Benchmark: Performance of JavaScript .forEach, for in v3

Script Preparation code:

function generateTestArray() {
  const result = [];
  for (let i = 0; i < 1000000; ++i) {
    result.push({
      a: i,
      b: i / 2,
      r: 0,
    });
  }
  return result;
}

Tests:

.forEach destructured
const array = generateTestArray(); const newMap = new Map(); array.forEach(({a, b}) => { newMap.set(a, b); }); const foo = [...newMap.entries()];
for..of destructured
const array = generateTestArray(); const newMap = new Map(); for(const {a, b} of array) { newMap.set(a, b); } const foo = [...newMap.entries()];
.forEach
const array = generateTestArray(); const newMap = new Map(); array.forEach((x) => { const {a, b} = x; newMap.set(a, b); }); const foo = [...newMap.entries()];
for..of
const array = generateTestArray(); const newMap = new Map(); for(const x of array) { const {a, b} = x; newMap.set(a, b); } const foo = [...newMap.entries()];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.forEach destructured
for..of destructured
.forEach
for..of

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/111.0.5563.72 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 111 on iOS 16.3

View result in a separate tab

Test name	Executions per second
.forEach destructured	7.8 Ops/sec
for..of destructured	9.5 Ops/sec
.forEach	7.7 Ops/sec
for..of	10.1 Ops/sec

Performance of JavaScript .forEach, for in v3 (version: 2)

Comparing performance of: .forEach destructured vs for..of destructured vs .forEach vs for..of

Created: one year ago by: Registered User

Jump to the latest result

.forEach destructured

for..of destructured

.forEach

for..of

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A