Run results for: compare .map with for...of

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.6 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 10 months ago

.map (destructured)

1.9M/s

.map

1.9M/s

for...of

1.7M/s

for...of (destructured)

1.7M/s

for...of [fixedLengthResult]

1.7M/s

for...of (destructured) [fixedLengthResult]

1.7M/s

View exact numbers

Test name	Executions per second
✓ .map (destructured)	1,870,758 Ops/sec
.map	1,869,032 Ops/sec
for...of	1,744,010 Ops/sec
for...of (destructured)	1,713,602 Ops/sec
for...of [fixedLengthResult]	1,703,328 Ops/sec
for...of (destructured) [fixedLengthResult]	1,694,326 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

function generateTestArray() {
  const result = [];
  for (let i = 0; i < 100; ++i) {
    result.push({
      a: i,
      b: i / 2,
    });
  }
  return result;
}

Tests:

.map
const array = generateTestArray(); const result = array.map(x => x.a + x.b);
.map (destructured)
const array = generateTestArray(); const result = array.map(({a,b}) => a + b);
for...of
const array = generateTestArray(); const result = []; for (const x of array) { result.push(x.a + x.b); }
for...of (destructured)
const array = generateTestArray(); const result = []; for (const {a,b} of array) { result.push(a + b); }
for...of [fixedLengthResult]
const array = generateTestArray(); const result = new Array(array.length); for (const x of array) { result.push(x.a + x.b); };
for...of (destructured) [fixedLengthResult]
const array = generateTestArray(); const result = new Array(array.length); for (const {a,b} of array) { result.push(a + b); };