html转义/html编码/html解码

html_entity_decode()函数把 HTML 实体转换为字符。html_entity_decode() 是 htmlentities() 的反函数。

htmlspecialchars_decode()函数把一些预定义的 HTML 实体转换为字符。htmlspecialchars() 函数把一些预定义的字符转换为 HTML 实体。

数据库的数据如果存的是实体的话，读取显示的时候就需要用到这两个函数，但是html_entity_decode函数有解析乱码的时候，而且用这个函数的时候还需要指定编码类型。所以就用htmlspecialchars_decode这个好了 。可是这两个有什么区别呢？

html_entity_decode

(PHP 4 >= 4.3.0, PHP 5)

html_entity_decode — Convert all HTML entities to their applicable characters


htmlspecialchars_decode

(PHP 5 >= 5.1.0)

htmlspecialchars_decode — Convert special HTML entities back to characters

名称

html_entity_decode

htmlspecialchars_decode

定义

Convert all HTML entities to their applicable characters

Convert special HTML entities back to characters

版本

(PHP 4 >= 4.3.0, PHP 5)

 (PHP 5 >= 5.1.0)

参数

(string $string [, int $flags = ENT_COMPAT | ENT_HTML401   [, string $encoding = 'UTF-8' ]])

 (string $string [, int $flags = ENT_COMPAT | ENT_HTML401 ]) 

                               
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From the PHP documentation for htmlentities:

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.

From the PHP documentation for htmlspecialchars:

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 some of these conversions made; the translations made are those most useful for everyday web programming. If you require all HTML character entities to be translated, use htmlentities() instead.

The difference is what gets encoded. The choices are everything (entities) or "special" characters, like ampersand, double and single quotes, less than, and greater than (specialchars).


I prefer to use htmlspecialchars whenever possible.

结论是，有中文的时候，最好用 htmlspecialchars ，否则可能乱码。

结论：htmlentities 和 htmlspecialchars 的区别在于 htmlentities 会转化所有的 html character entity，而htmlspecialchars 只会转化手册上列出的几个 html character entity （也就是会影响 html 解析的那几个基本字符）。一般来说，使用 htmlspecialchars 转化掉基本字符就已经足够了，没有必要使用 htmlentities。实在要使用 htmlentities 时，要注意为第三个参数传递正确的编码。

htmlspecialchars