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()
{
 

 /***************************************
  ******** HarfMi() ve RakaMi() *********
  ***************************************/
 char Ch;
 for (;;)
 {
  cout << "Bir karakter giriniz = ";
  cin >> Ch;
  if (HarfMi(Ch))   //fonksiyon cagirimina dikkat edin
   cout << "Harf\n";
  else if (RakamMi(Ch))  //fonksiyon cagirimina dikkat edin
   cout << "Rakam\n";
  else
   cout << "Bilinmeyen karakter\n";
 }
}