Run results for: Iterate over 2 object with merge 2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Browser: Chrome 69

Operating system: Mac OS X 10.13.6

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
for..in with hasOwnProperty()	88.3 Ops/sec
Object.keys() + Array.forEach()	106.6 Ops/sec

Script Preparation code:

var o1 = {};
var o2 = {};

for(var i=0; i<5000; i++) {
  o1[`id${i}`] = {i};
  o1[`id${i}2`] = {i};
}
const out = {}

var assignIn = (key) => {
    out[key] = {}
    Object.assign(out[key], o1[key], o2[key])
}

Tests:

for..in with hasOwnProperty()
for (const key in o1) { if (o1.hasOwnProperty(key)) { assignIn(key) } } for (const key in o2) { if (o2.hasOwnProperty(key)) { assignIn(key) } }
Object.keys() + Array.forEach()
Object.keys(o1) .concat(Object.keys(o2)) .forEach(assignIn)

Run results for: Iterate over 2 object with merge 2

for..in with hasOwnProperty()

Object.keys() + Array.forEach()