(PHP 5 >= 5.2.0, PHP 7) Gets a specific external variable by name and optionally filters it mixed filter_input ( int $type, string $variable_name [, int $filter = FILTER_DEFAULT [, mixed $options ]] ) Parameters: type One of INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV. variable_name Name of a variable to get.

(PHP 5 >= 5.2.0, PHP 7) Gets external variables and optionally filters them mixed filter_input_array ( int $type [, mixed $definition [, bool $add_empty = true ]] ) This function is useful for retrieving many values without repetitively calling filter_input(). Parameters: type One of INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.

(PHP 5 >= 5.2.0, PHP 7) Returns the filter ID belonging to a named filter int filter_id ( string $filtername ) Parameters: filtername Name of a filter to get. Returns: ID of a filter on success or FALSE if filter doesn't exist. See also: filter_list() -

(PHP 5 >= 5.2.0, PHP 7) Checks if variable of specified type exists bool filter_has_var ( int $type, string $variable_name ) Parameters: type One of INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV. variable_name Name of a variable to check. Returns: Returns TRUE on success or FALSE on failure.

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for character(s) representing a hexadecimal digit bool ctype_xdigit ( string $text ) Checks if all of the characters in the provided string, text, are hexadecimal 'digits'. Parameters: text The tested string. Returns: Returns TRUE if every character in text is a hexadecimal 'digit', that is a decimal digi

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for uppercase character(s) bool ctype_upper ( string $text ) Checks if all of the characters in the provided string, text, are uppercase characters. Parameters: text The tested string. Returns: Returns TRUE if every character in text is an uppercase letter in the current locale.

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for whitespace character(s) bool ctype_space ( string $text ) Checks if all of the characters in the provided string, text, creates whitespace. Parameters: text The tested string. Returns: Returns TRUE if every character in text creates some sort of white space, FALSE otherwise. Besides the blank character

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for any printable character which is not whitespace or an alphanumeric character bool ctype_punct ( string $text ) Checks if all of the characters in the provided string, text, are punctuation character. Parameters: text The tested string. Returns: Returns TRUE if every character in text is printable, but

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for printable character(s) bool ctype_print ( string $text ) Checks if all of the characters in the provided string, text, are printable. Parameters: text The tested string. Returns: Returns TRUE if every character in text will actually create output (including blanks). Returns FALSE if text contains contro

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Check for lowercase character(s) bool ctype_lower ( string $text ) Checks if all of the characters in the provided string, text, are lowercase letters. Parameters: text The tested string. Returns: Returns TRUE if every character in text is a lowercase letter in the current locale.