Run results for: for of vs flatmap vs reduce 2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser: Chrome 125

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

reduce

80/s

for of

75/s

flatMap

20/s

View exact numbers

Test name	Executions per second
✓ reduce	80 Ops/sec
for of	75 Ops/sec
flatMap	20 Ops/sec

Script Preparation code:

var data = [];
for (let i = 0; i < 100; i++) {
    const items = [];
    for (let j = 0; j < 100; j++) {
        const innerItems = [];

        for (let k = 0; k < 100; k++) {
            innerItems.push({
                value: k
            });
        }
        items.push({
            innerItems
        });
    }
    data.push({
        items
    });
}

Tests:

flatMap
const result2 = data .flatMap((outer) => outer.items) .flatMap((inner) => inner.innerItems) .flatMap((innerInner) => innerInner.value);
for of
const result3 = []; for (const outer of data) { for (const inner of outer.items) { for (const innerInner of inner.innerItems) { result3.push(innerInner.value); } } }
reduce
const result = data.reduce((acc, outer) => { return outer.items.reduce((accInner, inner) => { return inner.innerItems.reduce((accInnerInner, innerInner) => { accInnerInner.push(innerInner.value); return accInnerInner; }, accInner); }, acc); }, []);