How do filter and reduce work in Java streams?

Can you explain how filter and reduce work in Java streams?

Sure! In Java streams, filter is used to select elements based on a condition, while reduce aggregates elements into a single result.

Can you give me an example of using filter?

Absolutely! For instance, if you have a list of integers, you can use filter to get only the even numbers: list.stream().filter(n -> n % 2 == 0).collect(Collectors.toList());

And how about reduce? What does it look like?

For reduce, you can sum up all the numbers in a list like this: list.stream().reduce(0, Integer::sum); This will give you the total sum.

Can I combine filter and reduce in one stream?

Yes, you can! You can chain them together like this: list.stream().filter(n -> n % 2 == 0).reduce(0, Integer::sum); This will sum all even numbers.