- substr: documentation ( source)
- var_dump: documentation ( source)
- ctype_digit: documentation ( source)
<?php
$str = "1234kjhgkdfkgjh";
$result = ctype_digit(substr($str, 0, 2));
var_dump($result);
$str2 = ".1234kjhgkdfkgjh";
$result = ctype_digit(substr($str2, 0, 2));
var_dump($result);