Integer? Maybe. This has been done over and over, but it's still annoying as hell.

gistfile1.php

<?php

int 12345
string '12345'

filter_var(12345, FILTER_VALIDATE_INT); // true
filter_var('12456', FILTER_VALIDATE_INT); // true

'this is a string'
'12345'
'1' + 1 // 2

1 == 1 // true
'1' == 1 // true
'1' === 1 // false

date('N', $date) // string '7'
date('N', $date) === 7 // false
(int) date('N', $date) === 7 // true