--TEST-- Test array_flip() function : usage variations - 'input' array with different keys --FILE-- 'int_key', // expected: value will be replaced by 'bool_key1' -2 => 'negative_key', 012 => 'octal_key', 0x34 => 'hex_key', // string keys 'key' => 'string_key1', "two" => 'string_key2', '' => 'string_key3', "" => 'string_key4', " " => 'string_key5', // bool keys true => 'bool_key1', false => 'bool_key2', // binary key "a".chr(0)."b" => 'binary_key1', b"binary" => 'binary_key2', ); var_dump( array_flip($input) ); echo "Done" ?> --EXPECTF-- *** Testing array_flip() : different keys for 'input' array argument *** array(11) { ["bool_key2"]=> int(0) ["bool_key1"]=> int(1) ["negative_key"]=> int(-2) ["octal_key"]=> int(10) ["hex_key"]=> int(52) ["string_key1"]=> string(3) "key" ["string_key2"]=> string(3) "two" ["string_key4"]=> string(0) "" ["string_key5"]=> string(1) " " ["binary_key1"]=> string(3) "a%0b" ["binary_key2"]=> string(6) "binary" } Done