Java 8 Online 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.

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

Q 3 - Which of the following functional interface represents a predicate (Boolean-valued function) of one int-valued argument?

A - IntConsumer

B - IntFunction<R>

C - IntPredicate

D - IntSupplier

Q 4 - Which of the following functional interface represents an operation upon two long-valued operands and produces a long-valued result?

A - IntToDoubleFunction

B - IntToLongFunction

C - IntUnaryOperator

D - LongBinaryOperator

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>

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

A - Stream represents a sequence of objects from a source, which supports aggregate operations.

B - Most of the stream operations return stream itself so that their result can be pipelined.

C - Both of the above.

D - None of the above.

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

A - This class has various utility methods to facilitate code to handle values as 'available' or 'not available' instead of checking null values.

B - It is introduced in Java 8 and is similar to what Optional is in Guava.

C - Both of the above.

D - None of the above.

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

Q 9 - A stream provides a set of elements of specific type in a sequential manner.

A - true

B - false

Q 10 - The new date-time API in java 8 is immutable and does not have setter methods.

A - true

B - false