accessing enum members by int values

Question

I have

enum Direction { NONE = 0, LEFT, RIGHT, FORWARD };

and there is a function

void displayDirection(int dir)
{ ... }

This function will take an int value and will print the members of "Direction" according to that value. How can it be possible? Thanks in advance.

ex: if dir = 0 print NONE; if dir = 1, print RIGHT; etc.

PS: I am very new at c++.

Isn't this already covered on about a [dozen different questions](http://stackoverflow.com/search?q=%5Bc%2B%2B%5D+enum+int+convert) — WhozCraig, Oct 29 '12 at 14:22

score 3 · Answer 1 · answered Oct 29 '12 at 14:17

3

you need "string" versions of them to print... e.g. char* szArray[] = { "NONE", "LEFT", "RIGHT", "FORWARD" }; then in displayDirection reference it via szArray[dir]. bounds-checking would be appropriate as well...

answered Oct 29 '12 at 14:17

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score 2 · Answer 2 · edited Oct 29 '12 at 14:18

2

Yes, it's possible, because enum values are, under the hood, integral types. The conversion is implicit, so you should be able to directly call

displayDirection(3);  //FORWARD

However, I suggest changing the function signature to

void displayDirection(Direction dir)

edited Oct 29 '12 at 14:18

Pete Becker

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answered Oct 29 '12 at 14:14

Luchian Grigore

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I didnt understand how can it be possible with 1st function, what should be the inside of that function. And I want to do it by int parameter, i try to learn – Mustafa Oct 29 '12 at 15:01
@Mustafa how *what* can be possible? – Luchian Grigore Oct 29 '12 at 15:02
@LuchianGrigore what should be the definition of displayDirection(3) function, i think it is impossible according to other answers – Mustafa Oct 29 '12 at 16:12
@LuchianGrigore okay, how can I print "FORWARD" when I call displayDirection(3); ? – Mustafa Oct 29 '12 at 16:31
@Mustafa see http://stackoverflow.com/questions/201593/is-there-a-simple-script-to-convert-c-enum-to-string – Luchian Grigore Oct 29 '12 at 16:32

score 0 · Answer 3 · answered Oct 29 '12 at 14:19

If you want to print the text values, "NONE", "LEFT" etc, that is not directly possible.

In the compiled executable, the names have been optimised away and you can't get them back, just like you can't reference variables by name (like "dir" in your example).

So what you should do is put the names into your program by store them in a string array.

accessing enum members by int values

3 Answers3