Can someone explain the benefits of polymorphism?

Question

So I understand pretty much how it works, but I just can\'t grasp what makes it useful. You still have to define all the separate functions, you still have to create an instanc

Answer 1

Say you want someone to show up for work. You don't know whether they need to take a car, take a bus, walk, or what. You just want them to show up for work. With polymorphism, you just tell them to show up for work and they do. Without polymorphism, you have to figure out how they need to get to work and direct them to that process.

Now say some people start taking a Segway to work. Without polymorphism, every piece of code that tells someone to come to work has to learn this new way to get to work and how to figure out who gets to work that way and how to tell them to do it. With polymorphism, you put that code in one place, in the implementation of the Segway-rider, and all the code that tells people to go to work tells Segway-riders to take their Segways, even though it has no idea that this is what it's doing.

There are many real-world programming analogies. Say you need to tell someone that there's a problem they need to investigate. Their preferred contact mechanism might be email, or it might be an instant message. Maybe it's an SMS message. With a polymorphic notification method, you can add a new notification mechanism without having to change every bit of code that might ever need to use it.