In what cases does the use of functional programming provide advantages?

Functional programming provides advantages in the following cases:

• When you need to write code that is easy to test and maintain, due to the absence of side effects.
• In systems with a high degree of parallelism, as immutability of data simplifies working with threads.
• When processing large volumes of data, for example, using higher-order functions (map, filter, reduce), which makes the code more expressive and concise.
• In projects where predictability of behavior and reliability are important, as pure functions always return the same result for the same inputs.

Example in Java using Stream API:

List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
List<Integer> evenSquares = numbers.stream()
    .filter(n -> n % 2 == 0)
    .map(n -> n * n)
    .collect(Collectors.toList());

System.out.println(evenSquares); // [4, 16]