--TEST-- Test usort() function : usage variations - use built in functions as $cmp_function arg --FILE-- "Banana", "m" => "Mango", "a" => "apple", "p" => "Pineapple", "o" => "orange"); // Testing library functions as comparison function echo "\n-- Testing usort() with built-in 'cmp_function': strcasecmp() --\n"; $temp_array1 = $array_arg; var_dump( usort($temp_array1, 'strcasecmp') ); var_dump($temp_array1); echo "\n-- Testing usort() with built-in 'cmp_function': strcmp() --\n"; $temp_array2 = $array_arg; var_dump( usort($temp_array2, 'strcmp') ); var_dump($temp_array2); ?> --EXPECT-- *** Testing usort() : usage variation *** -- Testing usort() with built-in 'cmp_function': strcasecmp() -- bool(true) array(5) { [0]=> string(5) "apple" [1]=> string(6) "Banana" [2]=> string(5) "Mango" [3]=> string(6) "orange" [4]=> string(9) "Pineapple" } -- Testing usort() with built-in 'cmp_function': strcmp() -- bool(true) array(5) { [0]=> string(6) "Banana" [1]=> string(5) "Mango" [2]=> string(9) "Pineapple" [3]=> string(5) "apple" [4]=> string(6) "orange" }