(PHP 4, PHP 5, PHP 7)
htmlspecialchars — Convert special characters to HTML entities
$string
[, int $flags = ENT_COMPAT | ENT_HTML401
[, string $encoding = ini_get("default_charset")
[, bool $double_encode = true
]]] )Certain characters have special significance in HTML, and should be represented by HTML entities if they are to preserve their meanings. This function returns a string with these conversions made. If you require all input substrings that have associated named entities to be translated, use htmlentities() instead.
If the input string passed to this function and the final document share the same character set, this function is sufficient to prepare input for inclusion in most contexts of an HTML document. If, however, the input can represent characters that are not coded in the final document character set and you wish to retain those characters (as numeric or named entities), both this function and htmlentities() (which only encodes substrings that have named entity equivalents) may be insufficient. You may have to use mb_encode_numericentity() instead.
The translations performed are:
ENT_NOQUOTES
is not set.
ENT_QUOTES is set.
stringThe string being converted.
flagsA bitmask of one or more of the following flags, which specify how to handle quotes, invalid code unit sequences and the used document type. 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_IGNORE |
Silently discard invalid code unit sequences instead of returning an empty string. Using this flag is discouraged as it » may have security implications. |
ENT_SUBSTITUTE |
Replace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of returning an empty string. |
ENT_DISALLOWED |
Replace invalid code points for the given document type with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of leaving them as is. This may be useful, for instance, to ensure the well-formedness of XML documents with embedded external content. |
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, the default value of the encoding varies
depending on the PHP version in use. In PHP 5.6 and later, the
default_charset configuration
option is used as the default value. PHP 5.4 and 5.5 will use
UTF-8 as the default. Earlier versions of PHP use
ISO-8859-1.
Although this argument is technically optional, you are highly encouraged to specify the correct value for your code if you are using PHP 5.5 or earlier, or if your default_charset configuration option may be set incorrectly for the given input.
For the purposes of this function, the encodings
ISO-8859-1, ISO-8859-15,
UTF-8, cp866,
cp1251, cp1252, and
KOI8-R are effectively equivalent, provided the
string itself is valid for the encoding, as
the characters affected by htmlspecialchars() occupy
the same positions in all of these encodings.
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。
double_encode
When double_encode is turned off PHP will not
encode existing html entities, the default is to convert everything.
The converted string.
If the input string contains an invalid code unit
sequence within the given encoding an empty string
will be returned, unless either the ENT_IGNORE or
ENT_SUBSTITUTE flags are set.
| 版本 | 说明 |
|---|---|
| 5.6.0 |
The default value for the encoding parameter was
changed to be the value of the
default_charset configuration
option.
|
| 5.4.0 |
The default value for the encoding parameter was
changed to UTF-8.
|
| 5.4.0 |
The constants ENT_SUBSTITUTE, ENT_DISALLOWED,
ENT_HTML401, ENT_XML1,
ENT_XHTML and ENT_HTML5 were added.
|
| 5.3.0 |
The constant ENT_IGNORE was added.
|
| 5.2.3 |
The double_encode parameter was added.
|
Example #1 htmlspecialchars() example
<?php
$new = htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);
echo $new; // <a href='test'>Test</a>
?>
Note:
Note that this function does not translate anything beyond what is listed above. For full entity translation, see htmlentities().