Urgent! Help Needed

I have an assignment that is due by midnight tonight. I have completed 2 of 3 programs to write, and I have a very unusual (to me) problem. Here is the Header file:

Code:

---

// interface file for the counter class -- counter.h

#ifndef COUNTER_H
#define COUNTER_H

class Counter
{
  public:

  // constructors
  Counter();

  // modifier methods
  void clear();
  void inc();
  void dec();

  // accessor methods
  int value() const;

  private:
  int count;
};

#endif

---

The implementation file:

Code:

---

// Implementation file for the counter class -- counter.cc

#include<iostream>
#include<string>
using namespace std;

#include "counter.h"

//**************************************************************************
// Constructor to set the initial count to zero.
//**************************************************************************
Counter::Counter() { count = 0; }

//*************************************************************************
// Function to clear the counter.
//*************************************************************************
void Counter::clear() { count = 0; }

//*************************************************************************
// Function to increment the counter by one.
//*************************************************************************
void Counter::inc()
{
  count++;
  cout << "INCREMENT" << endl;
}

//*************************************************************************
// Function to decrement the counter by one.
// - If the counter is already at zero, an error message is returned.
//*************************************************************************
void Counter::dec()
{
  if(count == 0)
      cout << "Error: Cannot go less than zero." << endl;
  else
      count = count - 1;
}
//*************************************************************************
// Function to return the counter's value.
//*************************************************************************
int Counter::value() const { return count; }

---

and the Client program:

Code:

---

//**************************************************************************
// Program to determine how many of each digit occurs in a string.
//
// Written by Alan Johnson
// 001085624
// April 14th, 2004
//**************************************************************************

#include<string>
#include<iostream>
using namespace std;

#include "counter.h"

int main()
{
  string input;
 
  cout << "Enter a string (Ctrl-D to stop): ";
  getline(cin, input);
 
  if(!cin.eof())
  {
      while(!cin.eof())
      {
        Counter A[10];

        for(int i = 0; i < 10; i++)
            for(int k = 0; k < input.length(); k++)
            {
              // HERE IS WHERE THE PROBLEM LIES
              if((input.at(k)) == i)
                  A[i].inc();
            }
        for(int j = 0; j < 10; j++)
        {
            cout << A[j].value() << " ";
            A[j].clear();
        }

        cout << endl << "Enter a string (Ctrl-D to stop): ";
        getline(cin, input);
      }
     
      cout << endl;
      return 0;
  }
  else
      cout << endl;
      return 0;
}

---

I bolded the comment where the problem is.

For some reason, when the input.at(k) DOES equal i, It doesn't actually go into the if statement. I tested it out, and no matter what the user puts in it does not make the if statement true. I searched on the internet high and low, and nothing has helped me. I would really very much appreciate it if anyone can help.

Thanks!

try doing (i + '0') instead of i

Eureka! Thank you very much. Such a simple solution, as I thought it would be. So if you don't mind, I was just curious why it works that way?

Thanks again!

>I was just curious why it works that way?
0 + '0' == '0'
1 + '0' == '1'
2 + '0' == '2'
etc...

[edit]
Typo
[/edit]

You can't correctly compare the integer i to the character returned from at() without converting them to the same type. Luckily, characters are represented by codes and all of the characters that represent numbers 0-9 come in order in those codes. That creates an easy way to convert a single digit integer to its character equivalent. Just take the code for '0' (whatever it is) and if you add 4 to it you'll get the code for '4'. Of course, that only works for single digit positive integers. If you have more complicated numbers, you'd have to convert the entire string to a number first (maybe using atoi or atof) and then compare the numbers.

> 2 + '0' == '3'
:) You sure?