all()

/**
 * @throws Throwable
 * @param array<int, Async|Promise|callable> $promises
 * @phpstan-param array<int, Async|Promise|callable> $promises
 */
public static function all(array $promises): Promise;

The Promise::all() static method takes an iterable of promises as input and returns a single Promise. This returned promise fulfills when all of the input's promises fulfill (including when an empty iterable is passed), with an array of the fulfillment values. It rejects when any of the input's promises rejects, with this first rejection reason.

Example:

function testPromise1() : Promise { 
    return new Promise(function ($resolve, $reject) {
        $resolve("A");
    });
}

function testPromise2() : Promise {
    return new Promise(function ($resolve, $reject) {
        $reject("B");
    });
}

Promise::all([
	testPromise1(),
	testPromise2()
])->then(fn($result) => var_dump($promise));

Output:

Array ["A", "B"]