[Tutor] enumeration in C++

[Paul Sidorsky]

Nicole Seitz wrote:

> What's enumeration  good for? Can someone give me a few examples when I would
> use enumeration?Years ago, when I was TRYING to learn C, I came across enum,
> but never found out its purpose.

Enumeration is very handy for things like mode or state constants, for
example:

typedef enum
{
    StBeginning, StMiddle, StMiddle2, StEnd, NUMSTATES
} states;

or

typedef enum
{
    ModeIcon, ModeSmallIcon, ModeList, ModeDetails, NUMMODES
} modes;

I always like to include the total in there since then if I insert new
modes/states it gets updated automatically.

In C++ (if I remember correctly) you also get type protection if a
variable is defined to be an enum, for example:

modes currentmode;
...
currentmode = ModeSmallIcon; // OK
...
currentmode = 2; // Illegal, even though 2==ModeList

Interestingly enough, despite having grown up with C for over a decade,
I haven't missed enumerations in Python.  But they can be rather handy
sometimes.

-- 
======================================================================
Paul Sidorsky                                          Calgary, Canada
paulsid@shaw.ca                        http://members.shaw.ca/paulsid/