Complete Java SE 8 Developer Bootcamp - Interface: Part 3

The video tutorial explains the importance of interfaces in Java, focusing on their role in enabling polymorphism. It discusses how interfaces allow for the creation of variable reference types and the implementation of multiple interfaces, providing a form of multiple inheritance. The tutorial also covers naming conventions for interfaces and the use of default methods introduced in Java 8. Additionally, it introduces the concept of a payable interface and how it can improve the architecture of an employee class by enforcing method implementation in subclasses.

What is the primary benefit of using interfaces in programming?

• They simplify the syntax of programming languages.

• They enable polymorphism by allowing different objects to be treated as the same type.

• They allow for the creation of multiple instances of a class.

• They provide a way to store data persistently.

Why can't you call the 'area' method on a drawable reference?

• Because 'area' is only available in the shape class.

• Because 'area' is a private method.

• Because 'area' requires additional parameters.

• Because 'area' is not a method in the drawable interface.

What is a polymorphic method?

• A method that can be called on any object.

• A method that can operate on objects of different types.

• A method that changes its behavior based on input parameters.

• A method that is defined in multiple classes.

What is a key advantage of implementing multiple interfaces?

• It allows a class to inherit multiple methods from different classes.

• It enables a class to have multiple constructors.

• It provides a form of multiple inheritance.

• It allows a class to change its type at runtime.

What must a class do if it implements multiple interfaces with the same default method signature?

• It must remove one of the interfaces.

• It must implement a new interface.

• It must override the method to resolve ambiguity.

• It must choose one of the default methods to use.

What is a common naming convention for interfaces?

• Using verbs to describe actions.

• Using nouns to describe objects.

• Using adjectives or ending with 'able'.

• Using numbers to indicate versions.

How does the payable interface improve system architecture?

• By providing default implementations for methods.

• By enforcing method implementation in subclasses.

• By allowing multiple classes to be instantiated.

• By reducing the number of classes needed.