Using enum datatype in Objective C

Question

I have declared an enum datatype like:

typedef enum TagTypes
{
   BUTTON_TAG_1 = 1,
   BUTTON_TAG_2,
   BUTTON_TAG_3,
   NEW_TAG

}ButtonTag;

typedef enum TagType
{
   LABEL_TAG_1 = 1,
   LABEL_TAG_2,
   NEW_TAG
}LabelTag;

I wanted to find the corresponding tag of the button or label through this tag value as

(clickedbutton.tag == ButtonTag.BUTTON_TAG1) or (changingLabel.tag == LabelTag.LABEL_TAG_1)

but this syntax doesn't seem to be possible in Obj C, it throws me error saying Expected Identifier or ")"

Is there a way i can select tagNames by specifying tagDatatype like:

LabelTag.LABEL_TAG_2, ButtonTag.BUTTON_TAG2, ...

Thanks for any help

clickedbutton.tag == BUTTON_TAG1 will work, but I prefer to use it like tagName.tagValue , so that i can have same tagValues for different tag sets say tagValue "NEW_TAG" in both LabelTag and ButtonTag.

are you not getting error: redeclaration of enumerator?

Parag Bafna
– Parag Bafna

2012-03-17 10:25:17 +00:00
Commented Mar 17, 2012 at 10:25 — Parag Bafna
– Parag Bafna, Commented Mar 17, 2012 at 10:25
@ParagBafna: Is there any way to get around that error?

JohnK
– JohnK

2013-05-10 14:25:33 +00:00
Commented May 10, 2013 at 14:25 — JohnK
– JohnK, Commented May 10, 2013 at 14:25

Jesus Ramos · Accepted Answer · 2012-03-17 08:35:57Z

5

I believe it follows the same convention as it does in C where you just write

if (clickedbutton.tag == BUTTON_TAG1)

without specifying the enum type. You only have to specify the type when its a variable.

edited Mar 17, 2012 at 8:35

answered Mar 17, 2012 at 8:28

Jesus Ramos

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2 Comments

Friendtam Over a year ago

yes, that will work, but I prefer to use it like tagName.tagValue , so that i can have same tagValues for different tag sets say tagValue "NEW_TAG" in both LabelTag and ButtonTag. Thanks for your help.

Nick Weaver Over a year ago

@Prabhakaran Paulthiravium since there is already a sufficient answer, I'd like to add that a tag is an integer typ. So all you've got to do is to initialize your buttons properly: button1.tag = BUTTON_TAG_1. And since you're using an enum you may like rename the tag's names to something more meaningful, else you're trading a number for a symbol named as a number.

MrMage · Accepted Answer · 2012-03-17 10:20:52Z

0

Have a look at Apple's headers. They simply prefix all enum entries with the enum's name, e.g. UIViewAnimationCurveEaseInOut in the enum UIViewAnimationCurve. I suggest you do the same.

answered Mar 17, 2012 at 10:20

MrMage

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Comments

HelmiB · Accepted Answer · 2012-03-17 10:26:51Z

0

you may use switch-case

switch(LabelTag)
{
   case : LABEL_TAG_1

   break;

   case : LABEL_TAG_2

   break;
}

answered Mar 17, 2012 at 10:26

HelmiB

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Comments

nielsbot · Accepted Answer · 2012-03-17 22:25:26Z

0

If you really want to use the form of LabelTag::LABEL_TAG_2 you can use objective-c++ mode (change your file extension to .mm) and do this:

class FirstEnum
{
    public: 
    enum { a, b, c } ;
} ;

class SecondEnum
{
    public:
    enum { a, b, c } ;
} ;

Then in your code can can refer to LabelTag::a for example.

answered Mar 17, 2012 at 22:25

nielsbot

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