Description
string 
html_entity_decode ( string string [, int quote_style [, string charset]])
     html_entity_decode() is the opposite of
     htmlentities() in that it converts all HTML entities
     to their applicable characters from string.
    
     The optional second quote_style parameter lets 
     you define what will be done with 'single' and "double" quotes.  It takes 
     on one of three constants with the default being 
     ENT_COMPAT:
     
表格 1. Available quote_style constants
| Constant Name | Description | 
|---|
| ENT_COMPAT | Will convert double-quotes and leave single-quotes alone. | 
| ENT_QUOTES | Will convert both double and single quotes. | 
| ENT_NOQUOTES | Will leave both double and single quotes unconverted. | 
     The ISO-8859-1 character set is used as default for the optional third
     charset. This defines the character set used in
     conversion.
    
 Following character sets are supported in PHP 4.3.0 and later.
 
表格 2. Supported charsets
| Charset | Aliases | Description | 
|---|
| ISO-8859-1 | ISO8859-1 | Western European, Latin-1 | 
| ISO-8859-15 | ISO8859-15 | Western European, Latin-9. Adds the Euro sign, French and Finnish
      letters missing in Latin-1(ISO-8859-1). | 
| UTF-8 |  | ASCII compatible multi-byte 8-bit Unicode. | 
| cp866 | ibm866, 866 | DOS-specific Cyrillic charset.
      This charset is supported in 4.3.2. | 
| cp1251 | Windows-1251, win-1251, 1251 | Windows-specific Cyrillic charset.
      This charset is supported in 4.3.2. | 
| cp1252 | Windows-1252, 1252 | Windows specific charset for Western European. | 
| KOI8-R | koi8-ru, koi8r | Russian. This charset is supported in 4.3.2. | 
| BIG5 | 950 | Traditional Chinese, mainly used in Taiwan. | 
| GB2312 | 936 | Simplified Chinese, national standard character set. | 
| BIG5-HKSCS |  | Big5 with Hong Kong extensions, Traditional Chinese. | 
| Shift_JIS | SJIS, 932 | Japanese | 
| EUC-JP | EUCJP | Japanese | 
注: 
   Any other character sets are not recognized and ISO-8859-1 will be used
   instead.
  
     
| 例子 1. Decoding HTML entities | 
<?php$orig = "I'll \"walk\" the <b>dog</b> now";
 
 $a = htmlentities($orig);
 
 $b = html_entity_decode($a);
 
 echo $a; // I'll "walk" the <b>dog</b> now
 
 echo $b; // I'll "walk" the <b>dog</b> now
 
 
 // For users prior to PHP 4.3.0 you may do this:
 function unhtmlentities($string)
 {
 $trans_tbl = get_html_translation_table(HTML_ENTITIES);
 $trans_tbl = array_flip($trans_tbl);
 return strtr($string, $trans_tbl);
 }
 
 $c = unhtmlentities($a);
 
 echo $c; // I'll "walk" the <b>dog</b> now
 
 ?>
 | 
 | 
    
     
注: 
       You might wonder why trim(html_entity_decode(' ')); doesn't
       reduce the string to an empty string, that's because the ' '
       entity is not ASCII code 32 (which is stripped by
       trim()) but ASCII code 160 (0xa0) in the default ISO
       8859-1 characterset.
      
     See also htmlentities(),
     htmlspecialchars(),
     get_html_translation_table(), 
     htmlspecialchars() and urldecode().