easy2.md

🚫Issue in the Hierarchy (Why it Violates LSP?)

Liskov Substitution Principle (LSP) states that a subclass should be substitutable for its base class without breaking functionality.

• Here, Penguin inherits the fly() method from Bird, but penguins cannot fly in reality.
• If we use a Penguin object in place of a Bird and call fly(), it will produce incorrect behavior.
• This violates LSP because not all Birds can fly, but Bird assumes that all of its subclasses will support fly().

✅How the Refactored Code Follows LSP

1. Created an abstract Bird class
   • Bird no longer assumes all birds can fly. Instead, it has a generic move() method.
   • Penguin and Parrot both extend Bird, but each defines movement appropriately.
2. Introduced a CanFly Interface
   • Only birds that can actually fly (like Parrot) implement the CanFly interface.
   • Penguin does not implement CanFly, so it never has an incorrect fly() method .

🔹Summary of Fixes

Problem	Before Refactoring	After Refactoring
LSP Violation	Penguin extends Bird but inherits fly(), which it shouldn't.	Bird class no longer assumes all birds fly .CanFly interface is introduced.
Incorrect Behavior	Calling penguin.fly() is logically incorrect.	Penguinsdo not have a fly()method , preventing misuse.
Better Code Structure	One big class with misleading behavior.	A properhierarchy using abstraction & interfaces .

-> Final Benefits

✅ Ensures correct behavior – Penguin never has an invalid fly() method. ✅ Follows LSP – Substituting Penguin or Parrot for Bird does not break functionality. ✅ Easier to extend – We can add more bird types without modifying existing code.

This approach ensures maintainability, correctness, and compliance with Liskov’s Substitution Principle !