Hari 21: Readonly, Fibers & PHP 8.3

Readonly Properties (PHP 8.1)

class Point {
    public function __construct(
        public readonly float $x,
        public readonly float $y,
    ) {}
}

$p = new Point(3.0, 4.0);
echo $p->x; // 3
// $p->x = 5; // Error: Cannot modify readonly property

Readonly Class (PHP 8.2)

readonly class Koordinat {
    public function __construct(
        public float $lat,
        public float $lng,
    ) {}

    public function jarak(Koordinat $other): float {
        return sqrt(($this->lat - $other->lat) ** 2 + ($this->lng - $other->lng) ** 2);
    }
}

$a = new Koordinat(-6.2, 106.8); // Jakarta
$b = new Koordinat(-7.8, 110.4); // Yogyakarta
echo round($a->jarak($b), 2);    // 3.97 (unit derajat)

First-class Callable (PHP 8.1)

// Sebelum: closure wrapper
$strlen  = Closure::fromCallable("strlen");
// Sekarang: langsung dengan ...
$strlen  = strlen(...);
$strtoup = strtoupper(...);

$kata = ["hello", "world", "php"];
$panjang = array_map($strlen, $kata);  // [5, 5, 3]
$upper   = array_map($strtoup, $kata); // ["HELLO","WORLD","PHP"]