Benchmark: Performance of JavaScript .forEach, .map and .reduce vs for and for..of with 1000p

Script Preparation code:

function generateTestArray() {
  const result = [];
  for (let i = 0; i < 1000; ++i) {
    result.push({
      a: i,
      b: i / 2,
      r: 0,
    });
  }
  return result;
}

Tests:

.forEach
const array = generateTestArray(); array.forEach((x) => { x.r = x.a + x.b; });
for..of
const array = generateTestArray(); for(const x of array) { x.r = x.a + x.b; }
for..of (destructuring)
const array = generateTestArray(); const r = []; for(const {a, b} of array) { r.push(a + b); }
.map
const array = generateTestArray(); array.map(x => x.a + x.b)
.map (destructuring)
const array = generateTestArray(); array.map(({a,b}) => a + b)
.for (init array)
const array = generateTestArray(); const r = new Array(array.length); for (let i = 0; i < array.length; ++i) { r[i] = array[i].a + array[i].b; }
.reduce
const array = generateTestArray(); array.reduce((p, x) => p + x.a + x.b, 0);
.reduce (destructuring)
const array = generateTestArray(); array.reduce((p, {a,b}) => p + a + b, 0);
for..of (reduce)
const array = generateTestArray(); let r = 0; for (const x of array) { r += x.a + x.b; }
for..of (reduce) (destructuring)
const array = generateTestArray(); let r = 0; for (const {a,b} of array) { r += a + b; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.forEach
for..of
for..of (destructuring)
.map
.map (destructuring)
.for (init array)
.reduce
.reduce (destructuring)
for..of (reduce)
for..of (reduce) (destructuring)

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 24 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
.forEach	137823.6 Ops/sec
for..of	144124.4 Ops/sec
for..of (destructuring)	104607.4 Ops/sec
.map	102005.7 Ops/sec
.map (destructuring)	102275.8 Ops/sec
.for (init array)	128094.4 Ops/sec
.reduce	116140.6 Ops/sec
.reduce (destructuring)	115085.3 Ops/sec
for..of (reduce)	149802.0 Ops/sec
for..of (reduce) (destructuring)	149635.4 Ops/sec

Performance of JavaScript .forEach, .map and .reduce vs for and for..of with 1000p (version: 0)

Comparing performance of: .forEach vs for..of vs for..of (destructuring) vs .map vs .map (destructuring) vs .for (init array) vs .reduce vs .reduce (destructuring) vs for..of (reduce) vs for..of (reduce) (destructuring)

Created: 24 days ago by: Guest

Jump to the latest result

.forEach

for..of

for..of (destructuring)

.map

.map (destructuring)

.for (init array)

.reduce

.reduce (destructuring)

for..of (reduce)

for..of (reduce) (destructuring)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A