The object-oriented model is very powerful. An object-oriented application consists of objects. An object exists in memory during the execution of the application. In C++, an object is defined by its class. A class can be considered a blueprint for one or more objects with the same features. A class is defined by methods and fields. A method is a function enclosed in a class. A field is a variable common to the whole class. The methods and fields of a class are together referred to as its members.

The foundation of the object-oriented theory rests on three cornerstones: part of class can be encapsulated, classes can inherit each other, and objects can be bound dynamically.

There are five relations in the object-oriented model. A class is defined in the source code, and one or more object of that class is created during the execution, the objects are instances of the class. A method of one class calls a method of the same class or another class. A class can inherit...