Question

Q.Write a program that shows a class called gamma that keeps track of how many objects of itself there are. Each gamma object has its own identification called ID. The ID number is set equal to total of current gamma objects when an object is created.

Test you class by using the main function below.

int main()

   {

   gamma g1;

   gamma::showtotal();

   gamma g2, g3;

   gamma::showtotal();

   g1.showid();

   g2.showid();

   g3.showid();

   cout << "----------end of program----------\n";

   return 0;

   }

Runtime output

Total is 1

Total is 3

ID number is 1

ID number is 2

ID number is 3

----------end of program----------

Destroying ID number 3

Destroying ID number 2

Destroying ID number 1

C++ please

Answer 1

#include <iostream> 
using namespace std; 

//Idea is to use static variable to keep track
//of number of classes
class gamma 
{ 
    // This is to store ID
    int ID;
    
    //This is to keep track of total number
    //objects of the gamma class
    static int objCount; 
  
public:
    //Constructor
    gamma()  
    { 
        //Pre increment objCount and store in ID
        ID = ++objCount;  
    } 
    //Destructor
    ~gamma() 
    { 
        cout<<"Destroying ID number"<<ID<<"\n";
        //Pre decrementing objCount as one object is deleted
        --objCount; 
    } 
    void showid() 
    { 
        cout << "ID number is:" << ID << "\n"; 
    } 
    static void showtotal(void) 
    { 
        cout << "Total is:" << objCount<< "\n"; 
    } 
}; 

//Initializing the stact variable.
//Static variables are set to 0(by default).
int gamma::objCount;

int main()
{

   gamma g1;

   gamma::showtotal();

   gamma g2, g3;

   gamma::showtotal();

   g1.showid();

   g2.showid();

   g3.showid();

   cout << "----------end of program----------\n";

   return 0;

}

Output Screenshot:

(Note: Please refer to the screenshots of the code to understand the indentation of the code)

Code Screenshots:

gamma class:

main():