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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser: Chrome 122

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Array.prototype.slice [direct call]

7.8M/s

Spread operator

7.6M/s

Array.prototype.concat [direct call]

4.4M/s

Array.prototype.slice [saved function call]

4.2M/s

Array.prototype.concat [saved function call]

3.0M/s

View exact numbers

Test name	Executions per second
✓ Array.prototype.slice [direct call]	7,769,741 Ops/sec
Spread operator	7,553,113 Ops/sec
Array.prototype.concat [direct call]	4,375,342 Ops/sec
Array.prototype.slice [saved function call]	4,201,130 Ops/sec
Array.prototype.concat [saved function call]	3,009,979 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];