html_entity_decode

(PHP 4 >= 4.3.0, PHP 5)

html_entity_decode --  Convert all HTML entities to their applicable characters

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 1. Available quote_style constants

Constant NameDescription
ENT_COMPATWill convert double-quotes and leave single-quotes alone.
ENT_QUOTESWill convert both double and single quotes.
ENT_NOQUOTESWill 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 2. Supported charsets

CharsetAliasesDescription
ISO-8859-1ISO8859-1 Western European, Latin-1
ISO-8859-15ISO8859-15 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.
cp866ibm866, 866 DOS-specific Cyrillic charset. This charset is supported in 4.3.2.
cp1251Windows-1251, win-1251, 1251 Windows-specific Cyrillic charset. This charset is supported in 4.3.2.
cp1252Windows-1252, 1252 Windows specific charset for Western European.
KOI8-Rkoi8-ru, koi8r Russian. This charset is supported in 4.3.2.
BIG5950 Traditional Chinese, mainly used in Taiwan.
GB2312936 Simplified Chinese, national standard character set.
BIG5-HKSCS  Big5 with Hong Kong extensions, Traditional Chinese.
Shift_JISSJIS, 932 Japanese
EUC-JPEUCJP Japanese

注意: Any other character sets are not recognized and ISO-8859-1 will be used instead.

例 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 &quot;walk&quot; the &lt;b&gt;dog&lt;/b&gt; 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

?>

注意: You might wonder why trim(html_entity_decode('&nbsp;')); doesn't reduce the string to an empty string, that's because the '&nbsp;' 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(), and urldecode().