Run results for: forEach vs reduce vs for - fill object

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:108.0) Gecko/20100101 Firefox/108.0

Browser: Firefox 108

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Script Preparation code:

var arr = [];
for (var i = 0; i < 20000; i++) {
  arr.push(i);
}

Tests:

forEach
var objForEach = {}; arr.forEach(item => objForEach[item] = true);
reduce
var objReduce = arr.reduce((acc, item) => { acc[item] = true; return acc; }, {});
for
var objFor = {}; for (var j = 0; j < arr.length; j++) { objFor[arr[j]] = true; }