Run results for: Flat vs forEach + push

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36

Browser: Chrome 105

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Flat	3830.0 Ops/sec
forEach + push	38575.7 Ops/sec

Script Preparation code:

var myArray = [];
var x = 2000;
while (myArray.length < x) {
  myArray.push([{a: 'b'}])
}

Tests:

Flat
myArray .map((each) => { return each.map((deet) => { return { subject: deet.a }; }); }) .flat();
forEach + push
let newArr = [] myArray.forEach((each) => { return each.forEach((deet) => { newArr.push({ subject: deet.a }) }) })