How to update cart with if clause?

[Brecht272727]

Hi,

I am looking for a solution where i can update the cart with p.e. product.id and product.sizeId
But the code below is not working.

var winkelwagen = cartLS.list();
var id = 2;
var size = 4;
var new_qty = 100;

for (var i = 0; i < winkelwagen.length; i++) {
    if (winkelwagen[i].id === id && winkelwagen[i].sizeId === size) {
        winkelwagen[i].quantity = new_qty;
        break;
    }
}

// Update the cart
cartLS.update(winkelwagen);

The problem is that i have p.e. 2 products with the same ID but with different sizeId. So both were updated what is not correct of course.