What is so great about classes?
Classes are there to help you organize your code and to reason about your programs. You could roughly equivalently say that classes are there to help you avoid making mistakes and to help you find bugs after you do make a mistake. In this way, classes significantly helps maintenance. A class is the representation of an idea, a concept, in the code. An object of a class represents a particular example of the idea in the code. Without classes, a reader of the code would have to guess about the relationships among data items and functions – classes make such relationships explicit and “understood” by compilers. With classes, more of the high-level structure of your program is reflected in the code, not just in the comments. A well-designed class presents a clean and simple interface to its users, hiding its representation and saving its users from having to know about that representation.
