Source of count_digits.cpp

Structures and functions

  1: /** @file count_digits.cpp
  2: Counts the number of digits in a positive integer.
  3: */

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

  8: #include "utilities.h"
  9: using Scobey::Pause;
 10: using Scobey::ReadInt;
 11: using Scobey::userSaysYes;

 13: int numberOfDigits
 14: (
 15:     int n //in
 16: )
 17: /**<
 18: Compute the number of digits in a positive integer.
 19: @return The number of digits in the integer n.
 20: @param n The integer whose digits are to be counted.
 21: @post n has been initialized with a positive integer.
 22: @post No other side effects.
 23: */
 24: {
 25:     if (n < 10)
 26:         return 1;
 27:     else
 28:         return 1 + numberOfDigits(n / 10);
 29: }

 31: int main()
 32: {
 33:     cout << "\nThis program reads in a positive integer and then "
 34:         "computes\nand prints out the number of digits it contains.\n";
 35:     Pause();

 37:     do
 38:     {
 39:         int n;
 40:         ReadInt("Enter a positive integer: ", n);
 41:         cout << "The number of digits in " << n
 42:             << " is " << numberOfDigits(n) << ".\n\n";
 43:     }
 44:     while (userSaysYes("Do it again?"));
 45: }