Array of PHP Objects

The best place to find answers to general (and somewhat easy questions) such as this is to read up on PHP docs. Specifically in your case you can read more on objects. You can store stdObject and instantiated objects within an array. In fact, there is a process known as 'hydration' which populates the member variables of an object with values from a database row, then the object is stored in an array (possibly with other objects) and returned to the calling code for access.

-- Edit --

class Car
{
    public $color;
    public $type;
}

$myCar = new Car();
$myCar->color = 'red';
$myCar->type = 'sedan';

$yourCar = new Car();
$yourCar->color = 'blue';
$yourCar->type = 'suv';

$cars = array($myCar, $yourCar);

foreach ($cars as $car) {
    echo 'This car is a ' . $car->color . ' ' . $car->type . "n";
}

As order of values in array returned by Object.values() isn't guaranteed, you should consider use of .map() with some Object Destructuring. You can then extract object properties in separate variables and return them in desired order explicitly.

const data = [
  { amount: '100', user: 'admin', date: 'March 6, 2019' },
  { amount: '120', user: 'admin', date: 'March 6, 2019' },
  { amount: '80',  user: 'admin', date: 'March 7, 2019' },
  { amount: '200', user: 'admin', date: 'March 7, 2019' }
];

const result = data.map(({ amount, user, date }) => [amount, user, date]);

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

function benchmark($func_name, $iterations) {
    $begin = microtime(true);
    for ($i = 0; $i < $iterations; $i++) {
        $func_name();
    }
    $end = microtime(true);

    $execution_time = $end - $begin;

    echo $func_name , ': ' , $execution_time;
}

function standClass() {
    $obj = new stdClass();
    $obj->param_one = 1;
    $obj->param_two = 2;
}

function castFromArray() {
    $obj = (object)array('param_one' => 1, 'param_two' => 2);
}


benchmark('standClass', 1000);
benchmark('castFromArray', 1000);

benchmark('standClass', 100000);
benchmark('castFromArray', 100000);

Outputs:

standClass: 0.0045979022979736
castFromArray: 0.0053138732910156

standClass: 0.27266097068787
castFromArray: 0.20209217071533

Casting from an array to stdClass on the fly is around 30% more efficient, but the difference is still negligible until you know you will be performing the operation 100,000 times (and even then, you're only looking at a tenth of a second, at least on my machine).

So, in short, it doesn't really matter the vast majority of the time, but if it does, define the array in a single command and then type-cast it to an object. I definitely wouldn't spend time worrying about it unless you've identified the code in question as a bottleneck (and even then, focus on reducing your number of iterations if possible).