C++ Harf'mi Rakam'mı Bulma Programı

#include <iostream>
using namespace std;

bool HarfMi(char Ch){
 if ((Ch >= 'A' && Ch <= 'Z') || (Ch >= 'a' && Ch <= 'z'))
  return true;
 else
  return false;
}
bool RakamMi(char Ch){
 if (Ch>='0' && Ch<='9')
  return true;
 else
  return false;
}
void main()
{