cpucache-perf.js

function prepare(n) {
    const arr = [];
    for (let i = 0; i < n; i++) {
        arr[i] = {a: i % 2 === 0 ? -i : i, b: {h: {x: i}, c: {i: i, d: {e: {e: {u: {x: i}}}}}}};
    }
    shuffleArray(arr);
    return arr;
}
function shuffleArray(array) {
    for (var i = array.length - 1; i > 0; i--) {
        var j = Math.floor(Math.random() * (i + 1));
        var temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
}

function foo(arr) {
    let s = 0;
    for (let i = 0; i < arr.length; i++) {
        s += arr[i].a;
    }
    return s;
}

const arr = prepare(1e7);
console.time('perf');
let x = foo(arr);
console.timeEnd('perf');
console.log(process.memoryUsage(), x, arr);