(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
html_entity_decode — Convert HTML entities to their corresponding characters
$string, int $flags = ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401, ?string $encoding = null): string
html_entity_decode() is the opposite of
htmlentities() in that it converts HTML entities
in the string to their corresponding characters.
More precisely, this function decodes all the entities (including all numeric entities) that a) are necessarily valid for the chosen document type — i.e., for XML, this function does not decode named entities that might be defined in some DTD — and b) whose character or characters are in the coded character set associated with the chosen encoding and are permitted in the chosen document type. All other entities are left as is.
stringThe input string.
flags
A bitmask of one or more of the following flags, which specify how to handle quotes and
which document type to use. The default is ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401.
| 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. |
ENT_SUBSTITUTE |
Replace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or � (otherwise) instead of returning an empty string. |
ENT_HTML401 |
Handle code as HTML 4.01. |
ENT_XML1 |
Handle code as XML 1. |
ENT_XHTML |
Handle code as XHTML. |
ENT_HTML5 |
Handle code as HTML 5. |
encodingAn optional argument defining the encoding used when converting characters.
If omitted, encoding defaults to the value of the
default_charset configuration
option.
Although this argument is technically optional, you are highly encouraged to specify the correct value for your code if the default_charset configuration option may be set incorrectly for the given input.
The following character sets are supported:
| Charset | Aliases | Description |
|---|---|---|
| ISO-8859-1 | ISO8859-1 | Western European, Latin-1. |
| ISO-8859-5 | ISO8859-5 | Little used cyrillic charset (Latin/Cyrillic). |
| 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. |
| cp1251 | Windows-1251, win-1251, 1251 | Windows-specific Cyrillic charset. |
| cp1252 | Windows-1252, 1252 | Windows specific charset for Western European. |
| KOI8-R | koi8-ru, koi8r | Russian. |
| 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, SJIS-win, cp932, 932 | Japanese |
| EUC-JP | EUCJP, eucJP-win | Japanese |
| MacRoman | Charset that was used by Mac OS. | |
'' |
An empty string activates detection from script encoding (Zend multibyte), default_charset and current locale (see nl_langinfo() and setlocale()), in this order. Not recommended. |
Note: Any other character sets are not recognized. The default encoding will be used instead and a warning will be emitted.
Returns the decoded string.
| Version | Description |
|---|---|
| 8.1.0 |
flags changed from ENT_COMPAT to ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401.
|
| 8.0.0 |
encoding is nullable now.
|
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 "walk" the <b>dog</b> now
echo $b; // I'll "walk" the <b>dog</b> now
?>Note:
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 encoding.
If you need something that converts &#[0-9]+ entities to UTF-8, this is simple and works:
<?php
/* Entity crap. /
$input = "Fovič";
$output = preg_replace_callback("/(&#[0-9]+;)/", function($m) { return mb_convert_encoding($m[1], "UTF-8", "HTML-ENTITIES"); }, $input);
/* Plain UTF-8. */
echo $output;
?>Use the following to decode all entities:
<?php html_entity_decode($string, ENT_QUOTES | ENT_XML1, 'UTF-8') ?>
I've checked these special entities:
- double quotes (")
- single quotes (' and ')
- non printable chars (e.g. )
With other $flags some or all won't be decoded.
It seems that ENT_XML1 and ENT_XHTML are identical when decoding.This functionality is now implemented in the PEAR package PHP_Compat.
More information about using this function without upgrading your version of PHP can be found on the below link:
http://pear.php.net/package/PHP_CompatThe following function decodes named and numeric HTML entities and works on UTF-8. Requires iconv.
function decodeHtmlEnt($str) {
$ret = html_entity_decode($str, ENT_COMPAT, 'UTF-8');
$p2 = -1;
for(;;) {
$p = strpos($ret, '&#', $p2+1);
if ($p === FALSE)
break;
$p2 = strpos($ret, ';', $p);
if ($p2 === FALSE)
break;
if (substr($ret, $p+2, 1) == 'x')
$char = hexdec(substr($ret, $p+3, $p2-$p-3));
else
$char = intval(substr($ret, $p+2, $p2-$p-2));
//echo "$char\n";
$newchar = iconv(
'UCS-4', 'UTF-8',
chr(($char>>24)&0xFF).chr(($char>>16)&0xFF).chr(($char>>8)&0xFF).chr($char&0xFF)
);
//echo "$newchar<$p<$p2<<\n";
$ret = substr_replace($ret, $newchar, $p, 1+$p2-$p);
$p2 = $p + strlen($newchar);
}
return $ret;
}I wanted to use this function today and I found the documentation, especially about the flags, not particularly helpful.
Running the code below, for example, failed because the flag I used was the wrong one...
$string = 'Donna's Bakery';
$title = html_entity_decode($string, ENT_HTML401, 'UTF-8');
echo $title;
The correct flag to use in this case is ENT_QUOTES.
My understanding of the flag to use is the one that would correspond to the expected, converted outcome. So, ENT_QUOTES for a character that would be a single or double quote when converted... and so on.
Please help make the documentation a bit clearer.Quick & dirty code that translates numeric entities to UTF-8.
<?php
function replace_num_entity($ord)
{
$ord = $ord[1];
if (preg_match('/^x([0-9a-f]+)$/i', $ord, $match))
{
$ord = hexdec($match[1]);
}
else
{
$ord = intval($ord);
}
$no_bytes = 0;
$byte = array();
if ($ord < 128)
{
return chr($ord);
}
elseif ($ord < 2048)
{
$no_bytes = 2;
}
elseif ($ord < 65536)
{
$no_bytes = 3;
}
elseif ($ord < 1114112)
{
$no_bytes = 4;
}
else
{
return;
}
switch($no_bytes)
{
case 2:
{
$prefix = array(31, 192);
break;
}
case 3:
{
$prefix = array(15, 224);
break;
}
case 4:
{
$prefix = array(7, 240);
}
}
for ($i = 0; $i < $no_bytes; $i++)
{
$byte[$no_bytes - $i - 1] = (($ord & (63 * pow(2, 6 * $i))) / pow(2, 6 * $i)) & 63 | 128;
}
$byte[0] = ($byte[0] & $prefix[0]) | $prefix[1];
$ret = '';
for ($i = 0; $i < $no_bytes; $i++)
{
$ret .= chr($byte[$i]);
}
return $ret;
}
$test = 'This is a čא test'';
echo $test . "<br />\n";
echo preg_replace_callback('/&#([0-9a-fx]+);/mi', 'replace_num_entity', $test);
?>I wrote in a previous comment that html_entity_decode() only handled about 100 characters. That's not quite true; it only handles entities that exist in the output character set (the third argument). If you want to get ALL HTML entities, make sure you use ENT_QUOTES and set the third argument to 'UTF-8'.
If you don't want a UTF-8 string, you'll need to convert it afterward with something like utf8_decode(), iconv(), or mb_convert_encoding().
If you're producing XML, which doesn't recognise most HTML entities:
When producing a UTF-8 document (the default), then htmlspecialchars(html_entity_decode($string, ENT_QUOTES, 'UTF-8'), ENT_NOQUOTES, 'UTF-8') (because you only need to escape < and > and & unless you're printing inside the XML tags themselves).
Otherwise, either convert all the named entities to numeric ones, or declare the named entities in the document's DTD. The full list of 252 entities can be found in the HTML 4.01 Spec, or you can cut and paste the function from my site (http://inanimatt.com/php-convert-entities.php).