Run results for: Object.keys vs for...in with more items

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:83.0) Gecko/20100101 Firefox/83.0

Browser: Firefox 83

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Object.keys	81.6 Ops/sec
for...in	79.8 Ops/sec

Script Preparation code:

var users = {};
for (var i = 0; i < 1000; i++) {
  users[`user${i}`] = {
    name: `John${i}`,
    age: Math.ceil(Math.random() * 100)
  };
}

Tests:

Object.keys
Object.keys(users).forEach(userId => console.log(users[userId]));
for...in
for (const userId in users) { if (users.hasOwnProperty(userId)) { console.log(users[userId]) } }