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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:79.0) Gecko/20100101 Firefox/79.0

Browser: Firefox 79

Operating system: Mac OS X 10.14

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
`Array.slice(0, N)`	14055436.0 Ops/sec
`Array.length = N`	34888228.0 Ops/sec
`Object.assign([], arr)` with `Array.length = N`	482625.2 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;