1--TEST-- 2Test array_diff_ukey() function : usage variation - Passing non-existing function name to callback 3--FILE-- 4<?php 5/* Prototype : array array_diff_ukey(array arr1, array arr2 [, array ...], callback key_comp_func) 6 * Description: Returns the entries of arr1 that have keys which are not present in any of the others arguments. 7 * Source code: ext/standard/array.c 8 */ 9 10echo "*** Testing array_diff_ukey() : usage variation ***\n"; 11 12//Initialize variables 13$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red"); 14$array2 = array("a" => "green", "yellow", "red"); 15 16//function name within double quotes 17var_dump( array_diff_ukey($array1, $array1, "unknown_function") ); 18 19//function name within single quotes 20var_dump( array_diff_ukey($array1, $array1, 'unknown_function') ); 21 22//function name without quotes 23var_dump( array_diff_ukey($array1, $array1, unknown_function) ); 24 25?> 26===DONE=== 27--EXPECTF-- 28*** Testing array_diff_ukey() : usage variation *** 29 30Warning: array_diff_ukey() expects parameter 3 to be a valid callback, function 'unknown_function' not found or invalid function name in %s on line %d 31NULL 32 33Warning: array_diff_ukey() expects parameter 3 to be a valid callback, function 'unknown_function' not found or invalid function name in %s on line %d 34NULL 35 36Notice: Use of undefined constant unknown_function - assumed 'unknown_function' in %s on line %d 37 38Warning: array_diff_ukey() expects parameter 3 to be a valid callback, function 'unknown_function' not found or invalid function name in %s on line %d 39NULL 40===DONE=== 41