4 ms·

is_numeric() has been available since forever, and is intended for exactly the thing you appear to want to do. https://www.php.net/manual/en/function.is-numeri

• deathanatos 4y ago
  At this point you're writing the parser that ships in most language's standard libraries. And, if you naïvely use the suggested function for the purpose you've suggested it for, e.g., like, if(!is_numeric($input)) { error(); } else { return (int)$input; } …you'll parse a lot of strings that still aren't valid integers. (E.g., "2e-2" is "numeric" and would thus parse.)