Run results for: for-in vs object.keys vs object.values for objects

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/131.0 Mobile/15E148 Safari/605.1.15

Browser: Mobile Safari 18

Operating system: iOS 18.0

Device Platform: Mobile

Date tested: one year ago

for-in

18/s

Object.values

15/s

Object.keys

15/s

View exact numbers

Test name	Executions per second
✓ for-in	18 Ops/sec
Object.values	15 Ops/sec
Object.keys	15 Ops/sec

Script Preparation code:

var obj = {
  'a': {
    id: 'a',
    num: 1
  },
  'b': {
    id: 'b',
    num: 1
  },
  'c': {
    id: 'c',
    num: 1
  },
  'd': {
    id: 'd',
    num: 1
  },
  'e': {
    id: 'e',
    num: 1
  },
  'f': {
    id: 'f',
    num: 1
  },
  'g': {
    id: 'g',
    num: 1
  },
};

Tests:

for-in
for (var i=10000; i > 0; i--) { for (var key in obj) { console.log(obj[key].id); } }
Object.keys
for (var i=10000; i > 0; i--) { Object.keys(obj).forEach(key => console.log(obj[key].id)); }
Object.values
for (var i=10000; i > 0; i--) { Object.values(obj).forEach(n => console.log(n.id)); }