Run results for: JavaScript spread operator vs Slice/Splice performance, passing

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	24693186.0 Ops/sec
Array clone with slice	118929880.0 Ops/sec
Array addition with spread operator	21538724.0 Ops/sec
Array addition with slice and push	28114982.0 Ops/sec
Array removal with spread operator	16770662.0 Ops/sec
Array removal with slice and splice	51222256.0 Ops/sec
Array update with spread operator	15066070.0 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);
Array removal with spread operator
const clone = [ ...list.slice(0, index), ...list.slice(index + 1), ];
Array removal with slice and splice
const clone = list.slice(); clone.splice(index, 1);
Array update with spread operator
const clone = [ ...list.slice(0, index), n, ...list.slice(index + 1), ];

Run results for: JavaScript spread operator vs Slice/Splice performance, passing

Array clone with spread operator

Array clone with slice

Array addition with spread operator

Array addition with slice and push

Array removal with spread operator

Array removal with slice and splice

Array update with spread operator