SE450: Inheritance [18/76]

• More general class = superclass
• More specialized class = subclass
• Subclass supports all method interfaces of superclass (but implementations may differ)
• Subclass may have added methods, added state
• Subclass inherits from superclass
• Example: ForwardedMessage inherits from Message
• Example: Greeting does not inherit from Message (Can't store greetings in mailbox)