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

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

A - Optional curly braces - No need to use curly braces in expression body if the body contains a single statement.

B - Optional return keyword - The compiler automatically returns the value if the body has a single expression to return the value.

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 function that accepts a double-valued argument and produces a result?

A - DoubleFunction<R>

B - DoublePredicate

C - DoubleSupplier

D - DoubleToIntFunction

Answer : A

Explanation

DoubleFunction<R> functional interface represents a function that accepts a double-valued argument and produces a 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 on a single long-valued operand that produces a long-valued result?

A - LongToDoubleFunction

B - LongToIntFunction

C - LongUnaryOperator

D - ObjDoubleConsumer<T>

Answer : C

Explanation

LongUnaryOperator functional interface represents an operation on a single long-valued operand that produces a long-valued result.

Q 5 - Which of the following functional interface represents a predicate (Boolean-valued function) of one argument?

A - ObjIntConsumer<T>

B - ObjLongConsumer<T>

C - Predicate<T>

D - Supplier<T>

Answer : C

Explanation

Predicate<T> functional interface represents a predicate (Boolean-valued function) of one argument.

Q 6 - Which of the following is correct about streams in java8?

A - Intermediate operation's function is to take input, process them, and return output to the target.

B - collect() method is a terminal operation which is normally present at the end of the pipelining operation to mark the end of the stream.

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 API represents a simplified date-time API with no complexity of timezone handling in java8?

C - Both of the above.

D - None of the above.

Answer : A

Explanation

Local − Simplified date-time API with no complexity of timezone handling.

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

Answer : B

Explanation

Optional object is used to represent null with absent value.

Q 10 - Optional.ofNullable method allows passed parameter to be null.

Answer : A

Explanation

Optional.ofNullable method allows passed parameter to be null.

java8_questions_answers.htm

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