Java Programming - MCQ Practice Questions

Consider a lambda expression: (String s) -> s.length(). What is the correct functional interface for this?

What will happen if you try to access a local variable from an enclosing scope that is not final or effectively final in a lambda expression?

Consider the code: List<String> names = Arrays.asList("Alice", "Bob"); names.forEach(name -> System.out.println(name)); What type of functional interface is used in forEach?

What is the output of: List<Integer> nums = Arrays.asList(1,2,3); nums.stream().filter(x -> x > 1).forEach(System.out::println);

Which lambda expression correctly implements a custom functional interface: public interface Math { int calculate(int a, int b); }

Consider: Comparator<Integer> comp = (a, b) -> b - a; List<Integer> list = Arrays.asList(3,1,2); Collections.sort(list, comp); What is the result?

Which of the following correctly uses a method reference as an alternative to a lambda expression?

Which stream operation uses a lambda expression to transform elements from one type to another?

Which of the following lambda expressions is INVALID in Java?

A stream processes a list of strings and applies a lambda to convert them to uppercase. Which intermediate operation should be used?

Consider the following code: List<String> fruits = Arrays.asList("apple", "banana", "cherry"); fruits.removeIf(s -> s.length() > 5); What will be the contents of 'fruits' list after execution?