Inheritance and Polymorphism Examples in Java: AP Computer Science A Preparation

📚 Quick Study Guide

• 🌱 Inheritance: Allows a class (subclass) to inherit properties and methods from another class (superclass). Promotes code reuse and establishes an IS-A relationship.
• 🔑 Keyword 'extends': Used to implement inheritance. Example: class Dog extends Animal { ... }
• 🏗️ Superclass: The class being inherited from (also known as the parent class or base class).
• 🐕 Subclass: The class that inherits from another class (also known as the child class or derived class).
• 🔨 Method Overriding: When a subclass provides a specific implementation for a method that is already defined in its superclass.
• ✍️ Polymorphism: The ability of an object to take on many forms. Achieved through inheritance and interfaces.
• 🎭 Dynamic Binding (Late Binding): Resolving method calls at runtime, allowing for flexibility in object behavior.
• 📦 'super' keyword: Used to call the superclass's constructor or methods from within the subclass.

🧪 Practice Quiz

1. Which keyword is used to implement inheritance in Java?
   1. A. implements
   2. B. extends
   3. C. inherits
   4. D. uses
2. What is method overriding?
   1. A. Creating a new method in a class.
   2. B. Providing a specific implementation for a method in a subclass that is already defined in its superclass.
   3. C. Calling a method from another class.
   4. D. Deleting a method from a class.
3. Which concept allows an object to take on many forms?
   1. A. Inheritance
   2. B. Encapsulation
   3. C. Polymorphism
   4. D. Abstraction
4. What is the purpose of the 'super' keyword?
   1. A. To define a superclass.
   2. B. To call the superclass's constructor or methods.
   3. C. To create a new object.
   4. D. To delete an object.
5. What is the relationship between a subclass and a superclass?
   1. A. A subclass is a type of superclass.
   2. B. A superclass is a type of subclass.
   3. C. They are unrelated.
   4. D. They are the same.
6. What is dynamic binding?
   1. A. Binding variables at compile time.
   2. B. Binding methods at compile time.
   3. C. Resolving method calls at runtime.
   4. D. Preventing method calls.
7. Which of the following is an example of polymorphism?
   1. A. A class inheriting from another class.
   2. B. A method calling itself.
   3. C. An object being able to be treated as multiple types.
   4. D. A variable storing multiple values.