filter_has_var

(PHP 5 >= 5.2.0)

filter_has_var — Checks if variable of specified type exists

bool filter_has_var ( int $type , string $variable_name )

type: One of INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.
variable_name: Name of a variable to check.

成功时返回 TRUE，或者在失败时返回 FALSE.