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:

Table 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.

Table 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

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

Note: This function doesn't support multi-byte character sets in PHP < 5.

Example 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)
{
    
// replace numeric entities
    
$string = preg_replace('~&#x([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $string);
    
$string = preg_replace('~&#([0-9]+);~e', 'chr(\\1)', $string);
    
// replace literal entities
    
$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

?>

Note: 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().