Run results for: Object filtering by key v2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Edg/134.0.0.0

Browser: Chrome 134

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

for-of (object)

4K/s

Reduce (object)

4K/s

Reduce (Map)

3K/s

for-of (Map)

1K/s

View exact numbers

Test name	Executions per second
✓ for-of (object)	4,239 Ops/sec
Reduce (object)	4,154 Ops/sec
Reduce (Map)	2,770 Ops/sec
for-of (Map)	1,311 Ops/sec

Script Preparation code:

var data = { ...Array.from(Array(10000).keys()) };

const filterWithObject = (val) => {
  const result = {}
  for (const key in val) {
    if (Number(key) % 2 === 0) {
      continue;
    }
    result[key] = val[key];
  } 

  return result;
};

const filterWithMap = (val) => {
  const result = new Map();
  for (const key in val) {
    if (Number(key) % 2 === 0) {
      continue;
    }
    result.set(key, val[key]);
  } 

  return Object.fromEntries(result.entries());
};

Tests:

Reduce (object)
Object.keys(data) .filter(key => Number(key) % 2 === 0) .reduce((acc, key) => { acc[key] = data[key]; return acc; }, {});
Reduce (Map)
Object.keys(data) .filter(key => Number(key) % 2 === 0) .reduce((acc, key) => { acc.set(key, data[key]); return acc; }, new Map());
for-of (object)
filterWithObject(data)
for-of (Map)
filterWithMap(data)

Run results for: Object filtering by key v2

Compares different way to filter object

Reduce (object)

Reduce (Map)

for-of (object)

for-of (Map)