mb_internal_encoding()

(PHP 4 >= 4.0.6, PHP 5, PHP 7)

设置/获取内部字符编码

说明

mb_internal_encoding ([string $encoding= mb_internal_encoding() ] ) : mixed

设置/获取内部字符编码

参数

$encoding

$encoding字符编码名称使用于 HTTP 输入字符编码转换、HTTP 输出字符编码转换、mbstring 模块系列函数字符编码转换的默认编码。 You should notice that the internal encoding is totally different from the one for multibyte regex.

返回值

如果设置了$encoding，则成功时返回 TRUE， 或者在失败时返回 FALSE。 In this case, the character encoding for multibyte regex is NOT changed. 如果省略了$encoding，则返回当前的字符编码名称。

范例

mb_internal_encoding() 例子

<?php
/* 设置内部字符编码为 UTF-8 */
mb_internal_encoding("UTF-8");
/* 显示当前的内部字符编码*/
echo mb_internal_encoding();
?>

参见

• mb_http_input()检测 HTTP 输入字符编码
• mb_http_output()设置/获取 HTTP 输出字符编码
• mb_detect_order()设置/获取 字符编码的检测顺序
• mb_regex_encoding()Set/Get character encoding for multibyte regex

Especially when writing PHP scripts for use on different servers, it is a very good idea to explicitly set the internal encoding somewhere on top of every document served, e.g.
mb_internal_encoding("UTF-8");
This, in combination with mysql-statement "SET NAMES 'utf8'", will save a lot of debugging trouble. 
Also, use the multi-byte string functions instead of the ones you may be used to, e.g. mb_strlen() instead of strlen(), etc.

Be aware that the strings in your source files must match the encoding you specify by mb_internal_encoding. It appears the Parser loads raw bytes from the file and refers to its internal encoding to determine their actual encoding.
To demonstrate, the following outputs as espected when the /source/ file is Latin-1 encoded:
<?php
  mb_internal_encoding("iso-8859-1");
  mb_http_output( "UTF-8" );
  ob_start("mb_output_handler");
  echo "<br/>";
  ?>
Now, a typical use of mb_internal_encoding is shown as follows. Make the change to "utf-8" but leave the /source/ file encoding unchanged:
<?php
  mb_internal_encoding("UTF-8");
  mb_http_output( "UTF-8" );
  ob_start("mb_output_handler");
  echo "<br/>";
  ?>
The output will just show the <br/> tag and no text.
Save the file as UTF-8 encoding and then the results will be as expected.

all together 
<?php
// ------------------------------------------------------------ 
header('Content-Type: text/html; charset=UTF-8');
mb_internal_encoding('UTF-8'); 
mb_http_output('UTF-8'); 
mb_http_input('UTF-8'); 
mb_regex_encoding('UTF-8'); 
// ------------------------------------------------------------ 
?>

Note that mb_internal_encoding is not necessary in PHP 5.6

In response to mortoray at ecircle-ag dot com:
The characters display fine as long as you set the Encoding to something more "Latin 1" compatible (i.e. US-ACSII, ISO-8859-1, ISO-8859-1, or Windows 1252). PHP.net auto-detects to UTF-8

i noticed that setting mb_internal_encoding('UTF-8') in my global site config.inc.php, doesn't work in my classes : it reverse back to ISO-8859-1.
Adding the call to the constructor of my top site class resolve this.

To previous example, the PHP notes don't appear to support umlauted characters so there are question marks (?) there instead of what should be umlauated oue. Just substitute any high-order/accented character to see the effect.