Run results for: hb-2365-test

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:66.0) Gecko/20100101 Firefox/66.0

Browser: Firefox 66

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Not optimized	2.2 Ops/sec
Optimized	305.7 Ops/sec

Script Preparation code:

const arr = Array(500).fill(null);
var parents = arr.map(() => {
    return {
        children: arr.map((value, index) => ({value, selected: index % 2})),
    };
});

Tests:

Not optimized
let out = []; parents.forEach(parent => { const selected = parent.children.filter(child => child.selected).map(child => child.value); out = [...out, ...selected]; });
Optimized
const out = []; parents.forEach(parent => { parent.children.forEach(child => child.selected && out.push(child.value)); });

Run results for: hb-2365-test

Not optimized

Optimized