Java 8: Stream filter -> map -> collect pipeline

Streams process collections declaratively: keep, transform, then gather the results.

Code

List<Integer> nums = List.of(1, 2, 3, 4, 5, 6);
List<Integer> squaredEvens = nums.stream()
        .filter(n -> n % 2 == 0)
        .map(n -> n * n)
        .collect(Collectors.toList());
System.out.println(squaredEvens);

Output

[4, 16, 36]

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Published 2026-07-26