Comments on: 4.5 — Enumerated types

By: kalvin

kalvin — Thu, 02 Feb 2012 00:33:01 +0000

Enumerations are a little confusing for me. I would better understand them if i had a practical use for them.. I know that no arithmetic operations are allowed on enum, and that since enums are an ordered set of values, you can use relational operators, and loops. this being said I guess I can see how using enum to make your program more readable might be benificial. But to really incorperate enums into your program you will have to input and output enums indirectly as you can not directly output or input enumeration data types.. So for now , i think you have to choose whether to make your program more readable with more work using enumerations, or not and save the extra programming.. Idk maybe as i learn and play with this more i will find its practicality

By: zingmars

zingmars — Thu, 26 May 2011 15:47:24 +0000

PLEASE avoid using system(“PAUSE”). use cin.get() or something but, please avoid using any system(“”) function. That way you’ll be doing favors both for yourself AND others who’re reading your code.

By: christopher11

christopher11 — Tue, 24 May 2011 02:49:12 +0000

This is what i came up with
#include
using namespace std;

enum Race
{
RACE_ORC = 1,
RACE_GOBLIN = 2,
RACE_TROLL = 3,
RACE_OGRE = 4
};

int pickRace(int race);

main()
{
int x;
cout<< "Choose your race: " << endl << "Orc(1) – Goblin(2) – Troll(3) – Ogre(4)";
cout<> x;
pickRace(x);
system(“PAUSE”);
return 0;
}

int pickRace(int race)
{
static int choice;
if(race==1)
{
choice = RACE_ORC;
}
if(race==2)
{
choice = RACE_GOBLIN;
}
if(race==3)
{
choice = RACE_TROLL;
}
if(race==4)
{
choice = RACE_OGRE;
}

if(choice==1)
{
cout<<"You picked Orc.";
}
if(choice==2)
{
cout<<"You picked Goblin.";
}
if(choice==3)
{
cout<<"You picked Troll.";
}
if(choice==4)
{
cout<<"You picked Ogre.";
}
cout<< endl;
}

By: newUser

newUser — Wed, 13 Apr 2011 02:41:30 +0000

If I had not read the comments I would have never noticed enum uses commas! May I suggest having it written in the tutorial too so it draws more attention to it?

By: sm00th_0perat0r

sm00th_0perat0r — Tue, 01 Mar 2011 23:01:46 +0000

I'm pretty sure that by explicitly defined, he means setting it equal to a value yourself, as opposed to implicitly
defined where the value would be chosen by its order in the list...

...but I could be wrong!

By: SWEngineer

SWEngineer — Sat, 22 Jan 2011 11:59:07 +0000

Simple well explained tutorial. Thanks.

By: bla

bla — Wed, 11 Aug 2010 10:48:30 +0000

I am not really sure about the meaning of questions 3a,b. Does explicit mean explicit cast in this context?

“3) True or false. Enumerators can be:
3a) explicitly assigned integer values”
that would be:

 Animal eAnimal = static_cast(5);

3b) not explicitly assigned a value
???

By: Luiwtf

Luiwtf — Thu, 05 Aug 2010 20:43:48 +0000

if (part[BODY_PART] = 0 && part[BODY_PART_FLAG] == 0)

should be:

if (part[BODY_PART] == 0 && part[BODY_PART_FLAG] == 0)

note the 2 ='s, instead of one :) the reason it works with || is because the second half comes up true as you have the == correct, as it is the first part is irrelevant. edit - meh, just noticed it's a month old :D, i suck at remembering dates :p.

By: John

John — Wed, 07 Jul 2010 16:23:13 +0000

#include 
#include 
#include 

using namespace std;

namespace BODY_PARTS
{
    const int BPMEMBERS = 2;

    enum MEMBER_TYPES
    {
        BODY_PART = 0,
        BODY_PART_FLAG = 1,
    };

    enum BODY_PARTS
    {
        HEAD = 0,
        TORSO = 1,
        ARM = 2,
        LEG = 3,
    };

    enum BODY_PART_STATUS
    {
        FINE = 0,
        SCRATCHED = 1,
        CUT = 2,
        GASHED = 3,
        BROKEN = 4,
        MANGLED = 5,
    };
}
using namespace BODY_PARTS;

void PrintBodyPartStatus(int part[BPMEMBERS])
{
    if (part[BODY_PART] = 0 && part[BODY_PART_FLAG] == 0)
    {
        cout << "Your head is fine";
    }

    else cout << part[BODY_PART] << endl << part[BODY_PART_FLAG];
}

int main()
{
    int head[BPMEMBERS];

    head[BODY_PART] = HEAD;
    head[BODY_PART_FLAG] = FINE;

    PrintBodyPartStatus(head);
    return 0;
}

I hope that is all in code !

When I run this, I get the exception in the PrintBodyPartStatus(), which prints 0 0.
And the check above the exception, is expecting a 0, 0.
What am I missing? Am I doing this wrong? It seems like a viable way to use Enums, as I’ve been using consts for EVERYTHING until I had a look at some open source game Enums.

I’m currently working on this, so don’t think I’m commenting to expect you to do it for me (which would be nice, I admit)
But I really didnt’t see the point in typing out

enum COLOURS
{
    RED,
    YELLOW,
    GREEN,
    {..}
};

where in a few less line I coult just type in

const int RED = 0;
const int YELLOW = 1;
const int GREEN = 2;
{..}

Thanks in advance

EDIT:
changing the check from && to || make it work. I’ve always wondered why OR checks work properly and AND checks don’t. (Maybe I’ve been doing those all wrong too, but I’ve always had the problem, even on simple checks.

even compound if’s don’t work very often

if(blah)
{
      if(blah blah)
      {
             Do(blah blah blah)
      }
}

Strange.

By: Shai

Shai — Thu, 08 Oct 2009 08:35:45 +0000

Great work, Alex.
Your site is better than any C++ book I know of.