How do different JavaScript array methods compare?

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

The main differences are:

• map creates a new array by applying a function to each element.
• forEach executes a function on each element but doesn't return a new array.
• filter creates a new array with elements that pass a test.

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

Sure!

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

When should I use one method over the others?

Use map when you want to transform data, forEach for side effects, and filter to select specific elements.

Are there performance differences between these methods?

Yes, performance can vary based on the size of the array and the complexity of the callback function. Generally, forEach is the fastest for simple operations, while map and filter may be slower due to creating new arrays.