filter in php

filter.php

For Details on PHP Filter Functions, visit:
http://www.w3schools.com/php/php_ref_filter.asp
&
http://www.w3schools.com/php/php_filter.asp

PHP Filter Introduction

This PHP filters is used to validate and filter data coming from insecure sources, like user input.

PHP Filter Functions

PHP: indicates the earliest version of PHP that supports the function.
Function 	Description 	PHP
filter_has_var() 	Checks if a variable of a specified input type exist 	5
filter_id() 	Returns the ID number of a specified filter 	5
filter_input() 	Get input from outside the script and filter it 	5
filter_input_array() 	Get multiple inputs from outside the script and filters them 	5
filter_list() 	Returns an array of all supported filters 	5
filter_var_array() 	Get multiple variables and filter them 	5
filter_var() 	Get a variable and filter it 	5


PHP Filters

ID Name 	Description
FILTER_CALLBACK 	Call a user-defined function to filter data
FILTER_SANITIZE_STRING 	Strip tags, optionally strip or encode special characters
FILTER_SANITIZE_STRIPPED 	Alias of "string" filter
FILTER_SANITIZE_ENCODED 	URL-encode string, optionally strip or encode special characters
FILTER_SANITIZE_SPECIAL_CHARS 	HTML-escape '"<>& and characters with ASCII value less than 32
FILTER_SANITIZE_EMAIL 	Remove all characters, except letters, digits and !#$%&'*+-/=?^_`{|}~@.[]
FILTER_SANITIZE_URL 	Remove all characters, except letters, digits and $-_.+!*'(),{}|\\^~[]`<>#%";/?:@&=
FILTER_SANITIZE_NUMBER_INT 	Remove all characters, except digits and +-
FILTER_SANITIZE_NUMBER_FLOAT 	Remove all characters, except digits, +- and optionally .,eE
FILTER_SANITIZE_MAGIC_QUOTES 	Apply addslashes()
FILTER_UNSAFE_RAW 	Do nothing, optionally strip or encode special characters
FILTER_VALIDATE_INT 	Validate value as integer, optionally from the specified range
FILTER_VALIDATE_BOOLEAN 	Return TRUE for "1", "true", "on" and "yes", FALSE for "0", "false", "off", "no", and "", NULL otherwise
FILTER_VALIDATE_FLOAT 	Validate value as float
FILTER_VALIDATE_REGEXP 	Validate value against regexp, a Perl-compatible regular expression
FILTER_VALIDATE_URL 	Validate value as URL, optionally with required components
FILTER_VALIDATE_EMAIL 	Validate value as e-mail
FILTER_VALIDATE_IP 	Validate value as IP address, optionally only IPv4 or IPv6 or not from private or reserved ranges