Programs are composed of a set of modules called classes. Each class is a template specifying a set of behaviors on the data of the class. |
Each class has instance variables to hold the data and methods (called functions or procedures in other languages) to define the behaviors. Each object in a program is created as an instance of a class. Each class instance has its own copy of the instance variables. |
Classes can be used for data encapsulation, hiding the details of the data representation from the user of the class (by marking variables as private). |
Instance |
Variables |
Methods |