Re: [Dev-C++] enum

[Bob W. <bo...@ph...>]

MessageIoannis,
    Absolutely correct, but when you assign a value to an enumerated =
element, it practically destroys or greatly limits the ability to use =
the enumerated elements in a for loop or switch statement. =20

  Why you can't use them in a switch statement? In fact a switch =
statement is one of the common uses for enums.
If you will re-read what I wrote, you will see I did not say you could =
not use them, however, if you write  something like this:
  enum animals { cat, dog, horse =3D 7, rabbit =3D 3, pig, cow, mule =3D =
30 }
which is a legal statement, and you write a for loop like this:

  int counter;
  for (counter =3D cat - 1; counter < mule; counter++)
  {
       std::cout << "counter =3D " << counter << "\n"
  };
The loop will execute 30 times even though there are only seven =
elements. It works, but it can lead to unexpected results if you think =
is it only going to loop seven times because there are only seve =
elements. If no value assignments are given to the set of elements, the =
loop works as a novice might expect. It is certainly possible that there =
is an operation that must not be performed for a cat, once for a dog, =
seven times for a horse, three times for a pig, four times for a cow, =
and 30 times for a mule, and, in that case, you could make the for work. =
However, I doubt that the resulting code would be a decypherable as =
using conditional switching to call an offset function as follows:


  #include <iostream.h>
  #include <stdlib.h>

  enum animals { cat, dog, horse =3D 7, rabbit =3D 3, pig, cow, mule =3D =
30 };

  int DoItNow (int NumOfTimes)
  {
      for (int i =3D cat; i < NumOfTimes; i++)
      {
          // do something
          std::cout << "did something " << i + 1 << " times\n";
      }
  };

  int main()
  {
      unsigned short int whichAnimal;
      std::cout << "Enter a number between "=20
                << cat << " and " << mule << ": ";
      std::cin >> whichAnimal;
      std::cout << "Hey! It's a";
      switch (whichAnimal)
      {
      case cat : std::cout << " cat!\n";
                 DoItNow(cat); // do it once
                 break;

      case dog : std::cout << " dog!\n";
                 DoItNow(dog); // do it twice
                 break;

      case horse : std::cout << " horse!\n";
                 DoItNow(horse); // do it seven times
                 break;

      case rabbit : std::cout << " rabbit!\n";
                 DoItNow(rabbit); // do it three times
                 break;

      case pig : std::cout << " pig!\n";
                 DoItNow(pig); // do it four times
                 break;

      case cow : std::cout << " cow!\n";
                 DoItNow(cow); // do it five times
                 break;

      case mule : std::cout << " mule!\n";
                 DoItNow(mule); // do it 30 times
                 break;

      default:
          std::cout << "n unidentified animal!\n"; // fall through
      }
     =20
      system("pause");
      return 0;
  }
To me, it is much easier to see that the programmer wants an activity to =
take place seven times if the value is horse than using whichAnimal in =
the for loop above. Obviously the code is not as tight, but it is =
certainly more transparent which is a good thing.=20

Regards,

Bob