Online PHP editor | refs for sQEWm

<?php $a = '0e123'; var_dump($a == 0); var_dump($a == "0"); var_dump($a == 0x0); var_dump($a == true); var_dump($a != ' '); var_dump($a == ""); var_dump($a == ''); echo trim($a) ? 'X' : 'O'; echo empty($a) ? 'X' : 'O'; echo !empty($a) ? 'X' : 'O'; echo -$a ? 'X' : 'O'; echo "\n"; define('0e', 1); var_dump($a == constant('0e')); echo "\n"; var_dump($a == " $a"); var_dump($a == "$a "); var_dump($a == '0x'); var_dump($a == '0e'); echo "\n"; var_dump($a == '0xe'); var_dump($a == '0xe0'); var_dump($a == '0x0e'); var_dump($a == ('0' . 'x0e'));