"Numerieke stringwaarde" Afvang
/**
* This function returns true only when given positive integer or string that contains only digits
* @link http://nl3.php.net/manual/en/function.ctype-digit.php (Comments)
*/
function isDigital($var){
return ($var===0 || $var==='0' || (!empty($var) && (is_string($var) || is_int($var)) && ctype_digit((string) $var)));
}
function isFloat($var){
return ($this->isDigital($var) || is_numeric($var));
}