PHP function htmlspecialchars - escaping characters

Available in PHP 4, 5, 7.

Converts special characters that have meaning in HTML to HTML entities that can be rendered in the normal way.

Parameters

Parameter	Data type	Default value	Note
$string	string	not	String to be converted.
$flags	int	ENT_COMPAT	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
$encoding	string	'UTF-8'	Defines the encoding used in conversion. If omitted, the default value for this argument is ISO-8859-1 in versions of PHP prior to 5.4.0, and UTF-8 from PHP 5.4.0 onwards.
$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 Modified string.

Other switches

Constant	Description
ENT_SUBSTITUTE	Replace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (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 &#FFFD; (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
	ENT_HTML5

Other resources

[Official htmlspecialchars documentation](- Official php.net documentation)

• STRING data type information
• UNICODE security and encoding information