What the array looks like:

  Array
(
    [int] => FILTER_VALIDATE_INT
    [boolean] => FILTER_VALIDATE_BOOLEAN
    [float] => FILTER_VALIDATE_FLOAT
    [validate_url] => FILTER_VALIDATE_URL
    [validate_email] => FILTER_VALIDATE_EMAIL
    [validate_ip] => FILTER_VALIDATE_IP
    [unsafe_raw] => FILTER_UNSAFE_RAW
    [string] => FILTER_SANITIZE_STRING
    [stripped] => FILTER_SANITIZE_STRIPPED
    [encoded] => FILTER_SANITIZE_ENCODED
    [special_chars] => FILTER_SANITIZE_SPECIAL_CHARS
    [email] => FILTER_SANITIZE_EMAIL
    [url] => FILTER_SANITIZE_URL
    [number_int] => FILTER_SANITIZE_NUMBER_INT
    [number_float] => FILTER_SANITIZE_NUMBER_FLOAT
    [magic_quotes] => FILTER_SANITIZE_MAGIC_QUOTES
)