Run results for: `Array.slice(0, N)` vs `Array.length = N`

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser: Chrome 115

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

`Array.slice(0, N)`

11.3M/s

`Array.length = N`

10.9M/s

`Object.assign([], arr)` with `Array.length = N`

292K/s

View exact numbers

Test name	Executions per second
✓ `Array.slice(0, N)`	11,259,174 Ops/sec
`Array.length = N`	10,930,958 Ops/sec
`Object.assign([], arr)` with `Array.length = N`	292,312 Ops/sec

Script Preparation code:

var arr = Array.from(Array(100).keys());

Tests:

`Array.slice(0, N)`
arr.slice(0, 20);
`Array.length = N`
arr.length = 20;
`Object.assign([], arr)` with `Array.length = N`
var newArr = Object.assign([], arr); newArr.length = 20;