Run results for: Array.slice vs Array.concat vs Spread operator

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 Edg/87.0.664.41

Browser: Chrome 87

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Array.prototype.slice [direct call]	1928976.4 Ops/sec
Array.prototype.slice [saved function call]	975886.4 Ops/sec
Array.prototype.concat [direct call]	1163678.8 Ops/sec
Array.prototype.concat [saved function call]	706708.4 Ops/sec
Spread operator	1392730.0 Ops/sec

Script Preparation code:

window.testArray = [1, 'a', undefined, null, false, { a: 123 }, [1, 2, 3]];
window.arraySlice = Array.prototype.slice;
window.arrayConcat = Array.prototype.concat;

Tests:

Array.prototype.slice [direct call]
const a = window.testArray.slice();
Array.prototype.slice [saved function call]
const a = arraySlice.call(window.testArray);
Array.prototype.concat [direct call]
const a = window.testArray.concat([]);
Array.prototype.concat [saved function call]
const a = window.arrayConcat.call(window.testArray, []);
Spread operator
const a = [...window.testArray];

Run results for: Array.slice vs Array.concat vs Spread operator

Array.prototype.slice [direct call]

Array.prototype.slice [saved function call]

Array.prototype.concat [direct call]

Array.prototype.concat [saved function call]

Spread operator