Run results for: Object.assign vs for...in...

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.1 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 5 months ago

Object.assign

1.2M/s

For in

1.0M/s

View exact numbers

Test name	Executions per second
✓ Object.assign	1,195,031 Ops/sec
For in	1,001,813 Ops/sec

Script Preparation code:

var target = {};
var obj = {};

for (var i = 0; i < 100; i++) {
	obj['propp'+i] = ('this is a value ' + i);
}

Tests: