PHP 8.1 发布：新增枚举功能

class Status{    const DRAFT = 'draft';    const PUBLISHED = 'published';    const ARCHIVED = 'archived';}function acceptStatus(string $status) {...}

enum Status{    case Draft;    case Published;    case Archived;}function acceptStatus(Status $status) {...}

class BlogData{    private Status $status;      public function __construct(Status $status)    {        $this->status = $status;    }       public function getStatus(): Status    {        return $this->status;       }}

class BlogData{    public readonly Status $status;      public function __construct(Status $status)    {        $this->status = $status;    }}

$foo = [$this, 'foo'];
$fn = Closure::fromCallable('strlen');

$foo = $this->foo(...);
$fn = strlen(...);

class Service{    private Logger $logger;
    public function __construct(        ?Logger $logger = null,    ) {        $this->logger = $logger ?? new NullLogger();    }}

class Service{    private Logger $logger;       public function __construct(        Logger $logger = new NullLogger(),    ) {        $this->logger = $logger;    }}

class User{    /**     * @Assert\All({     *     @Assert\NotNull,     *     @Assert\Length(min=5)     * })     */    public string $name = '';}

class User{    #[\Assert\All(        new \Assert\NotNull,        new \Assert\Length(min: 6))    ]    public string $name = '';}

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);}

function count_and_iterate(Iterator&Countable $value) {    foreach ($value as $val) {        echo $val;    }
    count($value);}

function redirect(string $uri) {    header('Location: ' . $uri);    exit();}
function redirectToLoginPage() {    redirect('/login');    echo 'Hello'; // <- dead code}

function redirect(string $uri): never {    header('Location: ' . $uri);    exit();}
function redirectToLoginPage(): never {    redirect('/login');    echo 'Hello'; // <- dead code detected by static analysis}

class Foo{    public const XX = "foo";}
class Bar extends Foo{    public const XX = "bar"; // No error}

class Foo{    final public const XX = "foo";}
class Bar extends Foo{    public const XX = "bar"; // Fatal error}

016 === 16; // false because `016` is octal for `14` and it's confusing016 === 14; // true

016 === 16; // false because `016` is octal for `14` and it's confusing016 === 14; // true

$httpClient->request('https://example.com/')        ->then(function (Response $response) {            return $response->getBody()->buffer();        })        ->then(function (string $responseBody) {            print json_decode($responseBody)['code'];        });

$response = $httpClient->request('https://example.com/');print json_decode($response->getBody()->buffer())['code'];

$arrayA = ['a' => 1];$arrayB = ['b' => 2];
$result = array_merge(['a' => 0], $arrayA, $arrayB);
// ['a' => 1, 'b' => 2]

$arrayA = ['a' => 1];$arrayB = ['b' => 2];
$result = ['a' => 0, ...$arrayA, ...$arrayB];
// ['a' => 1, 'b' => 2]