Enumerations
// PHP < 8.1
class Status
{
const DRAFT = 'draft';
const PUBLISHED = 'published';
const ARCHIVED = 'archived';
}
function acceptStatus(string $status) {...}
// PHP 8.1
enum Status
{
case Draft;
case Published;
case Archived;
}
function acceptStatus(Status $status) {...}
Readonly Properties
// PHP < 8.1
class BlogData
{
private Status $status;
public function __construct(Status $status)
{
$this->status = $status;
}
public function getStatus(): Status
{
return $this->status;
}
}
// PHP 8.1
class BlogData
{
public readonly Status $status;
public function __construct(Status $status)
{
$this->status = $status;
}
}
First-class Callable Syntax
// PHP < 8.1
$foo = [$this, 'foo'];
$fn = Closure::fromCallable('strlen');
// PHP 8.1
$foo = $this->foo(...);
$fn = strlen(...);
New in initializers
// PHP < 8.1
class Service
{
private Logger $logger;
public function __construct(
?Logger $logger = null,
) {
$this->logger = $logger ?? new NullLogger();
}
}
// PHP 8.1
class Service
{
private Logger $logger;
public function __construct(
Logger $logger = new NullLogger(),
) {
$this->logger = $logger;
}
}
Pure Intersection Types
// PHP < 8.1
function count_and_iterate(Iterator $value) {
if (!($value instanceof Countable)) {
throw new TypeError('value must be Countable');
}
foreach ($value as $val) {
echo $val;
}
count($value);
}
// PHP 8.1
function count_and_iterate(Iterator&Countable $value) {
foreach ($value as $val) {
echo $val;
}
count($value);
}
Never return type
// PHP < 8.1
function redirect(string $uri) {
header('Location: ' . $uri);
exit();
}
function redirectToLoginPage() {
redirect('/login');
echo 'Hello'; // <- dead code
}
// PHP 8.1
function redirect(string $uri): never {
header('Location: ' . $uri);
exit();
}
function redirectToLoginPage(): never {
redirect('/login');
echo 'Hello'; // <- dead code detected by static analysis
}
Final class constants
// PHP < 8.1
class Foo
{
public const XX = "foo";
}
class Bar extends Foo
{
public const XX = "bar"; // No error
}
// PHP 8.1
class Foo
{
final public const XX = "foo";
}
class Bar extends Foo
{
public const XX = "bar"; // Fatal error
}
Explicit Octal numeral notation
// PHP < 8.1
016 === 16; // false because `016` is octal for `14` and it's confusing
016 === 14; // true
// PHP 8.1
0o16 === 16; // false — not confusing with explicit notation
0o16 === 14; // true
Fibers
// PHP < 8.1
$httpClient->request('https://example.com/')
->then(function (Response $response) {
return $response->getBody()->buffer();
})
->then(function (string $responseBody) {
print json_decode($responseBody)['code'];
});
// PHP 8.1
$response = $httpClient->request('https://example.com/');
print json_decode($response->getBody()->buffer())['code'];
Array unpacking support for string-keyed arrays
// PHP < 8.1
$arrayA = ['a' => 1];
$arrayB = ['b' => 2];
$result = array_merge(['a' => 0], $arrayA, $arrayB);
// ['a' => 1, 'b' => 2]
// PHP 8.1
$arrayA = ['a' => 1];
$arrayB = ['b' => 2];
$result = ['a' => 0, ...$arrayA, ...$arrayB];
// ['a' => 1, 'b' => 2]