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