Run results for: forEach vs for ... of

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36 OPR/109.0.0.0 (Edition Yx 05)

Browser: Opera 109

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

for of

16/s

forEach

14/s

View exact numbers

Test name	Executions per second
✓ for of	16 Ops/sec
forEach	14 Ops/sec

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
const a = generateTestArray(); a.forEach( b => b*2 );
for of
const a = generateTestArray(); for ( let b of a) { b=b*2; }