In-depth analysis of mb_convert_encoding and iconv functions in PHP

In-depth analysis of mb_convert_encoding and iconv functions in PHP_PHP Tutorial

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Release： 2016-07-21 15:04:25

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mb_convert_encoding This function is used to convert encoding. I used to not understand the concept of program coding, but now I seem to understand a little bit.

However, English generally does not have encoding problems, only Chinese data will have this problem. For example, when you use Zend Studio or Editplus to write a program, you use gbk encoding. If the data needs to be entered into the database, and the database encoding is utf8, then the data must be encoded and converted, otherwise it will become garbled when entering the database. .
See the official usage of mb_convert_encoding:
http://php.net/manual/zh/function.mb-convert-encoding.php
Make a GBK To UTF-8

Copy code The code is as follows:

< ?php
header("content-Type: text/html; charset =Utf-8");
echo mb_convert_encoding("You are my friend", "UTF-8", "GBK");
?>

One more GB2312 To Big5

Copy code The code is as follows:

< ?php
header("content-Type: text /html; charset=big5");
echo mb_convert_encoding("You are my friend", "big5", "GB2312");
?>

But use The above function needs to be installed but the mbstring extension library needs to be enabled first.
Another function iconv in PHP is also used to convert string encoding, and its function is similar to the function above.
There are some detailed examples below:

Copy the code The code is as follows:

iconv — Convert string to requested character encoding
(PHP 4 >= 4.0.5, PHP 5)
mb_convert_encoding — Convert character encoding
(PHP 4 >= 4.0.6, PHP 5)
 

Usage:
string mb_convert_encoding ( string str, string to_encoding [, mixed from_encoding] )
You need to enable the mbstring extension library first, in php. ini; extension=php_mbstring.dll in front of; remove
mb_convert_encoding. You can specify multiple input encodings. It will automatically identify according to the content, but the execution efficiency is much worse than iconv;
string iconv ( string in_charset, string out_charset, string str )
Note: The second parameter, in addition to specifying the encoding to be converted to, can also add two suffixes: //TRANSLIT and //IGNORE, where //TRANSLIT will automatically convert characters that cannot be directly converted into one or more approximate characters, //IGNORE will ignore characters that cannot be converted, and the default effect is to start from the first illegal character. Character truncation.
Returns the converted string or FALSE on failure.
Use:
It is found that iconv will make an error when converting the character "-" to gb2312. If there is no ignore parameter, all characters following this character None of the strings can be saved. No matter what, this "-" cannot be converted successfully and cannot be output. In addition, mb_convert_encoding does not have this bug.

In general, iconv is used, and the mb_convert_encoding function is only used when it is difficult to determine what the original encoding is, or when the iconv conversion cannot be displayed normally.

Copy code The code is as follows:

from_encoding is specified by character code name before conversion. it can be array or string - comma separated enumerated list. If it is not specified, the internal encoding will be used.
/* Auto detect encoding from JIS, eucjp-win, sjis-win, then convert str to UCS-2LE */
$str = mb_convert_encoding($str, “UCS-2LE”, “JIS, eucjp-win, sjis-win”);
/* “auto” is expanded to “ASCII,JIS,UTF-8,EUC-JP,SJIS” */
$str = mb_convert_encoding($str, “ EUC-JP", "auto");

Example:

Copy code The code is as follows:

 
$content = iconv(”GBK”, “UTF-8″, $content);
$content = mb_convert_encoding($content, “UTF-8″, “GBK”);