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/86.0.4240.193 Safari/537.36

Browser: Chrome 86

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Array clone with spread operator	13020896.0 Ops/sec
Array clone with slice	14970861.0 Ops/sec
Array addition with spread operator	5314723.0 Ops/sec
Array addition with slice and push	5188541.5 Ops/sec
Array removal with spread operator	3268775.0 Ops/sec
Array removal with slice and splice	6220190.5 Ops/sec
Array update with spread operator	2308135.8 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