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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser: Chrome 128

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

`Array.slice(0, N)`

7.1M/s

`Array.length = N`

6.5M/s

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

196K/s

View exact numbers

Test name	Executions per second
✓ `Array.slice(0, N)`	7,147,432 Ops/sec
`Array.length = N`	6,496,310 Ops/sec
`Object.assign([], arr)` with `Array.length = N`	195,703 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;