1--TEST-- 2casting different variables to null using settype() 3--FILE-- 4<?php 5 6$r = fopen(__FILE__, "r"); 7 8class test { 9 function __toString() { 10 return "10"; 11 } 12} 13 14$o = new test; 15 16$vars = array( 17 "string", 18 "8754456", 19 "", 20 "\0", 21 9876545, 22 0.10, 23 array(), 24 array(1,2,3), 25 false, 26 true, 27 NULL, 28 $r, 29 $o 30); 31 32foreach ($vars as $var) { 33 settype($var, "null"); 34 var_dump($var); 35} 36 37echo "Done\n"; 38?> 39--EXPECTF-- 40NULL 41NULL 42NULL 43NULL 44NULL 45NULL 46NULL 47NULL 48NULL 49NULL 50NULL 51NULL 52NULL 53Done 54