Run results for: MapFilter vs ForEach

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.167 Safari/537.36

Browser: Chrome 64

Operating system: Mac OS X 10.13.3

Device Platform: Other

Date tested: 2025 years ago

Test name	Executions per second
ForEach	109385.0 Ops/sec
MapFilter	95377.7 Ops/sec

Script Preparation code:

function guid() {
  function s4() {
    return Math.floor((1 + Math.random()) * 0x10000)
      .toString(16)
      .substring(1);
  }
  return s4() + s4() + '-' + s4() + '-' + s4() + '-' + s4() + '-' + s4() + s4() + s4();
}

arr = [];
for (let i = 0; i < 1000; i++) {
  arr[i] = { id: i, value: guid() }
}

Tests:

ForEach
let result = []; arr.forEach(e => { if (e.id % 7 === 0 || e.id % 13 === 2) { result.push({ text: 'id: ' + e.value, value: e.id }); } });
MapFilter
result = arr.filter(e => e.id % 7 === 0 || e.id % 13 === 2).map(e => ({ text: 'id: ' + e.value, value: e.id }))