PHP 8.2 Released

4 min read Original article ↗

Readonly classes RFC Doc

PHP < 8.2

class BlogData
{
    public readonly string $title;

    public readonly Status $status;

    public function __construct(string $title, Status $status)
    {
        $this->title = $title;
        $this->status = $status;
    }
}

PHP 8.2

readonly class BlogData
{
    public string $title;

    public Status $status;

    public function __construct(string $title, Status $status)
    {
        $this->title = $title;
        $this->status = $status;
    }
}

Disjunctive Normal Form (DNF) Types RFC Doc

PHP < 8.2

class Foo {
    public function bar(mixed $entity) {
        if ((($entity instanceof A) && ($entity instanceof B)) || ($entity === null)) {
            return $entity;
        }

        throw new Exception('Invalid entity');
    }
}

PHP 8.2

class Foo {
    public function bar((A&B)|null $entity) {
        return $entity;
    }
}

DNF types allow us to combine union and intersection types, following a strict rule: when combining union and intersection types, intersection types must be grouped with brackets.

Allow null, false, and true as stand-alone types RFC RFC

PHP < 8.2

class Falsy
{
    public function almostFalse(): bool { /* ... */ *}

    public function almostTrue(): bool { /* ... */ *}

    public function almostNull(): string|null { /* ... */ *}
}

PHP 8.2

class Falsy
{
    public function alwaysFalse(): false { /* ... */ *}

    public function alwaysTrue(): true { /* ... */ *}

    public function alwaysNull(): null { /* ... */ *}
}

New "Random" extension RFC RFC Doc

PHP 8.2

use Random\Engine\Xoshiro256StarStar;
use Random\Randomizer;

$blueprintRng = new Xoshiro256StarStar(
    hash('sha256', "Example seed that is converted to a 256 Bit string via SHA-256", true)
);

$fibers = [];
for ($i = 0; $i < 8; $i++) {
    $fiberRng = clone $blueprintRng;
    // Xoshiro256**'s 'jump()' method moves the blueprint ahead 2**128 steps, as if calling
    // 'generate()' 2**128 times, giving the Fiber 2**128 unique values without needing to reseed.
    $blueprintRng->jump();

    $fibers[] = new Fiber(function () use ($fiberRng, $i): void {
        $randomizer = new Randomizer($fiberRng);

        echo "{$i}: " . $randomizer->getInt(0, 100), PHP_EOL;
    });
}

// The randomizer will use a CSPRNG by default.
$randomizer = new Randomizer();

// Even though the fibers execute in a random order, they will print the same value
// each time, because each has its own unique instance of the RNG.
$fibers = $randomizer->shuffleArray($fibers);
foreach ($fibers as $fiber) {
    $fiber->start();
}

The "random" extension provides a new object-oriented API to random number generation. Instead of relying on a globally seeded random number generator (RNG) using the Mersenne Twister algorithm the object-oriented API provides several classes ("Engine"s) providing access to modern algorithms that store their state within objects to allow for multiple independent seedable sequences.

The \Random\Randomizer class provides a high level interface to use the engine's randomness to generate a random integer, to shuffle an array or string, to select random array keys and more.

Constants in traits RFC Doc

PHP 8.2

trait Foo
{
    public const CONSTANT = 1;
}

class Bar
{
    use Foo;
}

var_dump(Bar::CONSTANT); // 1
var_dump(Foo::CONSTANT); // Error

You cannot access the constant through the name of the trait, but, you can access the constant through the class that uses the trait.

Deprecate dynamic properties RFC Doc

PHP < 8.2

class User
{
    public $name;
}

$user = new User();
$user->last_name = 'Doe';

$user = new stdClass();
$user->last_name = 'Doe';

PHP 8.2

class User
{
    public $name;
}

$user = new User();
$user->last_name = 'Doe'; // Deprecated notice

$user = new stdClass();
$user->last_name = 'Doe'; // Still allowed

The creation of dynamic properties is deprecated to help avoid mistakes and typos, unless the class opts in by using the #[\AllowDynamicProperties] attribute. stdClass allows dynamic properties.

Usage of the __get/__set magic methods is not affected by this change.

New Classes, Interfaces, and Functions

Deprecations and backward compatibility breaks