Help with enumerated data types.

Hello.

just got a question, why should I use enum instead of an int?

enum just gives me +1 from the predecessor I picked.
why not use a fixed number?

I can understand if im going to write out the numbers on the months of the entire year, then it can be good to get +1 instead of writing:
january = 1; february = 2; etc etc etc

but other than that, I just dont get it :P
DONT link me to another homepage where it is explaining the enum, cuz I have read that.
Give me some concrete examples.

Thx.

Err, because you want to have a set of values, not every possible integer. Like if you have a set of car models, somebody in the program might pick something that doesn't exist. I mean he can say car.model = "Aubi". If you used enums and somebody (even you by mistake) wrote car.model = Aubi then you get a compile time error. Now, you could have a list of possible options for the cars, but then you have to makes checks like if( car.mode == "Audi" || ....) which is ineffective and bug friendly.
So you use enums.
As everything, it helps you, the programmer. If you make something small and simple they are not needed. If you make something big with lots of programmers, then it is a good idea

Aight thx.

got an exercise where it says that Im going to write a menu program.
with 3 difficulty levels.
And I should use the enum to represent the 3 difficulty levels.

Using switch(), isn't the default: there for correcting my mistakes? (that will say if I didnt press 1-3)

Which do you prefer?

Code:

---

switch ( month ) {
  case 9: case 4: case 6: case 11:
    numdays = 30;
    break;
}

---

or this

Code:

---

switch ( month ) {
  case september: case april: case june: case november:
    numdays = 30;
    break;
}

---

Enums add to the readability of the code.

> enum just gives me +1 from the predecessor I picked.
> why not use a fixed number?
Not always, you can have
red = 1, amber = 2, green = 4

So why not have

Code:

---

#define red 1
#define amber 2
#define green 4

---

Enums have a measure of type safety, and would be understood by the debugger.

So for example, consider

Code:

---

enum { red = 1, amber = 2, green = 4 } traffic_t;
enum { apple, orange, banana } fruit_t;

traffic_t light = orange;  // it's a fruit, not a colour

---

would draw some comment from the compiler.

If you just had int, and a bunch of #defines, all the compiler would see is
int light = 2;

In a debugger, you're likely to see light = red (meaningful), rather than light = 0 (much harder work).

aaah okey, thx for the explanation, appriciate it =)