Validating Integers without Regular Expression in PHP

ctype_digit checks if all of the characters in the provided string are numerical. Therefore, you must convert variables to string first, then you check them with ctype_digit.

$array = array(5, 5.2, "456", "564-223", "5.2", "673");
foreach($array as $item) {
   if(ctype_digit((string)$item)) {
      echo "int: ".$item."\n";
   } else {
      echo "not int: ".$item."\n";
   }
}