Classes like Animal and Fruit make it easy to understand the concepts of classes and instances, but you probably won’t see many zebras or lemons in real-world programs.

However, classes and objects are often used to model real-world objects. The code in the editor is a more realistic demonstration of the kind of classes and objects you might find in commercial software. Here we have a basic ShoppingCart class for creating shopping cart objects for website customers; though basic, it’s similar to what you’d see in a real program.