CODE EXAMPLE FOR PHP

laravel reduce

$collection = collect([1, 2, 3]);

$total = $collection->reduce(function ($carry, $item) {
    return $carry + $item;
});

// 6

$total = $collection->reduce(function ($carry, $item) {
    return $carry + $item;
}, 4);

// 10   | where 4 is a initial value