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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.

Q 1 - Which of the following is correct about Java 8 lambda expression?

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

B - Lambda expression eliminates the need of anonymous class and gives a very simple yet powerful functional programming capability to Java.

C - Both of the above.

D - None of the above.

Answer : C

Explanation

Both of the above options are correct.

Q 2 - Which of the following functional interface represents a predicate of one double-valued argument?

A - DoubleFunction<R>

B - DoublePredicate

C - DoubleSupplier

D - DoubleToIntFunction

Answer : B

Explanation

DoublePredicate functional interface represents a predicate (Boolean-valued function) of one double-valued argument.

Q 3 - Which of the following functional interface represents a function that accepts an int-valued argument and produces a result?

Answer : B

Explanation

IntFunction<R> functional interface represents a function that accepts an int-valued argument and produces a result.

Q 4 - Which of the following functional interface represents a function that accepts a long-valued argument and produces a result?

Answer : B

Explanation

LongFunction<R> functional interface represents a function that accepts a long-valued argument and produces a result.

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

A - ToLongBiFunction<T,U>

B - ToLongFunction<T>

C - UnaryOperator<T>

D - ToIntFunction<T>

Answer : B

Explanation

ToLongFunction<T> functional interface represents a function that produces a long-valued result.

Q 6 - What is the purpose of map method of stream in java 8?

A - Iterate each element of the stream.

B - Map each element to its corresponding result.

C - Eliminate elements based on a criteria

D - Reduce the size of the stream

Answer : B

Explanation

The 'map' method is used to map each element to its corresponding result.

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

A - Optional is a container object which is used to contain not-null objects.

B - Optional object is used to represent null with absent value.

C - Both of the above.

D - None of the above.

Answer : C

Explanation

Both of the above options are correct.

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