(PHP 4 >= 4.3.0, PHP 5)
html_entity_decode — Convert all HTML entities to their applicable characters
$string
[, int $flags = ENT_COMPAT | ENT_HTML401
[, string $encoding = "UTF-8"
]] )
html_entity_decode() is the opposite of
htmlentities() in that it converts all HTML entities
in the string to their applicable 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.
flagsA 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_COMPAT | 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_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. |
encodingEncoding to use. If omitted, the default value for this argument is ISO-8859-1 in versions of PHP prior to 5.4.0, and UTF-8 from PHP 5.4.0 onwards.
支持以下字符集：
| 字符集 | 别名 | 描述 |
|---|---|---|
| ISO-8859-1 | ISO8859-1 | 西欧，Latin-1 |
| ISO-8859-5 | ISO8859-5 | Little used cyrillic charset (Latin/Cyrillic). |
| ISO-8859-15 | ISO8859-15 | 西欧，Latin-9。增加欧元符号，法语和芬兰语字母在 Latin-1(ISO-8859-1) 中缺失。 |
| UTF-8 | ASCII 兼容的多字节 8 位 Unicode。 | |
| cp866 | ibm866, 866 | DOS 特有的西里尔编码。本字符集在 4.3.2 版本中得到支持。 |
| cp1251 | Windows-1251, win-1251, 1251 | Windows 特有的西里尔编码。本字符集在 4.3.2 版本中得到支持。 |
| cp1252 | Windows-1252, 1252 | Windows 特有的西欧编码。 |
| KOI8-R | koi8-ru, koi8r | 俄语。本字符集在 4.3.2 版本中得到支持。 |
| BIG5 | 950 | 繁体中文，主要用于中国台湾省。 |
| GB2312 | 936 | 简体中文，中国国家标准字符集。 |
| BIG5-HKSCS | 繁体中文，附带香港扩展的 Big5 字符集。 | |
| Shift_JIS | SJIS, 932 | 日语 |
| EUC-JP | EUCJP | 日语 |
| MacRoman | Mac OS 使用的字符串。 | |
| '' | 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: 其他字符集没有认可。将会使用默认编码并抛出异常。
Returns the decoded string.
| 版本 | 说明 |
|---|---|
| 5.4.0 | Default encoding changed from ISO-8859-1 to UTF-8. |
| 5.4.0 |
The constants ENT_HTML401, ENT_XML1,
ENT_XHTML and ENT_HTML5 were added.
|
| 5.0.0 | Support for multi-byte encodings was added. |
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.