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Java 8 Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Java 8. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - Which of the following is correct about Java8?

A - Lambda expression - Adds functional processing capability to Java.

B - Method references - Referencing functions by their names instead of invoking them directly. Using functions as parameter.

C - Default method - Interface to have default method implementation.

D - All of the above.

Answer : D

Explanation

All of the above options are correct.

Q 2 - Which of the following functional interface represents an operation upon two double-valued operands and producing a double-valued result?

A - BooleanSupplier

B - Consumer<T>

C - DoubleBinaryOperator

D - DoubleConsumer

Answer : C

Explanation

DoubleBinaryOperator functional interface represents an operation upon two double-valued operands and producing a double-valued result.

Q 3 - Which of the following functional interface represents an operation that accepts a single int-valued argument and returns no result?

A - IntConsumer

B - IntFunction<R>

C - IntPredicate

D - IntSupplier

Answer : A

Explanation

IntConsumer functional interface represents an operation that accepts a single int-valued argument and returns no result.

Q 4 - Which of the following functional interface represents an operation that accepts a single long-valued argument and returns no result?

A - LongConsumer

B - LongFunction<R>

C - LongPredicate

D - LongSupplier

Answer : A

Explanation

LongConsumer functional interface represents an operation that accepts a single long-valued argument and returns no result.

Q 5 - Which of the following functional interface represents a function that produces a double-valued result?

A - ToDoubleBiFunction<T,U>

B - ToDoubleFunction<T>

C - ToIntBiFunction<T,U>

D - ToIntFunction<T>

Answer : B

Explanation

ToDoubleFunction<T> functional interface represents a function that produces a double-valued result.

Q 6 - Which of the following is correct about default methods?

A - With java 8, an interface can have default implementation of a function in interfaces.

B - An interface can also have static helper methods from Java 8 onwards.

C - Both of the above.

D - None of the above.

Answer : C

Explanation

Both of the above options are correct.

Q 7 - Which of the following is correct about Nashorn in java8?

A - With Java 8, Nashorn, a much improved javascript engine is introduced, to replace the existing Rhino.

B - Nashorn provides 2 to 10 times better performance, as it directly compiles the code in memory and passes the bytecode to JVM.

C - Nashorn uses invokedynamics feature, introduced in Java 7 to improve performance

D - All of the above.

Answer : D

Explanation

All of the above options are correct.

Q 8 - Which of the following method of Base64 class returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme?

A - getDecoder()

B - getEncoder()

C - getMimeDecoder()

D - getMimeEncoder

Answer : A

Explanation

getDecoder() method of Base64 class returns a Base64.Decoder that decodes using the Basic type base64 encoding scheme.

Q 9 - Functional interfaces have a single functionality to exhibit.

Answer : B

Explanation

Functional interfaces have a single functionality to exhibit.

Q 10 - Optional.of method throws NullPointerException if passed parameter is null.

Answer : A

Explanation

Optional.of method throws NullPointerException if passed parameter is null.

java8_questions_answers.htm

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