/*File:  SentinelLoop01.cpp
This C++ program illustrates the use of a sentinel loop.
Typical screen output from this program follows: 

Enter a grade or -1 to quit.
20.0
Enter a grade or -1 to quit.
40.0
Enter a grade or -1 to quit.
60.0
Enter a grade or -1 to quit.
-1
Average = 40
**********************************************************/

#include <iostream>
using namespace std;

class SentinelLoop01{ 
  public:
  static void classMain(){
    SentinelLoop01* ptrToObject = new SentinelLoop01();
    ptrToObject -> doSomething();
  }//End classMain function
  //-----------------------------------------------------//

  //An instance function of the SentinelLoop01 class
  void doSomething(){
    int count = 0;
    double sum = 0;
    cout << "Enter a grade or -1 to quit." << endl;
    //Do a priming read
    double temp = 0;
    cin >> temp;

    while(temp != -1.0){
      count = count + 1;
      sum = sum + temp;
      cout << "Enter a grade or -1 to quit." << endl;
      cin >> temp;
    }//end while loop

    if(count != 0){
      cout << "Average = " << sum/count << endl;
    }//end if

  }//end doSomething function
};//End SentinelLoop01 class
//-------------------------------------------------------//

int main(){
  SentinelLoop01::classMain();
  return 0;
}//end main

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