Source of positive_average.cpp

Structures and functions

  1: //positive_average.cpp
  2: //Finds the average of all positive integer values input by
  3: //the user. Illustrates an EOF-controlled loop, and a test
  4: //after the loop to make sure the input data set was not empty.

  6: #include <iostream>
  7: using namespace std;

  9: int main()
 10: {
 11:     cout << "\nThis program computes the average of any number of "
 12:         "positive integer values.\nInput values may be positive, "
 13:         "negative, or zero, but non-positive values are\nsimply "
 14:         "ignored. Enter as many values as you like, then press the "
 15:         "Enter key.\nTo compute and display the avarage enter an "
 16:         "end-of-file and press Enter again.\n";

 18:     int i;
 19:     int numberOfPositiveIntegers = 0;
 20:     int sum = 0;
 21:     double average;

 23:     cout << "\nStart entering values on the line below:\n";
 24:     cin >> i;
 25:     while (cin)
 26:     {
 27:         if (i > 0)
 28:         {
 29:             sum = sum + i;
 30:             numberOfPositiveIntegers++;
 31:         }
 32:         cin >> i;
 33:     }

 35:     if (numberOfPositiveIntegers == 0)
 36:         cout << "No positive integers were input.\n";
 37:     else
 38:     {
 39:         average = double(sum) / double(numberOfPositiveIntegers);
 40:         cout << "The average of the "          << numberOfPositiveIntegers
 41:              << " positive integer values is " << average << ".\n";
 42:     }
 43:     cout << endl;
 44: }