How do map and filter work in JavaScript?

Can you explain how the map and filter methods work in JavaScript?

Sure! The map method creates a new array by applying a function to each element of the original array, while filter creates a new array with elements that pass a test defined by a function.

Can you give me an example of using both methods?

Of course! Here's an example:

const numbers = [1, 2, 3, 4, 5];
const doubled = numbers.map(num => num * 2); // [2, 4, 6, 8, 10]
const evenNumbers = numbers.filter(num => num % 2 === 0); // [2, 4]

What if I want to use them together?

You can chain them! For example:

const result = numbers.filter(num => num % 2 === 0).map(num => num * 2); // [4, 8]

Are there any performance considerations I should be aware of?

Yes, chaining methods can lead to performance issues with large arrays, as each method creates a new array. Consider using a single loop if performance is critical.