Run results for: JavaScript spread operator vs Slice/Splice performance - 2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser: Chrome 117

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Array clone with slice

15.5M/s

Array clone with spread operator

13.6M/s

Array addition with spread operator

5.2M/s

Array addition with slice and push

5.0M/s

View exact numbers

Test name	Executions per second
✓ Array clone with slice	15,515,100 Ops/sec
Array clone with spread operator	13,599,670 Ops/sec
Array addition with spread operator	5,223,594 Ops/sec
Array addition with slice and push	4,973,084 Ops/sec

Script Preparation code:

const ITERATIONS = 500000;
var index = ITERATIONS/2;
var n = Math.random();

var list = [];
for (let i = 0; i < length; i += 1) {
  list.push(Math.random());
}

Tests:

Array clone with spread operator
const clone = [...list];
Array clone with slice
const clone = list.slice();
Array addition with spread operator
const clone = [...list, n];
Array addition with slice and push
const clone = list.slice(); clone.push(n);