(Filter and Escape) PHP comes with filter and escape functions

Name of function	Use	Note
Htmlspecialchars	will be with &&, single and double quotes ' ", Greater than >, less than < turns into HTML format	&&->&amp '->& #039 "->&quot <->&lt >->&gt
Htmlentities	Turn all characters into HTML format	Except with &&, single and double quotes '/', Greater than >, less than <, and also includes double-byte character display as encoding, etc.
Addslashes	Place single double quote ' ", backslash backslash\, NULL Plus backslash \ Escape	\‘ \" \\ \null
Stripslashes	Remove backslash characters	Remove the backslash character in the string, if two consecutive, Then remove a
Quotemeta	Add Reference symbol	The string that contains the. \\ + * ? [ ^ ] ($) and other characters. preceded by a backslash \ Symbol
Nl2br	Turn line break \ n to <br>	<br> for HTML format
Strip_tags	Remove HTML and PHP tags	Remove any HTML and PHP tags from the string, including tags Content, note that if there are errors in the string HTML and PHP tags, it will also return error
Mysql_real_escape_string	Escaping special characters in SQL strings	Escape \x00 \ r \ n space \ ' "\x1a, which is useful for multibyte character processing, which determines the character set, mysql_escape_string does not consider
Base64_decode	Base64 decoding	Decoding data that uses MIME base64 encoding
Base64_encode	Base64 encoding	Encode data using MIME base64
Rawurldecode	URL decoding	Decoding an encoded URL string
Rawurlencode	URL encoding	Encode URLs according to RFC 1738
UrlDecode	URL decoding	Decodes an encoded URL string
UrlEncode	URL encoding	Encoded URL string

(Filter and Escape) PHP comes with filter and escape functions