`iconv()` is just a wrapper around the `iconv()` function found in the system C library where PHP is running (unless PHP is built with GNU iconv, in which case GNU iconv is used). So the performance and features of `iconv()` depend on where you are running PHP and how it is built.

The implementation of `mb_convert_encoding()`, on the other hand, is included in the PHP (module) source. It includes a library called libmbfl which handles the actual conversion. Thus it works the same regardless of where you&#39;re running PHP. There is a list of supported encodings here: http://php.net/manual/en/mbstring.encodings.php

So, in summary, I guess you could say that `mb_convert_encoding()` is more reliable to use if you want to support different platforms. However, if you use `iconv()` on Linux (for example), then it supports a lot more encodings (see `iconv --list`).

The relative performance of the functions also depends on the specific `iconv()` implementation, obviously.

Since PHP 5.4 there is a bug.
Sometime iconv returns null string instead of returning a string with &#39;similar&#39; char.

So you should use mb_convert_encoding.

Seems like such a simple thing but I cannot for the life of me figure out how to do this.

How do I jump to a specific line of code in Xcode?

I&#39;d like to create a JSON string containing the instance variables of my class.

For example,

    class Example {  
        std::string string;  
        std::map&lt;std::string, std:string&gt; map;  
        std::vector&lt;int&gt; vector;  
    };

would become:

    {
        &quot;string&quot;:&quot;the-string-value&quot;,
        &quot;map&quot;: {
            &quot;key1&quot;:&quot;val1&quot;,
            &quot;key2&quot;:&quot;val2&quot;
        },
        &quot;vector&quot;:[1,2,3,4]
    }

I&#39;ve looked into several C++ libraries for creating JSON and they all seem incredibly complex. I&#39;d like something similar to Javascript&#39;s `JSON.stringify(object)`. In other words just pass a std::map to it and receive a string. The map could contain other maps, vectors, lists, strings, numbers and bools.

What&#39;s the nicest way to do this?

Thanks for your help.

**Edit**

I&#39;ve looked into the following:

json spirit, jsoncpp, zoolib, JOST, CAJUN, libjson, nosjob, JsonBox, jsonme--

Which I understand I can construct a separate JSON object as in an answer below and convert to JSON I&#39;d like to be able to store my stuff in standard collections and convert.

**Edit 2**

Okay, scrap the idea of serializing a class since it appears that&#39;s impossible with C++&#39;s lack of reflection.

Is there a nice way to convert a std::map containing std:maps, std::vectors, std::lists, numbers, strings, and bools to JSON without having to change datatypes or copying data to a new datatype?

Thanks.

Converting C++ class to JSON

What&#39;s the difference between `iconv()` and `mb_convert_encoding()` in PHP?  Does one perform better, faster, etc. ( eg. with specific encodings )? In what situations would one be preferred over the other?

Here&#39;s what I think I know already:

**iconv()**

1. included with most installs of PHP.
2. when characters that can&#39;t be mapped to the new character set are found, you can specify if they are converted to a &#39;similar&#39; character, or ignored.

**mb_convert_encoding()**

1. usually requires installing the php-mbstring extension.
2. is able to handle `HTML-ENTITIES`, converting to and from web hex codes.

Are there other differences?

What is the difference between iconv() and mb_convert_encoding() in PHP?

What's the difference between <code>iconv()</code> and <code>mb_convert_encoding()</code> in PHP? Does one perform better, faster, etc. ( eg. with specific encodings )? In what situations would one be preferred over the other?
Here's what I think I know already:
iconv()
<ol>
<li>included with most installs of PHP.</li>
<li>when characters that can't be mapped to the new character set are found, you can specify if they are converted to a 'similar' character, or ignored.</li>
</ol>
mb_convert_encoding()
<ol>
<li>usually requires installing the php-mbstring extension.</li>
<li>is able to handle <code>HTML-ENTITIES</code>, converting to and from web hex codes.</li>
</ol>
Are there other differences?

I have a question regarding `NULL` in PHP:

      $a = &#39;&#39;;
      if($a == NULL) {
          echo &#39;is null&#39;;
      }

Why do I see **is null** when `$a` is an empty string? Is that a bug?

php is null when empty?

    $arr = array(); // is this line needed?
    $arr[] = 5;

I know it works without the first line, but it&#39;s often included in practice. 

What is the reason? Is it unsafe without it?

I know you can also do this:

     $arr = array(5);

but I&#39;m talking about cases where you need to add items one by one.

Is it necessary to declare PHP array before adding values with []?

Is there a PHP function that can do that?

I&#39;m using `strpos` to get the position of a substring and I want to insert a `string` after that position.

Insert string at specified position

I would like to convert a variable `$uptime` which is seconds, into days, hours, minutes and seconds.

Example:

&lt;!-- language: php --&gt;

    $uptime = 1640467;

Result should be: 

&lt;!-- language: none --&gt;

    18 days 23 hours 41 minutes


Convert seconds into days, hours, minutes and seconds

I want to know what is the best way to benchmark my PHP scripts. Does not matter if a cron job, or webpage or web service.

I know i can use microtime but is it really giving me the real time of a PHP script?

I want to test and benchmark different functions in PHP that do the same thing. For example, `preg_match` vs `strpos` or `domdocument` vs `preg_match` or preg_replace vs str_replace`

Example of a webpage:

    &lt;?php
    // login.php
    
    $start_time = microtime(TRUE);
    
    session_start(); 
    // do all my logic etc...
    
    $end_time = microtime(TRUE);
    
    echo $end_time - $start_time;

This will output: 0.0146126717 (varies all the time - but that is the last one I got). This means it took 0.015 or so to execute the PHP script.

Is there a better way?

How to benchmark efficiency of PHP script

I am compiling a package using maven and it says build failure with following compilation error:

SpanishTest.java[31, 81] unmappable character for encoding UTF8

I searched online and for many people, changing source encoding from UTF-8 to ISO-8859-1 seems to work but I am still getting same compilation error. I am using 32-bit Ubuntu. Here is how that tag looks in my pom.xml

    &lt;project.build.sourceEncoding&gt;ISO-8859-1&lt;/project.build.sourceEncoding&gt;

Even if I change `&lt;project.build.outputEncoding&gt;` tag to ISO-8859-1, I still get the error.Could it be because of java version? I have both-sun java and openjdk installed on my system.

Can anyone please let me know what to do.

Thanks  

Error: unmappable character for encoding UTF8 during maven compilation

How can I add UTF-8 support in eclipse? I want to add for example Russian language but eclipse won&#39;t support it. What should I do? Please guide me.

How to support UTF-8 encoding in Eclipse

For layouting we have our famous &quot;Lorem ipsum&quot; text to test how it looks like.

What I am looking for is a set of files containing Text encoded with several different encodings that I can use in my JUnit tests to test some methods that are dealing with character encoding when reading text files.

#### Example: ####
Having a `ISO 8859-1` encoded test-file and a `Windows-1252` encoded test-file. The Windows-1252 have to trigger the differences in region 80&lt;sub&gt;16&lt;/sub&gt; – 9F&lt;sub&gt;16&lt;/sub&gt;. In other words it must contain at least one character of this region to distinguish it from ISO 8859-1.

Maybe the best set of test-files is that where the test-file for each encoding contains all its characters once. But maybe I am not aware of sth - we all like this encoding stuff, right? :-)

**Is there such a set of test-files for character-encoding issues out there?**

Is there a set of &quot;Lorem ipsums&quot; files for testing character encoding issues?

When I make a POST request with a JSON body to my REST service I include `Content-type: application/json; charset=utf-8` in the message header. Without this header, I get an error from the service. I can also successfully use `Content-type: application/json` without the `;charset=utf-8` portion. 

What exactly does `charset=utf-8` do ? I know it specifies the character encoding but the service works fine without it. Does this encoding limit the characters that can be in the message body?

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

Only today I realized that I was missing this in my PHP scripts:

    mysql_set_charset(&#39;utf8&#39;);

All my tables are InnoDB, collation &quot;utf8_unicode_ci&quot;, and all my VARCHAR columns are &quot;utf8_unicode_ci&quot; as well. I have `mb_internal_encoding(&#39;UTF-8&#39;);` on my PHP scripts, and all my PHP files are encoded as UTF-8.

So, until now, every time I &quot;INSERT&quot; something with diacritics, example:

    mysql_query(&#39;INSERT INTO `table` SET `name`=&quot;J&#225;u&#242; I&#241;e&quot;&#39;);

The &#39;name&#39; contents would be, in this case: `J&#195;&#161;u&#195;&#178; I&#195;&#177;e`.  

Since I fixed the charset between PHP and MySQL, new INSERTs are now storing correctly. However, I want to fix all the older rows that are &quot;messed&quot; at the moment. I tried many things already, but it always breaks the strings on the first &quot;illegal&quot; character. Here is my current code:

    $m = mysql_real_escape_string(&#39;&#191;&lt;?php echo &quot;&#172;&lt;b&gt;\&#39;PHP &amp;aacute; (&#225;)ţări&#238;ş &lt;/b&gt;&quot;; ?&gt; ă-ţi abcdd;//;&#241;&#231;&#180;พดแทฝใจค&#231;ă&#226;ξβψδπλξξςαยน&#241; ;&#39;);
	mysql_set_charset(&#39;utf8&#39;);
	mysql_query(&#39;INSERT INTO `table` SET `name`=&quot;&#39;.$m.&#39;&quot;&#39;);
	mysql_set_charset(&#39;latin1&#39;);
	mysql_query(&#39;INSERT INTO `table` SET `name`=&quot;&#39;.$m.&#39;&quot;&#39;);
	mysql_set_charset(&#39;utf8&#39;);
	
	$result = mysql_iquery(&#39;SELECT * FROM `table`&#39;);
	while ($row = mysql_fetch_assoc($result)) {
		$message = $row[&#39;name&#39;];
		$message = mb_convert_encoding($message, &#39;ISO-8859-15&#39;, &#39;UTF-8&#39;);
		//$message = iconv(&quot;UTF-8&quot;, &quot;ISO-8859-1//IGNORE&quot;, $message);
		mysql_iquery(&#39;UPDATE `table` SET `name`=&quot;&#39;.mysql_real_escape_string($message).&#39;&quot; WHERE `a1`=&quot;&#39;.$row[&#39;a1&#39;].&#39;&quot;&#39;);
	}

It &quot;UPDATE&quot;s with the expected characters, except that the string gets truncated after the character &quot;ă&quot;. I mean, that character and following chars are not included on the string.

Also, testing with the &quot;iconv()&quot; (that is commented on the code) does the same, even with //IGNORE and //TRANSLIT

I also tested several charsets, between ISO-8859-1 and ISO-8859-15.

Convert latin1 characters on a UTF8 table into UTF8

**What is the best way to check the text area value for line breaks and then calculate the number of occurrences, if any?**

I have a text area on a form on my webpage. I am using JavaScript to grab the value of the text area and then checking its length.

### Example

    enteredText = textareaVariableName.val();
    characterCount = enteredText.length; // One line break entered returns 1

If a user enters a line break in the text area my calculation above gives the line break a length of 1. However I need to give line breaks a length of 2. Therefore I need to check for line breaks and the number of occurrences and then add this onto the total length.

### Example of what I want to achieve

    enteredText = textareaVariableName.val();
    characterCount = enteredText.length + numberOfLineBreaks;

----------

My solution before asking this question was the following:

    enteredText = textareaVariableName.val();
    enteredTextEncoded = escape(enteredText);
    linebreaks = enteredTextEncoded.match(/%0A/g);
    (linebreaks != null) ? numberOfLineBreaks = linebreaks.length : numberOfLineBreaks = 0;

I could see that encoding the text and checking for `%0A` was a bit long-winded, so I was after some better solutions. Thank you for all the suggestions.


How to detect line breaks in a text area input?

I have a log file (application.log) which might contain the following string of normal &amp; special characters on multiple lines:

    *^%Q&amp;$*&amp;^@$&amp;*!^@$*&amp;^&amp;^*&amp;^&amp;

I want to search for the line number(s) which contains this special character string.

&lt;!-- language: sh --&gt;

    grep &#39;*^%Q&amp;$*&amp;^@$&amp;*!^@$*&amp;^&amp;^*&amp;^&amp;&#39; application.log

The above command doesn&#39;t return any results.

What would be the correct syntax to get the line numbers?

grep for special characters in Unix

I&#39;m generating a CSV file (delimited by commas rather than tabs). My users will most likely open the CSV file in Excel by double clicking it. My data may contain commas and speech marks, so I&#39;m escaping those as follows.

    Reference, Title, Description
    1, &quot;My little title&quot;, &quot;My description, which may contain &quot;&quot;speech marks&quot;&quot; and commas.&quot;
    2, &quot;My other little title&quot;, &quot;My other description, which may also contain &quot;&quot;speech marks&quot;&quot; and commas.&quot;

As far as I know that&#39;s always been the way to do it. Here&#39;s my boggle: when I open this file in Excel 2010 my escaping is not respected. Speech marks appear on the sheet, and the comma causes new columns.



How should I escape commas and speech marks in CSV files so they work in Excel?

I am trying to validate a string, that should contain letters numbers and special characters `&amp;-._` only. For that I tried with a regular expression.

    var pattern = /[a-zA-Z0-9&amp;_\.-]/
    var qry = &#39;abc&amp;*&#39;;
    if(qry.match(pattern)) {
        alert(&#39;valid&#39;);
    }
    else{
        alert(&#39;invalid&#39;);
    }

While using the above code, the string `abc&amp;*` is valid. But my requirement is to show this invalid. ie Whenever a character other than a letter, a number or special characters `&amp;-._` comes, the string should evaluate as invalid. How can I do that with a regex? 

Matching special characters and letters in regex

Is there any comprehensive list of characters that need to be escaped in Bash? Can it be checked just with `sed`?

In particular, I was checking whether `%` needs to be escaped or not. I tried

    echo &quot;h%h&quot; | sed &#39;s/%/i/g&#39;

and worked fine, without escaping `%`. Does it mean `%` does not need to be escaped? Was this a good way to check the necessity?

And more general: are they the same characters to escape in `shell` and `bash`?

Content Type	Original Author	Original Content on Stackoverflow
Question	T. Brian Jones	View Question on Stackoverflow
Solution 1 - Php	pelle	View Answer on Stackoverflow
Solution 2 - Php	webshaker	View Answer on Stackoverflow

What is the difference between iconv() and mb_convert_encoding() in PHP?

Php Problem Overview

Php Solutions

Solution 1 - Php

Solution 2 - Php

Converting C++ class to JSON

How do I jump to a specific line of code in Xcode?

Attributions