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Saturday, November 11, 2017

C++ programming language part: 48 Classes and Objects


Classes and Objects

The important elements of a object-oriented language are classes. You can define many objects and functions of the same classes. All the objects share the same copy of the member function but maintains a separate copy of the member data.The stracture of a class as follows: 

Class specifier
The specifier for a class starts with the keyword class and Name , the body of the class delimites by braces and is terminated by a semicolon,
class nova
{
     // member data
    // member function
};


Defining Object
An object suppose K is an instant of a class called nova as follows
nova k;                // k is called object


Access Specifiers
The body of the class contains two keyword: private and public
Private data or function can only be accesses from within the class. Public data or functions, on the other hand, are accessible outside the class. It is not possible to access the member data directly from function main() as they are private to the nova class. These data can be accessed only from the member function of that class.

  
 Program 38_1
            //class & object.demo
            #include
            #include
            class nova           //class defined
            {
            private:
               int age;         // member data
               char name[10];
public:
            void data_in()   // member function
            {
                        cout<<" Type your age "<
                        cin>>age;
                        cout<<"Type your name "<
                        cin>>name;
            }
               void data_out()   // member function
            {
                        cout<<" The age is "<
                        cout<<" The name is "<
            }
            };

            void main()
            {
             nova k;               // k is called object
             k.data_in();       //would be k->data_in() if pointer
             k.data_out();
           }

Program 38_2
            class nova           //class defined
            { private:
               int a,b,c;         // member data
             public:
              void data_in()   // member function
            { cout<<" Type two nunbers "<
               cin>>a>>b;  }
            void add()       // member function
            {  c=a+b;  }
            void data_out()   // member function
            {  cout<<" The sum is "<
            };
            void main()
            {
             nova k;               // k is called object
             k.data_in();       //would be k->data_in() if pointer
             k.add();
             k.data_out();  

             }





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