Defining and Instantiating Classes

Let’s start by creating a Calculator class and adding some methods to it, step by step.

In Ruby, we define a class like this:

That’s all. It’s not a very useful class because it’s completely empty, but it’s a class.

Remember: A class is defined using the class keyword, a name, and the end keyword.

Use capital letters to define classes

Notice also that the class has the name Calculator, which starts with an uppercase letter. In Ruby, this is required, and we’d get an error if we tried to define a class called ...