PHP编码转换

要使用上面的函数需要安装但是需要先enable mbstring 扩展库。

 

mb_convert_encoding用法：
string mb_convert_encoding ( string str, string to_encoding [, mixed from_encoding] ) 
需要先enable mbstring 扩展库，在 php.ini里将; extension=php_mbstring.dll 前面的 ; 去掉 
mb_convert_encoding 可以指定多种输入编码，它会根据内容自动识别,但是执行效率比iconv差太多；

PHP中的另外一个函数iconv也是用来转换字符串编码的，与上函数功能相似。 
下面还有一些详细的例子： 
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)

iconv用法：  
string iconv ( string in_charset, string out_charset, string str ) 
注意：第二个参数，除了可以指定要转化到的编码以外，还可以增加两个后缀：//TRANSLIT 和 //IGNORE，其中 //TRANSLIT 会自动将不能直接转化的字符变成一个或多个近似的字符，//IGNORE 会忽略掉不能转化的字符，而默认效果是从第一个非法字符截断。 
Returns the converted string or FALSE on failure.

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iconv使用： 
发现iconv在转换字符”—”(ascii码150之后的字符)到gb2312时会出错，如果没有ignore参数，

所有该字符后面的字符串都无法被保存。不管怎么样，这个”—”都无法转换成功，无法输出。 另外mb_convert_encoding没有这个bug. 
一般情况下用 iconv，只有当遇到无法确定原编码是何种编码，或者iconv转化后无法正常显示时才用mb_convert_encoding 函数. 
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”);

iconv例子： 
以下为引用的内容： 

Java代码  

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

 
 

PHP中使用mb_convert_encoding转码的小陷阱
在php程序中使用mb_convert_encoding()方法进行字符编码转换大家都很熟悉了，平时也在大量的使用。

而且在一般情况下该方法也表现的足够好，值得表扬。但在一个项目中我们需要使用它进行UTF8到GBK的转换，

在转换一些特殊字符时发现了一个不大不小的问题。

具体表现为mb把在utf8可编码的字符而在gbk中不可编码的字符都转成了