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/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 13 days ago

Test name	Executions per second
Array clone with spread operator	24496918.0 Ops/sec
Array clone with slice	123318128.0 Ops/sec
Array addition with spread operator	21418496.0 Ops/sec
Array addition with slice and push	27682086.0 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);

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

Array clone with spread operator

Array clone with slice

Array addition with spread operator

Array addition with slice and push