Type conversion in php

php-fuckery.php

<?php
$a = "";
var_dump(($a == null)); //outputs false
var_dump(($a === null)); //outputs true
var_dump(is_null($a)); //outputs true


$b;
var_dump(($b == null)); //outputs true
var_dump(($b === null)); //outputs true
var_dump(is_null($b)); //outputs true
?>