What are the differences between array methods in JavaScript?

What are the main differences between map, filter, and forEach in JavaScript?

The main differences are:

1. map creates a new array by applying a function to each element.
2. filter creates a new array with elements that pass a test.
3. forEach executes a function on each element but does not return a new array.

Can you give me an example of how to use each of these methods?

Sure!

• map: const doubled = arr.map(num => num * 2);
• filter: const evens = arr.filter(num => num % 2 === 0);
• forEach: arr.forEach(num => console.log(num));

When should I use filter instead of map?

Use filter when you want to create a new array with only the elements that meet a certain condition. Use map when you want to transform each element into a new value.

Are there any performance differences between these methods?

Yes, performance can vary. Generally, forEach is faster for simple iterations, while map and filter may be slower due to creating new arrays. However, the difference is often negligible for small arrays.