22.1. Functional Programming in Java

Try these first

1. 1.

   What is a lambda expression?

   Hint

   Think about the syntax and purpose of lambda expressions.

2. 2.

   Define a functional interface.

   Hint

   Recall the main characteristic of a functional interface.

3. 3.

   What is a lambda expression primarily used for in Java?

   • Implementing multiple interface methods
   • Creating an anonymous function
   • Declaring a class

   Hint

   Consider what happens when you use a lambda expression.

4. 4.

   True or False: A functional interface can contain multiple abstract methods.

   • True
   • False

   Hint

   Recall the definition of functional interfaces.

5. 5.

   Create a functional interface with a method that calculates the area of a rectangle and implement it using a lambda expression.

   Hint

   Remember to define both the interface and the lambda implementation.

6. 6.

   Explain the role of 'final' and 'effectively final' in lambda expressions with an example.

   Hint

   Consider how variable scope works in lambda expressions.