Fast and slow objects example

memory.js

function FastPurchase (units, price) {
    this.units = units;
    this.price = price;
    this.total = 0;
    this.x = 1;
};

var fast = new FastPurchase(3, 25);
fast.x = null;

function SlowPurchase (units, price) {
    this.units = units;
    this.price = price;
    this.total = 0;
    this.x = 1;
};

var slow = new SlowPurchase(3, 25);
delete slow.x;
// Up to 3 times more memory