(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.
支持以下字符集：
| 字符集 | 別名 | 描述 |
|---|---|---|
| ISO-8859-1 | ISO8859-1 | 西歐，Latin-1 |
| ISO-8859-5 | ISO8859-5 | Little used cyrillic charset (Latin/Cyrillic). |
| ISO-8859-15 | ISO8859-15 | 西歐，Latin-9。增加歐元符號(hào)，法語和芬蘭語字母在 Latin-1(ISO-8859-1) 中缺失。 |
| UTF-8 | ASCII 兼容的多字節(jié) 8 位 Unicode。 | |
| cp866 | ibm866, 866 | DOS 特有的西里爾編碼。本字符集在 4.3.2 版本中得到支持。 |
| cp1251 | Windows-1251, win-1251, 1251 | Windows 特有的西里爾編碼。本字符集在 4.3.2 版本中得到支持。 |
| cp1252 | Windows-1252, 1252 | Windows 特有的西歐編碼。 |
| KOI8-R | koi8-ru, koi8r | 俄語。本字符集在 4.3.2 版本中得到支持。 |
| BIG5 | 950 | 繁體中文，主要用于中國(guó)臺(tái)灣省。 |
| GB2312 | 936 | 簡(jiǎn)體中文，中國(guó)國(guó)家標(biāo)準(zhǔn)字符集。 |
| BIG5-HKSCS | 繁體中文，附帶香港擴(kuò)展的 Big5 字符集。 | |
| Shift_JIS | SJIS, 932 | 日語 |
| EUC-JP | EUCJP | 日語 |
| 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. |
注意: 其他字符集沒有認(rèn)可。將會(huì)使用默認(rèn)編碼并拋出異常。
Returns the decoded string.
| 版本 | 說明 |
|---|---|
| 8.1.0 |
flags changed from ENT_COMPAT to ENT_QUOTES | ENT_SUBSTITUTE | ENT_HTML401.
|
| 8.0.0 |
encoding is nullable now.
|
示例 #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 "walk" the <b>dog</b> now
echo $b; // I'll "walk" the <b>dog</b> now
?>
注意:
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.