Java Streams and Lambda Expressions

Evaluate your ability to use modern Java functional features.

1. Which of the following is a terminal stream operation?

filter map collect flatMap

2. Select all functional interfaces from the following:

Runnable Consumer List Predicate String

3. A lambda expression can be used wherever a functional interface is expected.

True False

4. What is the return type of the Stream.map() method? (Use generic notation)

5. Which lambda correctly represents a Consumer<Integer> that prints the integer?

(int x) -> { System.out.println(x); } x -> println(x) (x) -> System.out.println Integer x -> print(x)

6. Which are intermediate stream operations?

filter map collect forEach sorted

7. Java Streams modify the original collection they are created from.

True False

8. What method call converts a Stream<String> to a List<String> using Collectors?

9. What functional interface does Stream.filter() accept as an argument?

Predicate Consumer Function Supplier

10. Which can be target types for a lambda expression?

Runnable Callable<Integer> String List<String> Comparator<String>

11. A lambda can access and modify non-final local variables from the enclosing scope.

True False

12. Name the functional interface with a single abstract method 'apply' that takes one argument and returns a result.

13. What is the result of Stream.of(2, 4, 6, 8).count()?

4 [2, 4, 6, 8] 8 void

14. Select stateful intermediate stream operations:

filter sorted distinct map limit

15. Stream.forEach() returns a new Stream for further processing.

True False

Answered 0 of 0 — 0 correct

Company