How can I use map and filter together in JavaScript?

How can I use map and filter together in JavaScript?

You can chain map and filter to transform and filter arrays. For example, you can first filter out unwanted items and then map the remaining items to a new format.

Can you show me a code example?

Sure! Here's an example:

const numbers = [1, 2, 3, 4, 5, 6];
const result = numbers.filter(num => num % 2 === 0).map(num => num * 2);
console.log(result); // Output: [4, 8, 12]

What does this code do exactly?

This code filters the array to keep only even numbers and then doubles each of those numbers.

Are there any performance considerations when chaining these methods?

Yes, chaining can be less performant than using a single loop, especially for large arrays, as it creates intermediate arrays.