Java 8 Online Quiz


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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

Answer : A

Explanation

System.out::println method is a static method reference to println method of out object of System class.

Q 2 - Which of the following functional interface represents an operation that accepts a single double-valued argument and returns no result?

A - BooleanSupplier

B - Consumer<T>

C - DoubleBinaryOperator

D - DoubleConsumer

Answer : D

Explanation

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

Q 3 - Which of the following functional interface represents an operation on a single double-valued operand that produces a double-valued result?

A - DoubleToLongFunction

B - DoubleUnaryOperator

C - Function<T,R>

D - IntBinaryOperator

Answer : B

Explanation

DoubleUnaryOperator functional interface represents an operation on a single double-valued operand that produces a double-valued result.

Q 4 - Which of the following functional interface represents a supplier of long-valued results?

A - LongConsumer

B - LongFunction<R>

C - LongPredicate

D - LongSupplier

Answer : D

Explanation

LongSupplier functional interface represents a supplier of long-valued results.

Q 5 - Which of the following functional interface represents an operation that accepts an object-valued and a long-valued argument, and returns no result?

A - ObjIntConsumer<T>

B - ObjLongConsumer<T>

C - Predicate<T>

D - Supplier<T>

Answer : B

Explanation

ObjLongConsumer<T> functional interface represents an operation that accepts an object-valued and a long-valued argument, and returns no result.

Answer : C

Explanation

Both of the above options are correct.

Q 7 - Which of the following class implements a decoder for decoding byte data using the Base64 encoding scheme in Java8?

A - Base64.Decoder

B - Base64.Encoder

C - Base64Decoder

D - Base64Encoder

Answer : A

Explanation

static class Base64.Decoder - This class implements a decoder for decoding byte data using the Base64 encoding scheme as specified in RFC 4648 and RFC 2045.

Q 8 - Lambda expressions are used primarily to define inline implementation of a functional interface.

A - true

B - false

Answer : A

Explanation

Lambda expressions are used primarily to define inline implementation of a functional interface.

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

A - false

B - true

Answer : B

Explanation

Functional interfaces have a single functionality to exhibit.

Q 10 - java.util.Date is not thread safe, thus developers have to deal with concurrency issue while using date.

A - true

B - false

Answer : A

Explanation

java.util.Date is not thread safe, thus developers have to deal with concurrency issue while using date.

java8_questions_answers.htm
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