Rules for Naming Interfaces in OOP in PHP

As already mentioned above, there cannot be an interface and a class with the same name. This creates some problems with coming up with names. For example, we want to create a class User that implements the User interface. As we can see, we have a name conflict. To resolve it, we need to either name the class differently, or the interface.

It is generally accepted in such cases to start the interface name with a lowercase letter i to show that it is an interface, not a class. That is, in our case, we will make the interface iUser, and it will be implemented by the class User. We will sometimes use this approach in the following lessons.