Performance test between forEach and for of

test.js

function runTest_ForEach(a, b) {

    const start = performance.now();
    a.forEach(v => {
        b.push(v  * 2);
    });
    return performance.now() - start;
}

function runTest_ForOf(a, b) {

    const start = performance.now();
    for (const v of a) {
        b.push(v  * 2);
    }
    return performance.now() - start;
}

console.log("Creating Array");
const a = [];
for (let i = 0; i < 10000000; i++) {
    a.push( Math.random() );
}

const testRuns = 50;
const p25 = testRuns / 4;
const p50 = testRuns / 2;
const p75 = 3 * testRuns / 4;
const p100 = testRuns - 1;

let totalTime = 0;
console.log('Running For Each Tests');
for (let i = 0; i < testRuns; i++) {
    totalTime += runTest_ForEach(a, []);
    if (i === 0) console.log('0%');
    if (i === p25) console.log('25%');
    if (i === p50) console.log('50%');
    if (i === p75) console.log('75%');
    if (i === p100) console.log('100%');
}
console.log(`Average Time For Each: ${totalTime / 100}`);

totalTime = 0;
console.log('Running For Of Tests');
for (let i = 0; i < testRuns; i++) {
    totalTime += runTest_ForOf(a, []);
    if (i === 0) console.log('0%');
    if (i === p25) console.log('25%');
    if (i === p50) console.log('50%');
    if (i === p75) console.log('75%');
    if (i === p100) console.log('100%');
}
console.log(`Average Time For Of: ${totalTime / 100}`);