php filters

if (filter_input(INPUT_GET, "num", FILTER_VALIDATE_INT)) {

}

• Filter Functions
• filter_has_var — Checks if variable of specified type exists
• filter_id — Returns the filter ID belonging to a named filter
• filter_input_array — Gets external variables and optionally filters them
• filter_input — Gets a specific external variable by name and optionally filters it
• filter_list — Returns a list of all supported filters
• filter_var_array — Gets multiple variables and optionally filters them
• filter_var — Filters a variable with a specified filter
• http://php.net/manual/en/filter.filters.validate.php

    [0] => int
    [1] => boolean
    [2] => float
    [3] => validate_regexp
    [4] => validate_url
    [5] => validate_email
    [6] => validate_ip
    [7] => string
    [8] => stripped
    [9] => encoded
    [10] => special_chars
    [11] => unsafe_raw
    [12] => email
    [13] => url
    [14] => number_int
    [15] => number_float
    [16] => magic_quotes
    [17] => callback
)