When should I use map vs forEach in JavaScript?

Can you explain when to use map and when to use forEach in JavaScript?

Sure! Use map when you want to transform an array and create a new one, and use forEach for executing a function on each element without creating a new array.

What’s the main difference in their return values?

The main difference is that map returns a new array with the results of calling a provided function on every element, while forEach returns undefined.

Can you give me an example of both?

Absolutely! For map, you might do: const doubled = arr.map(num => num * 2);. For forEach, it would be: arr.forEach(num => console.log(num));.

Are there any performance considerations between the two?

Yes, map can be slightly slower due to creating a new array, while forEach is generally faster since it doesn't return anything.