Streams

What is a functional interface in Java?

• • An interface that has only one abstract method

  
  

• An interface that has only one default method

• An interface that has only one static method

• An interface that has no methods

What is the syntax of a lambda expression in Java?

• (parameters) -> {body}

• [parameters] -> {body}

• {parameters} -> [body]

• [parameters] -> [body]

What is the benefit of using lambda expressions in Java?

• They make the code more complex and verbose

• • They make the code more secure and robust

  
  

• • They make the code more concise and readable

  
  

• • They make the code more dynamic and flexible

  
  

What is a stream in Java?

• A sequence of bytes that can be read or written

• A sequence of characters that can be displayed or printed

• A sequence of numbers that can be sorted or searched

• A sequence of elements that can be processed with functional operations

What are the two types of stream operations in Java?

• 
  

• Filter and map

• Source and sink

• Intermediate and terminal

• Reduce and collect

Which of the following methods can be used to create an infinite stream in Java?

• Stream.generate()

• Stream.iterate()

• Stream.range()

• Both A and B

Which of the following methods can be used to perform a reduction operation on a stream in Java?

• stream.reduce()

• stream.collect()

• stream.sum()

• Both A and B

Which of the following methods can be used to create a stream from an array in Java?

• Arrays.stream(array)

• Stream.of(array)

• Stream.from(array)

• Both A and B

Which of the following functional interfaces represents a predicate (a boolean-valued function) in Java?

• Predicate<T,V>

• Predicate<T>

• Predicated<T>

• Don't know

Which of the following functional interfaces represents a function that accepts two arguments and produces a result in Java?

• BiFunction<T, U, R>

• BinaryOperator<T>

• BiConsumer<T, U>

• BiPredicate<T, U>