1--TEST-- 2Test usort() function : usage variations - use built in functions as $cmp_function arg 3--FILE-- 4<?php 5/* Prototype : bool usort(array $array_arg, string $cmp_function) 6 * Description: Sort an array by values using a user-defined comparison function 7 * Source code: ext/standard/array.c 8 */ 9 10/* 11 * Test usort() when comparison function is: 12 * 1. a built in comparison function 13 * 2. a language construct 14 */ 15 16echo "*** Testing usort() : usage variation ***\n"; 17 18// Initializing variables 19$array_arg = array("b" => "Banana", "m" => "Mango", "a" => "apple", 20 "p" => "Pineapple", "o" => "orange"); 21 22// Testing library functions as comparison function 23echo "\n-- Testing usort() with built-in 'cmp_function': strcasecmp() --\n"; 24$temp_array1 = $array_arg; 25var_dump( usort($temp_array1, 'strcasecmp') ); 26var_dump($temp_array1); 27 28echo "\n-- Testing usort() with built-in 'cmp_function': strcmp() --\n"; 29$temp_array2 = $array_arg; 30var_dump( usort($temp_array2, 'strcmp') ); 31var_dump($temp_array2); 32 33// Testing with language construct as comparison function 34echo "\n-- Testing usort() with language construct as 'cmp_function' --\n"; 35$temp_array3 = $array_arg; 36var_dump( usort($temp_array3, 'echo') ); 37 38echo "\n-- Testing usort() with language construct as 'cmp_function' --\n"; 39$temp_array4 = $array_arg; 40var_dump( usort($temp_array4, 'exit') ); 41?> 42===DONE=== 43--EXPECTF-- 44*** Testing usort() : usage variation *** 45 46-- Testing usort() with built-in 'cmp_function': strcasecmp() -- 47bool(true) 48array(5) { 49 [0]=> 50 string(5) "apple" 51 [1]=> 52 string(6) "Banana" 53 [2]=> 54 string(5) "Mango" 55 [3]=> 56 string(6) "orange" 57 [4]=> 58 string(9) "Pineapple" 59} 60 61-- Testing usort() with built-in 'cmp_function': strcmp() -- 62bool(true) 63array(5) { 64 [0]=> 65 string(6) "Banana" 66 [1]=> 67 string(5) "Mango" 68 [2]=> 69 string(9) "Pineapple" 70 [3]=> 71 string(5) "apple" 72 [4]=> 73 string(6) "orange" 74} 75 76-- Testing usort() with language construct as 'cmp_function' -- 77 78Warning: usort() expects parameter 2 to be a valid callback, function 'echo' not found or invalid function name in %s on line %d 79NULL 80 81-- Testing usort() with language construct as 'cmp_function' -- 82 83Warning: usort() expects parameter 2 to be a valid callback, function 'exit' not found or invalid function name in %s on line %d 84NULL 85===DONE=== 86