PHP function htmlentities()

Availability in PHP 4.0

Convert all applicable characters to HTML entities

Parameters

Parameter	Data type	Default value	Note
$string	string	not	String being processed.
$quote_style	int	null,	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: 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.
$charset	string	null,	Like htmlspecialchars, it takes an optional third argument charset which defines the character set used in conversion. Presently, the ISO-8859-1 character set is used as the default.
$double_encode	bool	true	When double_encode is turned off PHP will not encode existing html entities. The default is to convert everything.

Return values

string

the encoded string.

Other resources

Official htmlentities documentation