you ?

add a temporary column with a value

You mean staticly define a value, like this:

SELECT field1, 
       field2,
       'example' AS newfield
  FROM TABLE1

This will add a column called "newfield" to the output, and its value will always be "example".

How to clear PermGen space Error in tomcat

To complement Michael's answer, and according to this answer, a safe way to deal with the problem is to use the following arguments:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:+UseConcMarkSweepGC

How to remove space from string?

A funny way to remove all spaces from a variable is to use printf:

$ myvar='a cool variable    with   lots of   spaces in it'
$ printf -v myvar '%s' $myvar
$ echo "$myvar"
acoolvariablewithlotsofspacesinit

It turns out it's slightly more efficient than myvar="${myvar// /}", but not safe regarding globs (*) that can appear in the string. So don't use it in production code.

If you really really want to use this method and are really worried about the globbing thing (and you really should), you can use set -f (which disables globbing altogether):

$ ls
file1  file2
$ myvar='  a cool variable with spaces  and  oh! no! there is  a  glob  *  in it'
$ echo "$myvar"
  a cool variable with spaces  and  oh! no! there is  a  glob  *  in it
$ printf '%s' $myvar ; echo
acoolvariablewithspacesandoh!no!thereisaglobfile1file2init
$ # See the trouble? Let's fix it with set -f:
$ set -f
$ printf '%s' $myvar ; echo
acoolvariablewithspacesandoh!no!thereisaglob*init
$ # Since we like globbing, we unset the f option:
$ set +f

I posted this answer just because it's funny, not to use it in practice.

Traits vs. interfaces

An interface is a contract that says “this object is able to do this thing”, whereas a trait is giving the object the ability to do the thing.

A trait is essentially a way to “copy and paste” code between classes.

Try reading this article, What are PHP traits?

Case insensitive comparison NSString

 NSString *stringA;
 NSString *stringB;

 if (stringA && [stringA caseInsensitiveCompare:stringB] == NSOrderedSame) {
     // match
 }

Note: stringA && is required because when stringA is nil:

 stringA = nil;
 [stringA caseInsensitiveCompare:stringB] // return 0

and so happens NSOrderedSame is also defined as 0.

The following example is a typical pitfall:

 NSString *rank = [[NSUserDefaults standardUserDefaults] stringForKey:@"Rank"];
 if ([rank caseInsensitiveCompare:@"MANAGER"] == NSOrderedSame) {
     // what happens if "Rank" is not found in standardUserDefaults
 }

How to BULK INSERT a file into a temporary table where the filename is a variable?

Sorry to dig up an old question but in case someone stumbles onto this thread and wants a quicker solution.

Bulk inserting a unknown width file with \n row terminators into a temp table that is created outside of the EXEC statement.

DECLARE     @SQL VARCHAR(8000)

IF OBJECT_ID('TempDB..#BulkInsert') IS NOT NULL
BEGIN
    DROP TABLE #BulkInsert
END

CREATE TABLE #BulkInsert
(
    Line    VARCHAR(MAX)
)

SET @SQL = 'BULK INSERT #BulkInser FROM ''##FILEPATH##'' WITH (ROWTERMINATOR = ''\n'')'
EXEC (@SQL)

SELECT * FROM #BulkInsert

Further support that dynamic SQL within an EXEC statement has access to temp tables outside of the EXEC statement. http://sqlfiddle.com/#!3/d41d8/19343

DECLARE     @SQL VARCHAR(8000)

IF OBJECT_ID('TempDB..#BulkInsert') IS NOT NULL
BEGIN
    DROP TABLE #BulkInsert
END

CREATE TABLE #BulkInsert
(
    Line    VARCHAR(MAX)
)
INSERT INTO #BulkInsert
(
    Line
)
SELECT 1
UNION SELECT 2
UNION SELECT 3

SET @SQL = 'SELECT * FROM #BulkInsert'
EXEC (@SQL)

Further support, written for MSSQL2000 http://technet.microsoft.com/en-us/library/aa175921(v=sql.80).aspx

Example at the bottom of the link

DECLARE @cmd VARCHAR(1000), @ExecError INT
CREATE TABLE #ErrFile (ExecError INT)
SET @cmd = 'EXEC GetTableCount ' + 
'''pubs.dbo.authors''' + 
'INSERT #ErrFile VALUES(@@ERROR)'
EXEC(@cmd)
SET @ExecError = (SELECT * FROM #ErrFile)
SELECT @ExecError AS '@@ERROR'

Using Thymeleaf when the value is null

The shortest way! it's working for me, Where NA is my default value.

<td th:text="${ins.eValue!=null}? ${ins.eValue}:'NA'" />

How to add new contacts in android

Here I am posting a piece of code that i use to add a new contact. It works fine for me. I hope it will help you.

 String DisplayName = "XYZ";
 String MobileNumber = "123456";
 String HomeNumber = "1111";
 String WorkNumber = "2222";
 String emailID = "[email protected]";
 String company = "bad";
 String jobTitle = "abcd";

 ArrayList < ContentProviderOperation > ops = new ArrayList < ContentProviderOperation > ();

 ops.add(ContentProviderOperation.newInsert(
 ContactsContract.RawContacts.CONTENT_URI)
     .withValue(ContactsContract.RawContacts.ACCOUNT_TYPE, null)
     .withValue(ContactsContract.RawContacts.ACCOUNT_NAME, null)
     .build());

 //------------------------------------------------------ Names
 if (DisplayName != null) {
     ops.add(ContentProviderOperation.newInsert(
     ContactsContract.Data.CONTENT_URI)
         .withValueBackReference(ContactsContract.Data.RAW_CONTACT_ID, 0)
         .withValue(ContactsContract.Data.MIMETYPE,
     ContactsContract.CommonDataKinds.StructuredName.CONTENT_ITEM_TYPE)
         .withValue(
     ContactsContract.CommonDataKinds.StructuredName.DISPLAY_NAME,
     DisplayName).build());
 }

 //------------------------------------------------------ Mobile Number                     
 if (MobileNumber != null) {
     ops.add(ContentProviderOperation.
     newInsert(ContactsContract.Data.CONTENT_URI)
         .withValueBackReference(ContactsContract.Data.RAW_CONTACT_ID, 0)
         .withValue(ContactsContract.Data.MIMETYPE,
     ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE)
         .withValue(ContactsContract.CommonDataKinds.Phone.NUMBER, MobileNumber)
         .withValue(ContactsContract.CommonDataKinds.Phone.TYPE,
     ContactsContract.CommonDataKinds.Phone.TYPE_MOBILE)
         .build());
 }

 //------------------------------------------------------ Home Numbers
 if (HomeNumber != null) {
     ops.add(ContentProviderOperation.newInsert(ContactsContract.Data.CONTENT_URI)
         .withValueBackReference(ContactsContract.Data.RAW_CONTACT_ID, 0)
         .withValue(ContactsContract.Data.MIMETYPE,
     ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE)
         .withValue(ContactsContract.CommonDataKinds.Phone.NUMBER, HomeNumber)
         .withValue(ContactsContract.CommonDataKinds.Phone.TYPE,
     ContactsContract.CommonDataKinds.Phone.TYPE_HOME)
         .build());
 }

 //------------------------------------------------------ Work Numbers
 if (WorkNumber != null) {
     ops.add(ContentProviderOperation.newInsert(ContactsContract.Data.CONTENT_URI)
         .withValueBackReference(ContactsContract.Data.RAW_CONTACT_ID, 0)
         .withValue(ContactsContract.Data.MIMETYPE,
     ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE)
         .withValue(ContactsContract.CommonDataKinds.Phone.NUMBER, WorkNumber)
         .withValue(ContactsContract.CommonDataKinds.Phone.TYPE,
     ContactsContract.CommonDataKinds.Phone.TYPE_WORK)
         .build());
 }

 //------------------------------------------------------ Email
 if (emailID != null) {
     ops.add(ContentProviderOperation.newInsert(ContactsContract.Data.CONTENT_URI)
         .withValueBackReference(ContactsContract.Data.RAW_CONTACT_ID, 0)
         .withValue(ContactsContract.Data.MIMETYPE,
     ContactsContract.CommonDataKinds.Email.CONTENT_ITEM_TYPE)
         .withValue(ContactsContract.CommonDataKinds.Email.DATA, emailID)
         .withValue(ContactsContract.CommonDataKinds.Email.TYPE, ContactsContract.CommonDataKinds.Email.TYPE_WORK)
         .build());
 }

 //------------------------------------------------------ Organization
 if (!company.equals("") && !jobTitle.equals("")) {
     ops.add(ContentProviderOperation.newInsert(ContactsContract.Data.CONTENT_URI)
         .withValueBackReference(ContactsContract.Data.RAW_CONTACT_ID, 0)
         .withValue(ContactsContract.Data.MIMETYPE,
     ContactsContract.CommonDataKinds.Organization.CONTENT_ITEM_TYPE)
         .withValue(ContactsContract.CommonDataKinds.Organization.COMPANY, company)
         .withValue(ContactsContract.CommonDataKinds.Organization.TYPE, ContactsContract.CommonDataKinds.Organization.TYPE_WORK)
         .withValue(ContactsContract.CommonDataKinds.Organization.TITLE, jobTitle)
         .withValue(ContactsContract.CommonDataKinds.Organization.TYPE, ContactsContract.CommonDataKinds.Organization.TYPE_WORK)
         .build());
 }

 // Asking the Contact provider to create a new contact                 
 try {
     getContentResolver().applyBatch(ContactsContract.AUTHORITY, ops);
 } catch (Exception e) {
     e.printStackTrace();
     Toast.makeText(myContext, "Exception: " + e.getMessage(), Toast.LENGTH_SHORT).show();
 }

Here is the code. Integrate it according to your need. I hope it will help.

Temporarily disable all foreign key constraints

Disable all indexes (including the pk, which will disable all fks), then reenable the pks.

DECLARE @sql AS NVARCHAR(max)=''
select @sql = @sql +
    'ALTER INDEX ALL ON [' + t.[name] + '] DISABLE;'+CHAR(13)
from  
    sys.tables t
where type='u'

select @sql = @sql +
    'ALTER INDEX ' + i.[name] + ' ON [' + t.[name] + '] REBUILD;'+CHAR(13)
from  
    sys.key_constraints i
join
    sys.tables t on i.parent_object_id=t.object_id
where
    i.type='PK'


exec dbo.sp_executesql @sql;
go

[Do your data load]

Then bring everything back to life...

DECLARE @sql AS NVARCHAR(max)=''
select @sql = @sql +
    'ALTER INDEX ALL ON [' + t.[name] + '] REBUILD;'+CHAR(13)
from  
    sys.tables t
where type='u'

exec dbo.sp_executesql @sql;
go

How can I lock the first row and first column of a table when scrolling, possibly using JavaScript and CSS?

You'd have to test it but if you embedded an iframe within your page then used CSS to absolutely position the 1st row & column at 0,0 in the iframe page would that solve your problem?

How does DISTINCT work when using JPA and Hibernate

Depending on the underlying JPQL or Criteria API query type, DISTINCT has two meanings in JPA.

Scalar queries

For scalar queries, which return a scalar projection, like the following query:

List<Integer> publicationYears = entityManager
.createQuery(
    "select distinct year(p.createdOn) " +
    "from Post p " +
    "order by year(p.createdOn)", Integer.class)
.getResultList();

LOGGER.info("Publication years: {}", publicationYears);

The DISTINCT keyword should be passed to the underlying SQL statement because we want the DB engine to filter duplicates prior to returning the result set:

SELECT DISTINCT
    extract(YEAR FROM p.created_on) AS col_0_0_
FROM
    post p
ORDER BY
    extract(YEAR FROM p.created_on)

-- Publication years: [2016, 2018]

Entity queries

For entity queries, DISTINCT has a different meaning.

Without using DISTINCT, a query like the following one:

List<Post> posts = entityManager
.createQuery(
    "select p " +
    "from Post p " +
    "left join fetch p.comments " +
    "where p.title = :title", Post.class)
.setParameter(
    "title", 
    "High-Performance Java Persistence eBook has been released!"
)
.getResultList();

LOGGER.info(
    "Fetched the following Post entity identifiers: {}", 
    posts.stream().map(Post::getId).collect(Collectors.toList())
);

is going to JOIN the post and the post_comment tables like this:

SELECT p.id AS id1_0_0_,
       pc.id AS id1_1_1_,
       p.created_on AS created_2_0_0_,
       p.title AS title3_0_0_,
       pc.post_id AS post_id3_1_1_,
       pc.review AS review2_1_1_,
       pc.post_id AS post_id3_1_0__
FROM   post p
LEFT OUTER JOIN
       post_comment pc ON p.id=pc.post_id
WHERE
       p.title='High-Performance Java Persistence eBook has been released!'

-- Fetched the following Post entity identifiers: [1, 1]

But the parent post records are duplicated in the result set for each associated post_comment row. For this reason, the List of Post entities will contain duplicate Post entity references.

To eliminate the Post entity references, we need to use DISTINCT:

List<Post> posts = entityManager
.createQuery(
    "select distinct p " +
    "from Post p " +
    "left join fetch p.comments " +
    "where p.title = :title", Post.class)
.setParameter(
    "title", 
    "High-Performance Java Persistence eBook has been released!"
)
.getResultList();
 
LOGGER.info(
    "Fetched the following Post entity identifiers: {}", 
    posts.stream().map(Post::getId).collect(Collectors.toList())
);

But then DISTINCT is also passed to the SQL query, and that's not desirable at all:

SELECT DISTINCT
       p.id AS id1_0_0_,
       pc.id AS id1_1_1_,
       p.created_on AS created_2_0_0_,
       p.title AS title3_0_0_,
       pc.post_id AS post_id3_1_1_,
       pc.review AS review2_1_1_,
       pc.post_id AS post_id3_1_0__
FROM   post p
LEFT OUTER JOIN
       post_comment pc ON p.id=pc.post_id
WHERE
       p.title='High-Performance Java Persistence eBook has been released!'
 
-- Fetched the following Post entity identifiers: [1]

By passing DISTINCT to the SQL query, the EXECUTION PLAN is going to execute an extra Sort phase which adds overhead without bringing any value since the parent-child combinations always return unique records because of the child PK column:

Unique  (cost=23.71..23.72 rows=1 width=1068) (actual time=0.131..0.132 rows=2 loops=1)
  ->  Sort  (cost=23.71..23.71 rows=1 width=1068) (actual time=0.131..0.131 rows=2 loops=1)
        Sort Key: p.id, pc.id, p.created_on, pc.post_id, pc.review
        Sort Method: quicksort  Memory: 25kB
        ->  Hash Right Join  (cost=11.76..23.70 rows=1 width=1068) (actual time=0.054..0.058 rows=2 loops=1)
              Hash Cond: (pc.post_id = p.id)
              ->  Seq Scan on post_comment pc  (cost=0.00..11.40 rows=140 width=532) (actual time=0.010..0.010 rows=2 loops=1)
              ->  Hash  (cost=11.75..11.75 rows=1 width=528) (actual time=0.027..0.027 rows=1 loops=1)
                    Buckets: 1024  Batches: 1  Memory Usage: 9kB
                    ->  Seq Scan on post p  (cost=0.00..11.75 rows=1 width=528) (actual time=0.017..0.018 rows=1 loops=1)
                          Filter: ((title)::text = 'High-Performance Java Persistence eBook has been released!'::text)
                          Rows Removed by Filter: 3
Planning time: 0.227 ms
Execution time: 0.179 ms

Entity queries with HINT_PASS_DISTINCT_THROUGH

To eliminate the Sort phase from the execution plan, we need to use the HINT_PASS_DISTINCT_THROUGH JPA query hint:

List<Post> posts = entityManager
.createQuery(
    "select distinct p " +
    "from Post p " +
    "left join fetch p.comments " +
    "where p.title = :title", Post.class)
.setParameter(
    "title", 
    "High-Performance Java Persistence eBook has been released!"
)
.setHint(QueryHints.HINT_PASS_DISTINCT_THROUGH, false)
.getResultList();
 
LOGGER.info(
    "Fetched the following Post entity identifiers: {}", 
    posts.stream().map(Post::getId).collect(Collectors.toList())
);

And now, the SQL query will not contain DISTINCT but Post entity reference duplicates are going to be removed:

SELECT
       p.id AS id1_0_0_,
       pc.id AS id1_1_1_,
       p.created_on AS created_2_0_0_,
       p.title AS title3_0_0_,
       pc.post_id AS post_id3_1_1_,
       pc.review AS review2_1_1_,
       pc.post_id AS post_id3_1_0__
FROM   post p
LEFT OUTER JOIN
       post_comment pc ON p.id=pc.post_id
WHERE
       p.title='High-Performance Java Persistence eBook has been released!'
 
-- Fetched the following Post entity identifiers: [1]

And the Execution Plan is going to confirm that we no longer have an extra Sort phase this time:

Hash Right Join  (cost=11.76..23.70 rows=1 width=1068) (actual time=0.066..0.069 rows=2 loops=1)
  Hash Cond: (pc.post_id = p.id)
  ->  Seq Scan on post_comment pc  (cost=0.00..11.40 rows=140 width=532) (actual time=0.011..0.011 rows=2 loops=1)
  ->  Hash  (cost=11.75..11.75 rows=1 width=528) (actual time=0.041..0.041 rows=1 loops=1)
        Buckets: 1024  Batches: 1  Memory Usage: 9kB
        ->  Seq Scan on post p  (cost=0.00..11.75 rows=1 width=528) (actual time=0.036..0.037 rows=1 loops=1)
              Filter: ((title)::text = 'High-Performance Java Persistence eBook has been released!'::text)
              Rows Removed by Filter: 3
Planning time: 1.184 ms
Execution time: 0.160 ms

How to connect Android app to MySQL database?

Yes you can connect your android app to your PHP to grab results from your database. Use a webservice to connect to your backend script via ASYNC task and http post requests. Check this link for more information Connecting to MySQL

Delete specific line from a text file?

Are you on a Unix operating system?

You can do this with the "sed" stream editor. Read the man page for "sed"

Android, How to create option Menu

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    new MenuInflater(this).inflate(R.menu.folderview_options, menu);
    return (super.onCreateOptionsMenu(menu));
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if (item.getItemId() == R.id.locationListRefreshLocations) {
        Cursor temp = helper.getEmployee(active_employeeId);
        String[] matches = new String[1];
        if (temp.moveToFirst()) {
            matches[0] = helper.getEmployerID(temp);
        }
        temp.close();               
        startRosterReceiveBackgroundTask(matches);
    } else if (item.getItemId()==R.id.locationListPrefs) {
        startActivity(new Intent(this, PreferencesUnlockScreen.class));
        return true;
    }           
    return super.onOptionsItemSelected(item);
}

git push rejected: error: failed to push some refs

What I did to solve the problem was:

git pull origin [branch]
git push origin [branch]

Also make sure that you are pointing to the right branch by running:

git remote set-url origin [url]

Auto expand a textarea using jQuery

Old question but you could do something like this:

html:

<textarea class="text-area" rows="1"></textarea>

jquery:

var baseH; // base scroll height

$('body')
    .one('focus.textarea', '.text-area', function(e) {
        baseH = this.scrollHeight;
    })
    .on('input.textarea', '.text-area', function(e) {
        if(baseH < this.scrollHeight) {
            $(this).height(0).height(this.scrollHeight);
        }
        else {
            $(this).height(0).height(baseH);
        }
    });

This way the auto resize will apply to any textarea with the class "text-area". Also shrinks when text is removed.

jsfiddle:

https://jsfiddle.net/rotaercz/46rhcqyn/

Error With Port 8080 already in use

The solution to this issue is:

Step 1: Stop Tomcat(By service or by .bat/.sh what ever the case may be ).

Step 2: Delete the already configured Apache Tomcat on eclipse.

Step 3: Now reconfigure the apache on the eclipse and start the server using UI as provided by eclipse.

I have the same issue and it has worked.

error: expected primary-expression before ')' token (C)

You should create a variable of the type SelectionneNonSelectionne.

struct SelectionneNonSelectionne var;

After that pass that variable to the function like

characterSelection(screen, var);

The error is caused since you are passing the type name SelectionneNonSelectionne

String: How to replace multiple possible characters with a single character?

Java - Create a new String instance with specified length and filled with specific character. Best solution?

public static String fillString(int count,char c) {
    StringBuilder sb = new StringBuilder( count );
    for( int i=0; i<count; i++ ) {
        sb.append( c ); 
    }
    return sb.toString();
}

What is wrong?

How to create a library project in Android Studio and an application project that uses the library project

For Intellij IDEA (and Android Studio) each library is a Module. Think of a Module in Android Studio as an equivalent to project in Eclipse. Project in Android Studio is a collection of modules. Modules can be runnable applications or library modules.

So, in order to add a new android library project to you need to create a module of type "Android library". Then add this library module to the dependency list of your main module (Application module).

How to approach a "Got minus one from a read call" error when connecting to an Amazon RDS Oracle instance

The immediate cause of the problem is that the JDBC driver has attempted to read from a network Socket that has been closed by "the other end".

This could be due to a few things:

If the remote server has been configured (e.g. in the "SQLNET.ora" file) to not accept connections from your IP.
If the JDBC url is incorrect, you could be attempting to connect to something that isn't a database.
If there are too many open connections to the database service, it could refuse new connections.

Given the symptoms, I think the "too many connections" scenario is the most likely. That suggests that your application is leaking connections; i.e. creating connections and then failing to (always) close them.

Scroll Element into View with Selenium

Selenium can scroll to some element in the scrollbar automatically for some simple UI, but for lazy-load UI, scrollToElement is still needed.

This is my implementation in Java with JavascriptExecutor. You can find more details in Satix source code: http://www.binpress.com/app/satix-seleniumbased-automation-testing-in-xml/1958

public static void perform(WebDriver driver, String Element, String ElementBy, By by) throws Exception {
 try {
  //long start_time = System.currentTimeMillis();           
  StringBuilder js = new StringBuilder();
  String browser = "firefox";

  if (ElementBy.equals("id")) {
   js.append("var b = document.getElementById(\"" +
    Element + "\");");
  } else if (ElementBy.equals("xpath")) {
   if (!"IE".equals(browser)) {
    js.append("var b = document.evaluate(\"" +
     Element +
     "\", document, null, XPathResult.ANY_TYPE, null).iterateNext();");
   } else {
    throw new Exception("Action error: xpath is not supported in scrollToElement Action in IE");
   }
  } else if (ElementBy.equals("cssSelector")) {
   js.append("var b = document.querySelector(\"" +
    Element + "\");");
  } else {
   throw new Exception("Scroll Action error");
  }

  String getScrollHeightScript = js.toString() + "var o = new Array(); o.push(b.scrollHeight); return o;";

  js.append("b.scrollTop = b.scrollTop + b.clientHeight;");
  js.append("var tmp = b.scrollTop + b.clientHeight;");
  js.append("var o = new Array(); o.push(tmp); return o;");

  int tries = 1;
  String scrollTop = "0";
  while (tries > 0) {
   try {
    String scrollHeight = ((JavascriptExecutor) driver).executeScript(getScrollHeightScript).toString();
    if (scrollTop.equals(scrollHeight)) {
     break;
    } else if (driver.findElement(by).isDisplayed()) {
     break;
    }
    Object o = ((JavascriptExecutor) driver).executeScript(js.toString());
    scrollTop = o.toString();
    Thread.sleep(interval);
    tries++;
   } catch (Exception e) {
    throw new Exception("Action error:" +
     " javascript execute error : " + e.getMessage() + ", javascript : " + js.toString());
   }
  }

 } catch (Exception e) {
  try {
   ScreenshotCapturerUtil.saveScreenShot(driver, CLASSNAME);
  } catch (IOException e1) {
   throw new Exception("Save screenshot error!", e1);
  }
  throw e;
 }
}

Converting integer to digit list

If you have a string like this: '123456' and you want a list of integers like this: [1,2,3,4,5,6], use this:

>>>s = '123456'    
>>>list1 = [int(i) for i in list(s)]
>>>print(list1)

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

or if you want a list of strings like this: ['1','2','3','4','5','6'], use this:

>>>s = '123456'    
>>>list1 = list(s)
>>>print(list1)

['1','2','3','4','5','6']

How to find char in string and get all the indexes?

As the rule of thumb, NumPy arrays often outperform other solutions while working with POD, Plain Old Data. A string is an example of POD and a character too. To find all the indices of only one char in a string, NumPy ndarrays may be the fastest way:

def find1(str, ch):
  # 0.100 seconds for 1MB str 
  npbuf = np.frombuffer(str, dtype=np.uint8) # Reinterpret str as a char buffer
  return np.where(npbuf == ord(ch))          # Find indices with numpy

def find2(str, ch):
  # 0.920 seconds for 1MB str 
  return [i for i, c in enumerate(str) if c == ch] # Find indices with python

Making a UITableView scroll when text field is selected

Look at my version :)

    - (void)keyboardWasShown:(NSNotification *)aNotification
{
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    CGRect bkgndRect = cellSelected.superview.frame;
    bkgndRect.size.height += kbSize.height;
    [cellSelected.superview setFrame:bkgndRect];
    [tableView setContentOffset:CGPointMake(0.0, cellSelected.frame.origin.y-kbSize.height) animated:YES];
}


- (void)keyboardWasHidden:(NSNotification *)aNotification
{
    [tableView setContentOffset:CGPointMake(0.0, 0.0) animated:YES];
}

How to: Install Plugin in Android Studio

File-> Settings->Under IDE Settings click on Plugins. Now in right side window Click on Browse repositories and there you can find the plugins. Select which one you want and click on install

use jQuery's find() on JSON object

This works for me on [{"id":"data"},{"id":"data"}]

function getObjects(obj, key, val) 
{
    var newObj = false; 
    $.each(obj, function()
    {
        var testObject = this; 
        $.each(testObject, function(k,v)
        {
            //alert(k);
            if(val == v && k == key)
            {
                newObj = testObject;
            }
        });
    });

    return newObj;
}

Using SELECT result in another SELECT

NewScores is an alias to Scores table - it looks like you can combine the queries as follows:

SELECT 
    ROW_NUMBER() OVER( ORDER BY NETT) AS Rank, 
    Name, 
    FlagImg, 
    Nett, 
    Rounds 
FROM (
    SELECT 
        Members.FirstName + ' ' + Members.LastName AS Name, 
        CASE 
            WHEN MenuCountry.ImgURL IS NULL THEN 
                '~/images/flags/ismygolf.png' 
            ELSE 
                MenuCountry.ImgURL 
        END AS FlagImg, 
        AVG(CAST(NewScores.NetScore AS DECIMAL(18, 4))) AS Nett, 
        COUNT(Score.ScoreID) AS Rounds 
    FROM 
        Members 
        INNER JOIN 
        Score NewScores
            ON Members.MemberID = NewScores.MemberID 
        LEFT OUTER JOIN MenuCountry 
            ON Members.Country = MenuCountry.ID 
    WHERE 
        Members.Status = 1 
        AND NewScores.InsertedDate >= DATEADD(mm, -3, GETDATE())
    GROUP BY 
        Members.FirstName + ' ' + Members.LastName, 
        MenuCountry.ImgURL
    ) AS Dertbl 
ORDER BY;

How to cache Google map tiles for offline usage?

If you are trying to cache the tiles that Google serves, that may be a violation of Google's Terms of Service (unless, under certain circumstances, if you've purchased their enterprise Maps API Premier). That's why gmapcatcher has it crossed off their list. See http://code.google.com/p/gmapcatcher/issues/detail?id=210.

At the gmapcatcher URL above, you will also find a shell script that can download tiles (or so its author says).

There are also other projects that try to make Google Maps available offline:

http://code.google.com/p/ogmaps/

http://code.google.com/p/gmapoffline/

Lastly, if Google Earth can meet your needs, then you can use that. Offline usage of Google Earth requires a Google Earth Enterprise license according to http://www.google.com/permissions/geoguidelines.html.

Note that the preceding page also says: "You may not scrape or otherwise export Content from Google Maps or Earth or save it for offline use." So if you try to cache tiles, that will almost certainly be considered (by Google, anyway) a violation of the Terms of Service.

u'\ufeff' in Python string

The content you're scraping is encoded in unicode rather than ascii text, and you're getting a character that doesn't convert to ascii. The right 'translation' depends on what the original web page thought it was. Python's unicode page gives the background on how it works.

Are you trying to print the result or stick it in a file? The error suggests it's writing the data that's causing the problem, not reading it. This question is a good place to look for the fixes.

Simple C example of doing an HTTP POST and consuming the response

A message has a header part and a message body separated by a blank line. The blank line is ALWAYS needed even if there is no message body. The header starts with a command and has additional lines of key value pairs separated by a colon and a space. If there is a message body, it can be anything you want it to be.

Lines in the header and the blank line at the end of the header must end with a carraige return and linefeed pair (see HTTP header line break style) so that's why those lines have \r\n at the end.

A URL has the form of http://host:port/path?query_string

There are two main ways of submitting a request to a website:

GET: The query string is optional but, if specified, must be reasonably short. Because of this the header could just be the GET command and nothing else. A sample message could be:
```
GET /path?query_string HTTP/1.0\r\n
\r\n
```
POST: What would normally be in the query string is in the body of the message instead. Because of this the header needs to include the Content-Type: and Content-Length: attributes as well as the POST command. A sample message could be:
```
POST /path HTTP/1.0\r\n
Content-Type: text/plain\r\n
Content-Length: 12\r\n
\r\n
query_string
```

So, to answer your question: if the URL you are interested in POSTing to is http://api.somesite.com/apikey=ARG1&command=ARG2 then there is no body or query string and, consequently, no reason to POST because there is nothing to put in the body of the message and so nothing to put in the Content-Type: and Content-Length:

I guess you could POST if you really wanted to. In that case your message would look like:

POST /apikey=ARG1&command=ARG2 HTTP/1.0\r\n
\r\n

So to send the message the C program needs to:

create a socket
lookup the IP address
open the socket
send the request
wait for the response
close the socket

The send and receive calls won't necessarily send/receive ALL the data you give them - they will return the number of bytes actually sent/received. It is up to you to call them in a loop and send/receive the remainder of the message.

What I did not do in this sample is any sort of real error checking - when something fails I just exit the program. Let me know if it works for you:

#include <stdio.h> /* printf, sprintf */
#include <stdlib.h> /* exit */
#include <unistd.h> /* read, write, close */
#include <string.h> /* memcpy, memset */
#include <sys/socket.h> /* socket, connect */
#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
#include <netdb.h> /* struct hostent, gethostbyname */

void error(const char *msg) { perror(msg); exit(0); }

int main(int argc,char *argv[])
{
    /* first what are we going to send and where are we going to send it? */
    int portno =        80;
    char *host =        "api.somesite.com";
    char *message_fmt = "POST /apikey=%s&command=%s HTTP/1.0\r\n\r\n";

    struct hostent *server;
    struct sockaddr_in serv_addr;
    int sockfd, bytes, sent, received, total;
    char message[1024],response[4096];

    if (argc < 3) { puts("Parameters: <apikey> <command>"); exit(0); }

    /* fill in the parameters */
    sprintf(message,message_fmt,argv[1],argv[2]);
    printf("Request:\n%s\n",message);

    /* create the socket */
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) error("ERROR opening socket");

    /* lookup the ip address */
    server = gethostbyname(host);
    if (server == NULL) error("ERROR, no such host");

    /* fill in the structure */
    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(portno);
    memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);

    /* connect the socket */
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");

    /* send the request */
    total = strlen(message);
    sent = 0;
    do {
        bytes = write(sockfd,message+sent,total-sent);
        if (bytes < 0)
            error("ERROR writing message to socket");
        if (bytes == 0)
            break;
        sent+=bytes;
    } while (sent < total);

    /* receive the response */
    memset(response,0,sizeof(response));
    total = sizeof(response)-1;
    received = 0;
    do {
        bytes = read(sockfd,response+received,total-received);
        if (bytes < 0)
            error("ERROR reading response from socket");
        if (bytes == 0)
            break;
        received+=bytes;
    } while (received < total);

    if (received == total)
        error("ERROR storing complete response from socket");

    /* close the socket */
    close(sockfd);

    /* process response */
    printf("Response:\n%s\n",response);

    return 0;
}

Like the other answer pointed out, 4096 bytes is not a very big response. I picked that number at random assuming that the response to your request would be short. If it can be big you have two choices:

read the Content-Length: header from the response and then dynamically allocate enough memory to hold the whole response.
write the response to a file as the pieces arrive

Additional information to answer the question asked in the comments:

What if you want to POST data in the body of the message? Then you do need to include the Content-Type: and Content-Length: headers. The Content-Length: is the actual length of everything after the blank line that separates the header from the body.

Here is a sample that takes the following command line arguments:

host
port
command (GET or POST)
path (not including the query data)
query data (put into the query string for GET and into the body for POST)
list of headers (Content-Length: is automatic if using POST)

So, for the original question you would run:

a.out api.somesite.com 80 GET "/apikey=ARG1&command=ARG2"

And for the question asked in the comments you would run:

a.out api.somesite.com 80 POST / "name=ARG1&value=ARG2" "Content-Type: application/x-www-form-urlencoded"

Here is the code:

#include <stdio.h> /* printf, sprintf */
#include <stdlib.h> /* exit, atoi, malloc, free */
#include <unistd.h> /* read, write, close */
#include <string.h> /* memcpy, memset */
#include <sys/socket.h> /* socket, connect */
#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
#include <netdb.h> /* struct hostent, gethostbyname */

void error(const char *msg) { perror(msg); exit(0); }

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

    /* first where are we going to send it? */
    int portno = atoi(argv[2])>0?atoi(argv[2]):80;
    char *host = strlen(argv[1])>0?argv[1]:"localhost";

    struct hostent *server;
    struct sockaddr_in serv_addr;
    int sockfd, bytes, sent, received, total, message_size;
    char *message, response[4096];

    if (argc < 5) { puts("Parameters: <host> <port> <method> <path> [<data> [<headers>]]"); exit(0); }

    /* How big is the message? */
    message_size=0;
    if(!strcmp(argv[3],"GET"))
    {
        message_size+=strlen("%s %s%s%s HTTP/1.0\r\n");        /* method         */
        message_size+=strlen(argv[3]);                         /* path           */
        message_size+=strlen(argv[4]);                         /* headers        */
        if(argc>5)
            message_size+=strlen(argv[5]);                     /* query string   */
        for(i=6;i<argc;i++)                                    /* headers        */
            message_size+=strlen(argv[i])+strlen("\r\n");
        message_size+=strlen("\r\n");                          /* blank line     */
    }
    else
    {
        message_size+=strlen("%s %s HTTP/1.0\r\n");
        message_size+=strlen(argv[3]);                         /* method         */
        message_size+=strlen(argv[4]);                         /* path           */
        for(i=6;i<argc;i++)                                    /* headers        */
            message_size+=strlen(argv[i])+strlen("\r\n");
        if(argc>5)
            message_size+=strlen("Content-Length: %d\r\n")+10; /* content length */
        message_size+=strlen("\r\n");                          /* blank line     */
        if(argc>5)
            message_size+=strlen(argv[5]);                     /* body           */
    }

    /* allocate space for the message */
    message=malloc(message_size);

    /* fill in the parameters */
    if(!strcmp(argv[3],"GET"))
    {
        if(argc>5)
            sprintf(message,"%s %s%s%s HTTP/1.0\r\n",
                strlen(argv[3])>0?argv[3]:"GET",               /* method         */
                strlen(argv[4])>0?argv[4]:"/",                 /* path           */
                strlen(argv[5])>0?"?":"",                      /* ?              */
                strlen(argv[5])>0?argv[5]:"");                 /* query string   */
        else
            sprintf(message,"%s %s HTTP/1.0\r\n",
                strlen(argv[3])>0?argv[3]:"GET",               /* method         */
                strlen(argv[4])>0?argv[4]:"/");                /* path           */
        for(i=6;i<argc;i++)                                    /* headers        */
            {strcat(message,argv[i]);strcat(message,"\r\n");}
        strcat(message,"\r\n");                                /* blank line     */
    }
    else
    {
        sprintf(message,"%s %s HTTP/1.0\r\n",
            strlen(argv[3])>0?argv[3]:"POST",                  /* method         */
            strlen(argv[4])>0?argv[4]:"/");                    /* path           */
        for(i=6;i<argc;i++)                                    /* headers        */
            {strcat(message,argv[i]);strcat(message,"\r\n");}
        if(argc>5)
            sprintf(message+strlen(message),"Content-Length: %d\r\n",strlen(argv[5]));
        strcat(message,"\r\n");                                /* blank line     */
        if(argc>5)
            strcat(message,argv[5]);                           /* body           */
    }

    /* What are we going to send? */
    printf("Request:\n%s\n",message);

    /* create the socket */
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) error("ERROR opening socket");

    /* lookup the ip address */
    server = gethostbyname(host);
    if (server == NULL) error("ERROR, no such host");

    /* fill in the structure */
    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(portno);
    memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);

    /* connect the socket */
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");

    /* send the request */
    total = strlen(message);
    sent = 0;
    do {
        bytes = write(sockfd,message+sent,total-sent);
        if (bytes < 0)
            error("ERROR writing message to socket");
        if (bytes == 0)
            break;
        sent+=bytes;
    } while (sent < total);

    /* receive the response */
    memset(response,0,sizeof(response));
    total = sizeof(response)-1;
    received = 0;
    do {
        bytes = read(sockfd,response+received,total-received);
        if (bytes < 0)
            error("ERROR reading response from socket");
        if (bytes == 0)
            break;
        received+=bytes;
    } while (received < total);

    if (received == total)
        error("ERROR storing complete response from socket");

    /* close the socket */
    close(sockfd);

    /* process response */
    printf("Response:\n%s\n",response);

    free(message);
    return 0;
}

Laravel, sync() - how to sync an array and also pass additional pivot fields?

Attaching / Detaching

Eloquent also provides a few additional helper methods to make working with related models more convenient. For example, let's imagine a user can have many roles and a role can have many users. To attach a role to a user by inserting a record in the intermediate table that joins the models, use the attach method:

$user = App\User::find(1);

$user->roles()->attach($roleId);

When attaching a relationship to a model, you may also pass an array of additional data to be inserted into the intermediate table:

$user->roles()->attach($roleId, ['expires' => $expires]);

You can also use Sync if you want to remove old roles and only keep the new ones you are attaching now

$user->roles()->sync([1 => ['expires' => $expires], 2 => ['expires' => $expires]);

The default behaviour can be changed by passing a 'false' as a second argument. This will attach the roles with ids 1,2,3 without affecting the existing roles.

In this mode sync behaves similar to the attach method.

$user->roles()->sync([1 => ['expires' => $expires], 2 => ['expires' => $expires], false);

Reference: https://laravel.com/docs/5.4/eloquent-relationships

Best way to restrict a text field to numbers only?

In order to block anything but numbers from being input into a text field but still allowing for other buttons to work (such as delete, shift, tab, etc.) look at a reference of the Javascript key codes; anything from 65 on up (to 222) can be blocked.

Using Jquery and Javascript, that would look like:

$('#textFieldId').keydown(function(event) {
    if ( event.keyCode > 64 ) {
        event.preventDefault();
    }
});

The key codes will be the same in Javascript whether or not Jquery is used.

How can I comment a single line in XML?

As others have said, there is no way to do a single line comment legally in XML that comments out multiple lines, but, there are ways to make commenting out segments of XML easier.

Looking at the example below, if you add '>' to line one, the XmlTag will be uncommented. Remove the '>' and it's commented out again. This is the simplest way that I've seen to quickly comment/uncomment XML without breaking things.

<!-- --
<XmlTag variable="0" />
<!-- -->

The added benefit is that you only manipulate the top comment, and the bottom comment can just sit there forever. This breaks compatibility with SGML and some XML parsers will barf on it. So long as this isn't a permanent fixture in your XML, and your parsers accept it, it's not really a problem.

Stack Overflow's and Notepad++'s syntax highlighter treat it like a multi-line comment, C++'s Boost library treats it as a multi-line comment, and the only parser I've found so far that breaks is the one in .NET, specifically C#. So, be sure to first test that your tools, IDE, libraries, language, etc. accept it before using it.

If you care about SGML compatibility, simply use this instead:

<!-- -
<XmlTag variable="0" />
<!- -->

Add '->' to the top comment and a '-' to the bottom comment. The downside is having to edit the bottom comment each time, which would probably make it easier to just type in  at the bottom each time.

I also want to mention that other commenters recommend using an XML editor that allows you to right-click and comment/uncomment blocks of XML, which is probably preferable over fancy find/replace tricks (it would also make for a good answer in itself, but I've never used such tools. I just want to make sure the information isn't lost over time). I've personally never had to deal with XML enough to justify having an editor fancier than Notepad++, so this is totally up to you.

Convert string to buffer Node

Note: Just reposting John Zwinck's comment as answer.

One issue might be that you are using a older version of Node (for the moment, I cannot upgrade, codebase struck with v4.3.1). Simple solution here is, using the deprecated way:

new Buffer(bufferStr)

Note #2: This is for people struck in older version, for whom Buffer.from does not work

how to make a html iframe 100% width and height?

Answering this just in case if someone else like me stumbles upon this post among many that advise use of JavaScripts for changing iframe height to 100%.

I strongly recommend that you see and try this option specified at How do you give iframe 100% height before resorting to a JavaScript based option. The referenced solution works perfectly for me in all of the testing I have done so far. Hope this helps someone.

JavaScript to get rows count of a HTML table

If the table has an ID:

const tableObject = document.getElementById(tableId);
const rowCount = tableObject[1].childElementCount;

If the table has a Class:

const tableObject = document.getElementsByClassName(tableClass);
const rowCount = tableObject[1].childElementCount;

If the table has a Name:

const tableObject = document.getElementsByTagName('table');
const rowCount = tableObject[1].childElementCount;

Note: index 1 represents <tbody> tag

Faking an RS232 Serial Port

I know this is an old post, but in case someone else happens upon this question, one ~~good~~ option is Virtual Serial Port Emulator (VSPE) from Eterlogic It provides an API for creating kernel mode virtual comport devices, i.e. connectors, mappers, splitters etc.
However, some of the advertised capabilities were really not capabilities at all.

EDIT
A much better choice, Eltima. This product is fully baked. Good developer tech support. The product did all it claimed to do. Product options include both desktop applications, as well as software development kits with APIs.

Neither of these products are open source, or free. However, as other posts here have pointed out, there are other options. Here is a list of various serial utilities:

com0com (current)
com0com - With Signed Driver (old version)
Yet another place for com0com with Signed Driver (Pete's Blog)
Tactical Software
Termite
COM Port Serial Emulator
Kermit (obsolete, but still downloadable)
HWVSP3
HHD Software (free edition)

Breaking up long strings on multiple lines in Ruby without stripping newlines

I modified Zack's answer since I wanted spaces and interpolation but not newlines and used:

%W[
  It's a nice day "#{name}"
  for a walk!
].join(' ')

where name = 'fred' this produces It's a nice day "fred" for a walk!

How to generate a random number in C++?

The most fundamental problem of your test application is that you call srand once and then call rand one time and exit.

The whole point of srand function is to initialize the sequence of pseudo-random numbers with a random seed.

It means that if you pass the same value to srand in two different applications (with the same srand/rand implementation) then you will get exactly the same sequence of rand() values read after that in both applications.

However in your example application pseudo-random sequence consists only of one element - the first element of a pseudo-random sequence generated from seed equal to current time of 1 sec precision. What do you expect to see on output then?

Obviously when you happen to run application on the same second - you use the same seed value - thus your result is the same of course (as Martin York already mentioned in a comment to the question).

Actually you should call srand(seed) one time and then call rand() many times and analyze that sequence - it should look random.

EDIT:

Oh I get it. Apparently verbal description is not enough (maybe language barrier or something... :) ).

OK. Old-fashioned C code example based on the same srand()/rand()/time() functions that was used in the question:

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

int main(void)
{
    unsigned long j;
    srand( (unsigned)time(NULL) );

    for( j = 0; j < 100500; ++j )
    {
        int n;

        /* skip rand() readings that would make n%6 non-uniformly distributed
          (assuming rand() itself is uniformly distributed from 0 to RAND_MAX) */
        while( ( n = rand() ) > RAND_MAX - (RAND_MAX-5)%6 )
        { /* bad value retrieved so get next one */ }

        printf( "%d,\t%d\n", n, n % 6 + 1 );
    }

    return 0;
}

^^^ THAT sequence from a single run of the program is supposed to look random.

Please NOTE that I don't recommend to use rand/srand functions in production for the reasons explained below and I absolutely don't recommend to use function time as a random seed for the reasons that IMO already should be quite obvious. Those are fine for educational purposes and to illustrate the point sometimes but for any serious use they are mostly useless.

EDIT2:

When using C or C++ standard library it is important to understand that as of now there is not a single standard function or class producing actually random data definitively (guaranteed by the standard). The only standard tool that approaches this problem is std::random_device that unfortunately still does not provide guarantees of actual randomness.

Depending on the nature of application you should first decide if you really need truly random (unpredictable) data. Notable case when you do most certainly need true randomness is information security - e.g. generating symmetric keys, asymmetric private keys, salt values, security tokens, etc.

However security-grade random numbers is a separate industry worth a separate article.

In most cases Pseudo-Random Number Generator is sufficient - e.g. for scientific simulations or games. In some cases consistently defined pseudo-random sequence is even required - e.g. in games you may choose to generate exactly same maps in runtime to avoid storing lots of data.

The original question and reoccurring multitude of identical/similar questions (and even many misguided "answers" to them) indicate that first and foremost it is important to distinguish random numbers from pseudo-random numbers AND to understand what is pseudo-random number sequence in the first place AND to realize that pseudo-random number generators are NOT used the same way you could use true random number generators.

Intuitively when you request random number - the result returned shouldn't depend on previously returned values and shouldn't depend if anyone requested anything before and shouldn't depend in what moment and by what process and on what computer and from what generator and in what galaxy it was requested. That is what word "random" means after all - being unpredictable and independent of anything - otherwise it is not random anymore, right? With this intuition it is only natural to search the web for some magic spells to cast to get such random number in any possible context.

^^^ THAT kind of intuitive expectations IS VERY WRONG and harmful in all cases involving Pseudo-Random Number Generators - despite being reasonable for true random numbers.

While the meaningful notion of "random number" exists (kind of) - there is no such thing as "pseudo-random number". A Pseudo-Random Number Generator actually produces pseudo-random number sequence.

Pseudo-random sequence is in fact always deterministic (predetermined by its algorithm and initial parameters) i.e. there is actually nothing random about it.

When experts talk about quality of PRNG they actually talk about statistical properties of the generated sequence (and its notable sub-sequences). For example if you combine two high quality PRNGs by using them both in turns - you may produce bad resulting sequence - despite them generating good sequences each separately (those two good sequences may simply correlate to each other and thus combine badly).

Specifically rand()/srand(s) pair of functions provide a singular per-process non-thread-safe(!) pseudo-random number sequence generated with implementation-defined algorithm. Function rand() produces values in range [0, RAND_MAX].

Quote from C11 standard (ISO/IEC 9899:2011):

The srand function uses the argument as a seed for a new sequence of pseudo-random numbers to be returned by subsequent calls to rand. If srand is then called with the same seed value, the sequence of pseudo-random numbers shall be repeated. If rand is called before any calls to srand have been made, the same sequence shall be generated as when srand is first called with a seed value of 1.

Many people reasonably expect that rand() would produce a sequence of semi-independent uniformly distributed numbers in range 0 to RAND_MAX. Well it most certainly should (otherwise it's useless) but unfortunately not only standard doesn't require that - there is even explicit disclaimer that states "there is no guarantees as to the quality of the random sequence produced". In some historical cases rand/srand implementation was of very bad quality indeed. Even though in modern implementations it is most likely good enough - but the trust is broken and not easy to recover. Besides its non-thread-safe nature makes its safe usage in multi-threaded applications tricky and limited (still possible - you may just use them from one dedicated thread).

New class template std::mersenne_twister_engine<> (and its convenience typedefs - std::mt19937/std::mt19937_64 with good template parameters combination) provides per-object pseudo-random number generator defined in C++11 standard. With the same template parameters and the same initialization parameters different objects will generate exactly the same per-object output sequence on any computer in any application built with C++11 compliant standard library. The advantage of this class is its predictably high quality output sequence and full consistency across implementations.

Also there are more PRNG engines defined in C++11 standard - std::linear_congruential_engine<> (historically used as fair quality srand/rand algorithm in some C standard library implementations) and std::subtract_with_carry_engine<>. They also generate fully defined parameter-dependent per-object output sequences.

Modern day C++11 example replacement for the obsolete C code above:

#include <iostream>
#include <chrono>
#include <random>

int main()
{
    std::random_device rd;
    // seed value is designed specifically to make initialization
    // parameters of std::mt19937 (instance of std::mersenne_twister_engine<>)
    // different across executions of application
    std::mt19937::result_type seed = rd() ^ (
            (std::mt19937::result_type)
            std::chrono::duration_cast<std::chrono::seconds>(
                std::chrono::system_clock::now().time_since_epoch()
                ).count() +
            (std::mt19937::result_type)
            std::chrono::duration_cast<std::chrono::microseconds>(
                std::chrono::high_resolution_clock::now().time_since_epoch()
                ).count() );

    std::mt19937 gen(seed);

    for( unsigned long j = 0; j < 100500; ++j )
    /* ^^^Yes. Generating single pseudo-random number makes no sense
       even if you use std::mersenne_twister_engine instead of rand()
       and even when your seed quality is much better than time(NULL) */    
    {
        std::mt19937::result_type n;
        // reject readings that would make n%6 non-uniformly distributed
        while( ( n = gen() ) > std::mt19937::max() -
                                    ( std::mt19937::max() - 5 )%6 )
        { /* bad value retrieved so get next one */ }

        std::cout << n << '\t' << n % 6 + 1 << '\n';
    }

    return 0;
}

The version of previous code that uses std::uniform_int_distribution<>

#include <iostream>
#include <chrono>
#include <random>

int main()
{
    std::random_device rd;
    std::mt19937::result_type seed = rd() ^ (
            (std::mt19937::result_type)
            std::chrono::duration_cast<std::chrono::seconds>(
                std::chrono::system_clock::now().time_since_epoch()
                ).count() +
            (std::mt19937::result_type)
            std::chrono::duration_cast<std::chrono::microseconds>(
                std::chrono::high_resolution_clock::now().time_since_epoch()
                ).count() );

    std::mt19937 gen(seed);
    std::uniform_int_distribution<unsigned> distrib(1, 6);

    for( unsigned long j = 0; j < 100500; ++j )
    {
        std::cout << distrib(gen) << ' ';
    }

    std::cout << '\n';
    return 0;
}

JavaScript: Parsing a string Boolean value?

You can add this code:

function parseBool(str) {

  if (str.length == null) {
    return str == 1 ? true : false;
  } else {
    return str == "true" ? true : false;
  }

}

Works like this:

parseBool(1) //true
parseBool(0) //false
parseBool("true") //true
parseBool("false") //false

What is %2C in a URL?

In Firefox there is Ctrl+Shift+K for the Web console, then you type

;decodeURIComponent("%2c")

mind the semicolon in the beginning
if you Copy&Paste, you should first enable it (the console will warn you)

and you get the answer:

","

How do I specify different layouts for portrait and landscape orientations?

Right click res folder,
New -> Android Resource File
in Available qualifiers, select Orientation,
add to Chosen qualifier
in Screen orientation, select Landscape
Press OK

~~Using Android Studio 3.4.1, it no longer creates layout-land folder. It will create a folder and put two layout files together.~~

How to make circular background using css?

Keep it simple:

.circle
  {
    border-radius: 50%;
    width: 200px;
    height: 200px; 
  }

Width and height can be anything, as long as they're equal

Uploading into folder in FTP?

The folder is part of the URL you set when you create request: "ftp://www.contoso.com/test.htm". If you use "ftp://www.contoso.com/wibble/test.htm" then the file will be uploaded to a folder named wibble.

You may need to first use a request with Method = WebRequestMethods.Ftp.MakeDirectory to make the wibble folder if it doesn't already exist.

Close a div by clicking outside

 //for closeing the popover when user click outside it will close all popover 
 var hidePopover = function(element) {
        var elementScope = angular.element($(element).siblings('.popover')).scope().$parent;
        elementScope.isOpen = false;
        elementScope.$apply();
        //Remove the popover element from the DOM
        $(element).siblings('.popover').remove();
    };
 $(document).ready(function(){
 $('body').on('click', function (e) {
       $("a").each(function () {
                    //Only do this for all popovers other than the current one that cause this event
           if (!($(this).is(e.target) || $(this).has(e.target).length > 0) 
                && $(this).siblings('.popover').length !== 0 && $(this).siblings('.popover').has(e.target).length === 0)                  
                    {
                         hidePopover(this);
                    }
        });
    });
 });

String, StringBuffer, and StringBuilder

----------------------------------------------------------------------------------
                  String                    StringBuffer         StringBuilder
----------------------------------------------------------------------------------                 
Storage Area | Constant String Pool         Heap                   Heap 
Modifiable   |  No (immutable)              Yes( mutable )         Yes( mutable )
Thread Safe  |      Yes                     Yes                     No
 Performance |     Fast                 Very slow                  Fast
----------------------------------------------------------------------------------

PHP7 : install ext-dom issue

For CentOS, RHEL, Fedora:

$ yum search php-xml
============================================================================================================ N/S matched: php-xml ============================================================================================================
php-xml.x86_64 : A module for PHP applications which use XML
php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php-xmlseclibs.noarch : PHP library for XML Security
php54-php-xml.x86_64 : A module for PHP applications which use XML
php54-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php55-php-xml.x86_64 : A module for PHP applications which use XML
php55-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php56-php-xml.x86_64 : A module for PHP applications which use XML
php56-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php70-php-xml.x86_64 : A module for PHP applications which use XML
php70-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php71-php-xml.x86_64 : A module for PHP applications which use XML
php71-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php72-php-xml.x86_64 : A module for PHP applications which use XML
php72-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php73-php-xml.x86_64 : A module for PHP applications which use XML
php73-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol

Then select the php-xml version matching your php version:

# php -v
PHP 7.2.11 (cli) (built: Oct 10 2018 10:00:29) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

# sudo yum install -y php72-php-xml.x86_64

Swift - Remove " character from string

You've instantiated text2 as an Optional (e.g. var text2: String?). This is why you receive Optional("5") in your string. take away the ? and replace with:

var text2: String = ""

JPA Hibernate Persistence exception [PersistenceUnit: default] Unable to build Hibernate SessionFactory

I found some issue about that kind of error

Database username or password not match in the mysql or other other database. Please set application.properties like this

  
# ===============================
# = DATA SOURCE
# ===============================
# Set here configurations for the database connection
# Connection url for the database please let me know "[email protected]"
spring.datasource.url = jdbc:mysql://localhost:3306/bookstoreapiabc
# Username and secret
spring.datasource.username = root
spring.datasource.password =
# Keep the connection alive if idle for a long time (needed in production)
spring.datasource.testWhileIdle = true
spring.datasource.validationQuery = SELECT 1
# ===============================
# = JPA / HIBERNATE
# ===============================
# Use spring.jpa.properties.* for Hibernate native properties (the prefix is
# stripped before adding them to the entity manager).
# Show or not log for each sql query
spring.jpa.show-sql = true
# Hibernate ddl auto (create, create-drop, update): with "update" the database
# schema will be automatically updated accordingly to java entities found in
# the project
spring.jpa.hibernate.ddl-auto = update
# Allows Hibernate to generate SQL optimized for a particular DBMS
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect

Issue no 2.

Your local server has two database server and those database server conflict. this conflict like this mysql server & xampp or lampp or wamp server. Please one of the database like mysql server because xampp or lampp server automatically install mysql server on this machine

How can I create a war file of my project in NetBeans?

It is in the dist folder inside of the project, but only if "Compress WAR File" in the project settings dialog ( build / packaging) ist checked. Before I checked this checkbox there was no dist folder.

Error: TypeError: $(...).dialog is not a function

Change jQueryUI to version 1.11.4 and make sure jQuery is not added twice.

How to capture multiple repeated groups?

Sorry, not Swift, just a proof of concept in the closest language at hand.

// JavaScript POC. Output:
// Matches:  ["GOODBYE","CRUEL","WORLD","IM","LEAVING","U","TODAY"]

let str = `GOODBYE,CRUEL,WORLD,IM,LEAVING,U,TODAY`
let matches = [];

function recurse(str, matches) {
    let regex = /^((,?([A-Z]+))+)$/gm
    let m
    while ((m = regex.exec(str)) !== null) {
        matches.unshift(m[3])
        return str.replace(m[2], '')
    }
    return "bzzt!"
}

while ((str = recurse(str, matches)) != "bzzt!") ;
console.log("Matches: ", JSON.stringify(matches))

Note: If you were really going to use this, you would use the position of the match as given by the regex match function, not a string replace.

Using regular expression in css?

I usually use * when I want to get all the strings that contain the wanted characters.

* used in regex, replaces all characters.

Used in SASS or CSS would be something like [id*="s"] and it will get all DOM elements with id "s......".

/* add red color to all div with id s .... elements */

div[id^="s"] {
    color: red;
}

View google chrome's cached pictures

%UserProfile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Cache

paste this in your address bar and enter, you will get all the files

just rename the files extension into the extension which u r looking.

ie. open command prompt then

C:\>cd %UserProfile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Cache

then

C:\Users\User\AppData\Local\Google\Chrome\User Data\Default\Cache>ren *.* *.jpg

JQuery post JSON object to a server

To send json to the server, you first have to create json

function sendData() {
    $.ajax({
        url: '/helloworld',
        type: 'POST',
        contentType: 'application/json',
        data: JSON.stringify({
            name:"Bob",
            ...
        }),
        dataType: 'json'
    });
}

This is how you would structure the ajax request to send the json as a post var.

function sendData() {
    $.ajax({
        url: '/helloworld',
        type: 'POST',
        data: { json: JSON.stringify({
            name:"Bob",
            ...
        })},
        dataType: 'json'
    });
}

The json will now be in the json post var.

Set value to an entire column of a pandas dataframe

I had a similar issue before even with this approach df.loc[:,'industry'] = 'yyy', but once I refreshed the notebook, it ran well.

You may want to try refreshing the cells after you have df.loc[:,'industry'] = 'yyy'.

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