Apex Design Patterns

An interface

An interface is another way to achieve polymorphism and abstraction in Apex. Interfaces are like a contract. We can only add a declaration to a class but not the actual implementation. You might be thinking about why do we need to create a class, which does not have anything in it? Well, I will ask you to think about this again after taking a look at the following example.

We will continue with the Mario example. Like any game, this game also needs to have levels. Every level will be different from the previous; and therefore, the code cannot be reused. Inheritance was very powerful because of the dynamic dispatch polymorphic behavior; however, inheritance can not be used in this scenario.

We will be using an interface to define levels ...