I think the map method runs synchronously

app.js

let myBigArray = []

for(let i=0; i<2000000; i++) {
  myBigArray.push(i);
}

console.log('Done filling the array.');

let myNewBigArray = myBigArray.map( (e) => {
  return e+2;
});

// if map ran *asynchronously* then when we try to console.log the last element
// of myNewBigArray, we would get an error.
console.log(`Last element of myNewBigArray: ${myNewBigArray[myNewBigArray.length-1]}`);

console.log('Done with map');