Classes

Chapter‒2

Classes and Objects

Classes

• Each class is a collection of data and functions that manipulate the data.

• Placing the data and functions together into a single entity is the central idea in object oriented programming.

• The nouns in the system specification help the C++ programmer to determine the set of classes. The objects for these classes are created. These objects work together to implement the system.

• Classes in C++ is the natural evolution of C notion of struct.

For example:

class rectangle

{

       private:

       int len,br;

       public:

       void get_data();

       void area();

       void print_data();

};

• Rules for declaring class name 

1. The class name must begin with the letters, it may be followed by letters, digits or underscore.

2. The name of the class must not be same as keyword or reserved word.

3. The class name must not contain any special character such as ~,!,@,#,$, %,^,&,*,(,), {,}, [,],+,‒,,/,\

Difference between Structure and Class

Structure

1.By default the members of structure are public.

2.The structure can not be inherited.

3.The structures do not require constructors.

4. A structure contains only data members.

Class

1. By default the members of class are private.

2. The class can be inherited.

3. The classes require constructors for initializing the objects.

4. A class contains the data as well as the function members.