Run results for: For in vs Object.keys.forEach vs For of Object.keys

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.55 Safari/537.36

Browser: Chrome 96

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Script Preparation code:

var obj = new Object()
var keys = (new Array(100)).fill(0).map((x, i) => {
    return i + 1
})
keys.forEach((x) => {
    obj['prop' + x] = x
})

Tests:

for in
for (var key in obj) { if (obj.hasOwnProperty(key)) console.log(obj[key]) }
for each
Object.keys(obj).forEach(key => console.log(obj[key]))
for of
for (const key of Object.keys(obj)) { console.log(obj[key]) }
for of (outside const)
const keys = Object.keys(obj) for (const key of keys) { console.log(obj[key]) }