htmlspecialchars

参数

string

The string being converted.

flags

A 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.

Available flags constants

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 � (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 � (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.

encoding

An 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：

支持的字符集列表

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.