Design patterns like State and Chain of Responsibility show us how using inheritance and polymorphism can make programming easier and more flexible.

State Pattern

• What it is: This pattern lets an object change how it behaves when its internal state changes.
• Inheritance: Different states are represented by subclasses, which inherit methods from a shared base.
• Example: Think of a Document class that has states like Draft, Review, and Published. Each state can use the publish() method in its own way.

Chain of Responsibility

• What it is: This pattern passes a request through a series of handlers.
• Polymorphism: Each handler can either deal with the request or pass it on to the next one.
• Example: In a support ticket system, there are classes like TechnicalSupport, BillingSupport, and GeneralSupport. They all inherit from a common interface and handle requests based on what they specialize in.

Both of these patterns show how inheritance and polymorphism play a big role in making object-oriented programming better.