Benefit of Polymorphism [closed]

Answer 1

It is useful when you handle lists... A short example:

List<CoolingMachines> coolingMachines = ... // a list of CoolingMachines 
for (CoolingMachine current : coolingMachines) {
    current.start();
}

Or when you want to allow a method to work with any subclass of CoolingMachines

Answer 2

Because later if you want to use AirConditioner instead of Refrigerator for cooling, then only code you need to change is CoolingMachines cm = new AirConditioner();

Answer 3

A simple use case of polymorphism is that you can have an array of coolingMachines where element 0 is a refrigator and element 1 is an AirConditioner etc...

You do not need to preform any checks or make sure which object you are dealing with in order to call trip or start etc.

This can be a great benefit when taking input from a user and having to iterate over all the objects and call similar functions