How does the reduce method differ from the traditional use of loops for processing collections?

The reduce method in Java (more often through the Stream API) allows you to reduce a collection to a single value by applying an accumulator function. Unlike traditional loops, reduce:

• Is more declarative: it describes what needs to be done, not how.
• Enables writing more concise and readable code.
• Works well with functional style and parallel processing.

Example of summing list elements using reduce:

List<Integer> numbers = Arrays.asList(1, 2, 3, 4);
int sum = numbers.stream()
                 .reduce(0, (acc, n) -> acc + n);
System.out.println(sum); // 10

In a traditional loop, it would look like this:

int sum = 0;
for (int n : numbers) {
    sum += n;
}
System.out.println(sum); // 10

Thus, reduce helps express the logic of collection folding more functionally and concisely.