<?php
echo "\nChecking NULL: ";
var_dump( NULL == '*');

echo "\nChecking 0: ";
var_dump( 0 == '*');

echo "\nChecking 1: ";
var_dump( 1 == '*');

echo "\nChecking '0': ";
var_dump( '0' == '*');

echo "\nChecking '1': ";
var_dump( '1' == '*');