How can I use filter and reduce in JavaScript effectively?

How can I use filter and reduce in JavaScript effectively?

You can use filter to create a new array with elements that pass a test, and reduce to accumulate values. Would you like an example?

Yes, please provide an example using an array of numbers.

Sure! Let's say you have an array: [1, 2, 3, 4, 5]. You can use filter to get even numbers: const evens = arr.filter(num => num % 2 === 0); Then, use reduce to sum them: const sum = evens.reduce((acc, num) => acc + num, 0); This will give you the sum of even numbers.

That's great! Can you explain how the initial value in reduce works?

Absolutely! The initial value in reduce sets the starting point for the accumulator. If you provide it, the first element of the array is not used as the initial accumulator. If you don't provide it, the first element is used as the initial value, and the reduction starts from the second element.