Polymorphism vs Strategy pattern

Question

What is the difference between the Strategy pattern and Polymorphism in Java?

I\'m confused that whatever is achieved via Strategy Pattern is

Answer 1

One definition for Polymorphism is the provision of a single interface to entities of different types.

With that in mind say you have a “bird” interface and all of your bird classes must implement “laysEggs()” method, well no biggie that works. And as you keep coding your “bird paradise program” you now add the “fly()” and realize that overloading and overriding for penguin and kiwi is unnecessary as in real life they can't fly, yet you must still implement that method. This can become tedious and pointless as you are faced with Ostrich and others that can't fly. And even worst off when adding the method “swim()” because even fewer birds can swim. As you may already know, the strategy pattern solves this problem.

In lame-man’s terms you can think of Polymorphism as a conglomerate of practices, while the Strategy Pattern is the best practice for a specific case. Example: the Strategy Pattern is to be used when an algorithm's behavior needs to be selected at Runtime (via interchangeable algorithms). And although it is sort of true that whatever is achieved via Strategy Pattern is basically possible by polymorphism, without knowledge of the Strategy Pattern this would leave you with the “reinvent the wheel” problem to solve this specific problem. In conclusion, they are very different even if one is based on the other. I'll leave you to see “Ender Muab'Dib” code as it is well explained if you still want a code example from me just ask, cheers and hope I helped.