Java Lambda Expressions Coding Questions and Answers

Welcome to the Java Lambda Expressions Coding Quiz. In this quiz, we present 10 coding MCQ questions to test your coding knowledge of the Java Lambda Expressions. Each question has a correct and brief explanation.

1. What is the output of the following Java code snippet?

Runnable r = () -> System.out.println("Hello Lambda!");
r.run();
a) Hello Lambda!
b) Compilation error
c) No output
d) Runtime error

2. What does this Java code snippet output?

Function<Integer, Integer> func = x -> x * x;
System.out.println(func.apply(5));
a) 10
b) 25
c) 30
d) 5

3. Identify the output of the following code:

Predicate<String> isLongerThan5 = s -> s.length() > 5;
System.out.println(isLongerThan5.test("Lambda"));
a) true
b) false
c) Compilation error
d) Runtime error

4. What will be printed by this Java code?

Consumer<String> printer = s -> System.out.println(s.toUpperCase());
printer.accept("lambda");
a) lambda
b) LAMBDA
c) Lambda
d) Compilation error

5. What does this code snippet output?

Supplier<String> stringSupplier = () -> "Java";
System.out.println(stringSupplier.get());
a) Java
b) ""
c) null
d) Compilation error

6. What is the result of executing this code?

BiFunction<Integer, Integer, Integer> adder = (a, b) -> a + b;
System.out.println(adder.apply(10, 5));
a) 15
b) 10
c) 5
d) Compilation error

7. What will the following Java code snippet output?

IntUnaryOperator doubleNumber = x -> x * 2;
System.out.println(doubleNumber.applyAsInt(4));
a) 2
b) 4
c) 8
d) 16

8. What does the following code snippet print?

BinaryOperator<Integer> multiplier = (a, b) -> a * b;
System.out.println(multiplier.apply(3, 7));
a) 10
b) 21
c) 24
d) 30

9. Determine the output of this Java code:

List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
names.forEach(name -> System.out.println(name.toUpperCase()));
a) Alice Bob Charlie
b) alice bob charlie
c) ALICE BOB CHARLIE
d) Alice\nBob\nCharlie

10. What is the result of the following code snippet?

UnaryOperator<String> exclaim = s -> s + "!";
String result = exclaim.apply("Hello");
System.out.println(result);
a) Hello
b) Hello!
c) Hello!!
d) Compilation error

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