Benchmark: Splice vs Spread vs Unshift to insert at beginning of array vs manual

Script Preparation code:

var array = Array.from({ length: 100 }).map((val, i) => i);

Tests:

Splice
var newArray = array.slice(0, 0, 99);
Spread
var newArray = [99, ...array];
Unshift
var newArray = array.unshift(99);
manual
var len=array.length, item=99; while (len) { array[len] = array[len-1]; len--} array[0] = item;

Rendered benchmark preparation results:

Previous results

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Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:104.0) Gecko/20100101 Firefox/104.0

Browser/OS: Firefox 104 on Windows

Splice vs Spread vs Unshift to insert at beginning of array vs manual (version: 0)