Java Operators

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Object Oriented Programming

Java Built-in Classes

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Advanced Java

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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 - Optional type declaration - No need to declare the type of a parameter. The compiler can inference the same from the value of the parameter.

B - Optional parenthesis around parameter - No need to declare a single parameter in parenthesis. For multiple parameters, parentheses are required.

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 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 upon two int-valued operands and produces an int-valued result?

A - DoubleToLongFunction

B - DoubleUnaryOperator

C - Function<T,R>

D - IntBinaryOperator

Answer : D

Explanation

FunctionIntBinaryOperator functional interface represents an operation upon two int-valued operands and produces an int-valued result.

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

A - LongToDoubleFunction

B - LongToIntFunction

C - LongUnaryOperator

D - ObjDoubleConsumer<T>

Answer : A

Explanation

LongToDoubleFunction functional interface represents a function that accepts a long-valued argument and produces a double-valued result.

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

A - ToLongBiFunction<T,U>

B - ToLongFunction<T>

C - UnaryOperator<T>

D - ToIntFunction<T>

Answer : A

Explanation

ToLongBiFunction<T,U> functional interface represents a function that accepts two arguments and produces a long-valued result.

Q 6 - How will you call a static method of an interface in a class?

A - Using super keyword along with interface name.

B - Using name of the interface.

C - Both of the above.

D - None of the above.

Answer : B

Explanation

Using name of the interface.

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?

Answer : A

Explanation

getUrlDecoder() method of Base64 class returns a Base64.Decoder that decodes using the URL and Filename safe type base64 encoding scheme.

Q 9 - Stream supports aggregate operations like filter, map, limit, reduce, find and match.

A - false

B - true

Answer : B

Explanation

Stream supports aggregate operations like filter, map, limit, reduce, find, match, and so on.

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.

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