Run results for: Map creation alternatives

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser: Chrome 133

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

reduce

631K/s

map

413K/s

for...of

87K/s

View exact numbers

Test name	Executions per second
✓ reduce	631,250 Ops/sec
map	413,061 Ops/sec
for...of	87,463 Ops/sec

Script Preparation code:

function generateAnArray(gvv) {
    let arr = [];
    for(let i = 0; i < 100; i++) {
        arr.push({
            id: i,
            value: `value${i}`
        });
    }
    return arr;
}

xs = generateAnArray();

Tests:

map
let m1 = new Map(xs.map((x) => [x.id, x]));
reduce
let m2 = xs.reduce((map, x) => map.set(x.id, x), new Map())
for...of
let m3 = new Map() for (x of xs) { m3.set(x.id, x) }