(PHP 4 = 4.3.0) html_entity_decode() is the opposite of htmlentities() in that it converts all HTML entities to their applicable characters from string. 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 1Available quote_style constants The ISO-8859-1 character set is used as default for the optional third charset. This defines the character set used in conversion. 例 1Decoding html entities 注意 You might wonder why trim(html_entity_decode(' nbsp;')); doesn't reduce the string to an empty string, that's because the 'nbsp;' entity is not ASCII code 32 (which is stripped by trim()) but ASCII code 160 (0xa0) in the default ISO 8859-1 characterset. See also htmlentities(), htmlspecialchars(), get_html_translation_table(), htmlspecialchars() and urldecode().