How does filter compare to map and forEach?

Can you explain the differences between filter, map, and forEach in JavaScript?

Sure! In JavaScript, filter, map, and forEach are array methods that serve different purposes. Filter creates a new array with elements that pass a test, map creates a new array with the results of calling a function on every element, and forEach executes a provided function once for each array element.

Can you give me an example of how each method works?

Of course! For filter, you might use it to get all even numbers from an array. For map, you could use it to double each number in an array. For forEach, you might log each number to the console. Would you like to see code examples?

Yes, please provide the code examples!

Here’s an example:

1. Filter: const evens = arr.filter(num => num % 2 === 0);
2. Map: const doubled = arr.map(num => num * 2);
3. ForEach: arr.forEach(num => console.log(num));

Let me know if you need further clarification!

What are the performance differences between these methods?

Performance can vary based on the size of the array and the complexity of the callback function. Generally, filter and map create new arrays, which can be more memory-intensive, while forEach does not return anything and is often faster for simple operations.