Run results for: for let vs Object.keys 3

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser: Chrome 125

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Object.keys

5K/s

for let i in

5K/s

Object.keys (cached)

4K/s

View exact numbers

Test name	Executions per second
✓ Object.keys	5,172 Ops/sec
for let i in	5,106 Ops/sec
Object.keys (cached)	3,609 Ops/sec

Script Preparation code:

var myObject = {};
var sum = 0;

for (let i = 0; i < 1000; i++)
    myObject["property_" + Math.random()] = Math.random();

var keys = Object.keys(myObject);

Tests:

Object.keys
sum = 0; const newKeys = Object.keys (myObject); for (let i = 0 ; i < newKeys.length ; i++) sum += myObject[newKeys[i]];
Object.keys (cached)
sum = 0; for (let i = 0 ; i < keys.length ; i++) sum += myObject[keys[i]];
for let i in
sum = 0; for (let i in myObject) sum += myObject[i];