Question

C++ program

Create a Student class that contains three private data members of stududentID (int), lastName (string), firstName(string) and a static data member studentCount(int).

• Create a constructor that will take three parameters of studentID, lastName and firstName, and assign them to the private data member. Then, increase the studentCount in the constructor.
• Create a static function getStudentCount() that returns the value of studentCount.
• studentCount is used to track the number of student object has been instantiated. Initialize it to 0 outside of the class implementation.

Write a main function:

• print out the value of studentCount by using the scope resolution operator Student:: and getStuentCount()
• instantiate two students S1 and S1 by making up the studentIDs, firstNames and lastNames.
• print outthe value of studentCount again.

Answer 1

#include<iostream>
using namespace std;
//class student
class student
{
    private:
        //data members
        int studentID;
        string lastName,firstName;
        static int studentCount;
    public: //member functions
      student(int,string,string)   ;
      static int getStudentCount();
};
//parameterized constructor
student :: student(int a,string fname,string lname)
{
   studentID = a; //assignthe a to studentID
   lastName = lname; //assign lname to lastName
   firstName = fname; //assign fname to firstName
   studentCount++; //increase the studentCount
}
//getStudentCount() method will return the studentCount
int student :: getStudentCount()
{
   return studentCount;
}
//initialize the static data member to 0
int student :: studentCount=0;
//driver program
int main()
{
   //variable declaration
   int n;
   string fname,lname;
   //call the getStudentCount() through student class name
   cout<<endl<<"Number of objects : "<<student :: getStudentCount();
   //input the student ID
   cout<<endl<<"Enter the student ID";
   cin>>n;
   //input the first name and last name
   cout<<endl<<"Enter the first name and last name";
   cin>>fname>>lname;
   //create an object through parameterized constructor
   student s1(n,fname,lname);
   //call the getStudentCount() through student class name
   cout<<endl<<"Number of objects : "<<student :: getStudentCount();
}

OUTPUT