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Saturday, November 11, 2017

C++ programming language part: 54 Scope Resolution with Overridden Members


Scope Resolution with Overridden Members

To access a base class member from a derived class, the scope resulation operator is used.  Attentively follow the following program.

Program 42_3
            //Scope resulation with overidden
            class furniture              //class defined
            {
              private:
              char color[10];
              int width,height;

              public:
              void data_in()
               {
              cout<<"Type color of bookshelf (red or blue?)\t";
               cin>>color;
               cout<<"Type width\t";
               cin>>width;
               cout<<"Type height\t";
               cin>>height;
               }

             void data_out()
             {
             cout<<" The color is "<
             cout<<" The width is "<
             cout<<" The height is "<
         }
        };
            class bookshelf:public furniture
        {
              private:
               int self_no;               // member data
              
               public:
               void data_in()
             {
               furniture::data_in();       // Scope Resolution Operator
               cout<<"Type number of selves\t";
               cin>>self_no;
             }
             
               void data_out() //member function
             {
               furniture::data_out();     // Scope Resolution Operator
               cout<<" Number of selves are "<
            }
            };
            class chair:public furniture
            {
               private:
               int leg_no;                
              
               public:
               void data_in()      //member function
             {
               furniture::data_in();        // Scope Resolution Operator
               cout<<"Type number of legs\t";
               cin>>leg_no;
             }
             
               void data_out() //member function
             {
               furniture::data_out();       // Scope Resolution Operator
               cout<<" Number of legs are "<
             }
             };

            void main()
            {
             bookshelf A;                // A,B is called object
             chair B;
             A.data_in();                //would be k->data_in() if pointer
             A.data_out();
             B.data_in();                 //would be k->data_in() if pointer
             B.data_out();

            }




Part- 86 assign the content of twostring



জ্ঞানকোষ প্রকাশনী
৩৮/২-ক, বাংলাবাজার (২য় তলা), ঢাকা।
       ফোনঃ ৭১১৮৪৪৩, ৮১১২৪৪১, ৮৬২৩২৫১.         
                                                     
কলকাতায় পরিবেশক/প্রাপ্তিস্থান
রিতা ইন্টারন্যাশনাল
৩৬, পি.এন. ব্যানার্জি রোড, কলকাতা
ফোনঃ ২৫১৩৮৩৫৯, ৯৮৩০৪৩৯৬৭৯, +৯১৯৮৩০৪৩৯৬৭৯


C++ programming language part: 55 Base Class Initialization


Base Class Initialization


In the following program, the bookself class is inherited from the furniture. Hence, an object of the bookself class includes the member of the furniture class. So, the bookself class constructor must initialize not only its member, but also the base class member. to initialize the member of furniture class, the constructir of the furniture class before the bookself class data members are initialized. keep it mind that when an object of derived class is created, the base class constructor is executed before the derived class constructor. Destructors are executed in the reverse order.

Program 42_4
            //inherit.demo
             //Scope resulation with overidden
             class furniture             //class defined
{private:
            int color;
            int width,height;

            public:
            furniture()        // dafult constructor
{ color=width=height=0;}
             furniture(int C,int W,int H)     // constructor
                { color=C;
                  width=W;
                  height=H;  }

             void data_out()
            {cout<<" The color is "<
             cout<<" The width is "<
             cout<<" The height is "<
             };
            class bookshelf:public furniture
            {  private:
               int self_no;               // member data
               public:
               bookshelf(int S,int C,int W,int H):furniture(C,W,H)
           {  self_no=S;  }
           
void data_out()
             {furniture::data_out();     // Scope Resolution Operator
               cout<<" Number of selves are "<
            };
            void main()
            {bookshelf A(5,2,7,8);             // A is called object

             A.data_out(); }




Part- 86 assign the content of twostring



জ্ঞানকোষ প্রকাশনী
৩৮/২-ক, বাংলাবাজার (২য় তলা), ঢাকা।
       ফোনঃ ৭১১৮৪৪৩, ৮১১২৪৪১, ৮৬২৩২৫১.         
                                                     
কলকাতায় পরিবেশক/প্রাপ্তিস্থান
রিতা ইন্টারন্যাশনাল
৩৬, পি.এন. ব্যানার্জি রোড, কলকাতা
ফোনঃ ২৫১৩৮৩৫৯, ৯৮৩০৪৩৯৬৭৯, +৯১৯৮৩০৪৩৯৬৭৯