htmlentities

Description

string htmlentities ( string string [, int quote_style [, string charset [, bool double_encode]]] )

This function is identical to htmlspecialchars() in all ways, except with htmlentities(), all characters which have HTML character entity equivalents are translated into these entities.

Like htmlspecialchars(), the optional second quote_style parameter lets you define what will be done with 'single' and "double" quotes. It takes on one of three constants with the default being ENT_COMPAT:

表 1. Available quote_style 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.

Like htmlspecialchars(), it takes an optional third argument charset which defines character set used in conversion. Presently, the ISO-8859-1 character set is used as the default.

PHP 4.3.0 及其后续版本支持如下字符集。

表 2. 已支持字符集

字符集	别名	描述
ISO-8859-1	ISO8859-1	西欧，Latin-1
ISO-8859-15	ISO8859-15	西欧，Latin-9。增加了 Latin-1（ISO-8859-1）中缺少的欧元符号、法国及芬兰字母。
UTF-8		ASCII 兼容多字节 8-bit Unicode。
cp866	ibm866, 866	DOS-特有的 Cyrillic 字母字符集。PHP 4.3.2 开始支持该字符集。
cp1251	Windows-1251, win-1251, 1251	Windows-特有的 Cyrillic 字母字符集。PHP 4.3.2 开始支持该字符集。
cp1252	Windows-1252, 1252	Windows 对于西欧特有的字符集。
KOI8-R	koi8-ru, koi8r	俄文。PHP 4.3.2 开始支持该字符集。
BIG5	950	繁体中文，主要用于中国台湾。
GB2312	936	简体中文，国际标准字符集。
BIG5-HKSCS		繁体中文，Big5 的延伸，主要用于香港。
Shift_JIS	SJIS, 932	日文。
EUC-JP	EUCJP	日文。

注意: ISO-8859-1 将代替任何其它无法识别的字符集。

When double_encode is turned off PHP will not encode existing html entities. The default is to convert everything.

The double_quote parameter was added in PHP 5.2.3, charset in 4.1.0 and quote in PHP 4.0.3.

If you're wanting to decode instead (the reverse) you can use html_entity_decode().

例 1. A htmlentities() example

<?php
$str = "A 'quote' is <b>bold</b>";

// Outputs: A 'quote' is &lt;b&gt;bold&lt;/b&gt;
echo htmlentities($str);

// Outputs: A &#039;quote&#039; is &lt;b&gt;bold&lt;/b&gt;
echo htmlentities($str, ENT_QUOTES);
?>