Java 8 Online Quiz

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.

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

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

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

A - LongConsumer

B - LongFunction<R>

C - LongPredicate

D - LongSupplier

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

A - ToDoubleBiFunction<T,U>

B - ToDoubleFunction<T>

C - ToIntBiFunction<T,U>

D - ToIntFunction<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 Nashorn in java8?

A - With Java 8, Nashorn, a much improved javascript engine is introduced, to replace the existing Rhino.

B - Nashorn provides 2 to 10 times better performance, as it directly compiles the code in memory and passes the bytecode to JVM.

C - Nashorn uses invokedynamics feature, introduced in Java 7 to improve performance

D - All of the above.

Q 8 - Which of the following is the correct lambda expression which add two numbers and return their sum?

A - (int a, int b) -> { return a + b;};

B - (a, b) -> {return a + b;};

C - Both of the above.

D - None of the above.

Q 9 - Optional object is used to represent non null value with absent value.

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