Run results for: nested spread vs forEach push

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

Test name	Executions per second
spread	372.1 Ops/sec
forEach push	266.9 Ops/sec

Script Preparation code:

const arrNested = Array.from(Array(1000).keys());
const arr = new Array(1000).fill(null).map((item) => ({
	nested: [...arrNested],
}));

Tests:

spread
const resultSpread = []; arr.forEach((item) => { resultSpread.push(...item.nested); });
forEach push
const resultNestedLoop = []; arr.forEach((item) => { item.nested.forEach((nestedItem) => resultNestedLoop.push(nestedItem)); });