preg_match numbers negative and positive

I need to fix this preg_match("/^[[0-9开发者_运维百科]{0,4}$/i", $input), it also need accept negative values. Thanks

if (preg_match('/^-?[0-9]{1,4}$/', $subject)) {
    # Successful match
} else {
    # Match attempt failed
}

Like everything else in PHP, there's a dedicated function.

Check out is_numeric()