How to store enum values in a NSMutableArray

Question

My problem is since an enum in objective-c essentially is an int value, I am not able to store it in a NSMutableArray. Apparently NSMutableArray won't take any c-data types like an int.

Is there any common way to achieve this ?

typedef enum 
{
    green,
    blue,
    red

} MyColors;


NSMutableArray *list = [[NSMutableArray alloc] initWithObjects:
                             green,
                             blue,
                             red,
                             nil];

//Get enum value back out
MyColors greenColor = [list objectAtIndex:0];

score 66 · Accepted Answer · answered Mar 21 '10 at 15:36

66

Wrap the enum value in an NSNumber before putting it in the array:

NSNumber *greenColor = [NSNumber numberWithInt:green];
NSNumber *redColor = [NSNumber numberWithInt:red];
NSNumber *blueColor = [NSNumber numberWithInt:blue];
NSMutableArray *list = [[NSMutableArray alloc] initWithObjects:
                             greenColor,
                             blueColor,
                             redColor,
                             nil];

And retrieve it like this:

MyColors theGreenColor = [[list objectAtIndex:0] intValue];

answered Mar 21 '10 at 15:36

indragie

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1

Generally this should be safe, but there are cases when it is not, since enums can be represented internally as a variety of different types. See this answer for an alternative http://stackoverflow.com/questions/1187112/cocoa-dictionary-with-enum-keys/1187901#1187901 – DougW Jul 20 '11 at 18:11

score 23 · Answer 2 · edited Feb 05 '15 at 13:10

23

A modern answer might look like:

NSMutableArray *list = 
 [NSMutableArray arrayWithArray:@[@(green), @(red), @(blue)]];

and:

MyColors theGreenColor = ((NSInteger*)list[0]).intValue;

edited Feb 05 '15 at 13:10

Alex Cio

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answered Apr 20 '14 at 18:17

Pat

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2

MyColors theGreenColor = ((NSInteger*)list[0]).intValue; Can be replaced by MyColors theGreenColor = (MyColors)[list[0] intValue]; – Haider Jan 30 '16 at 07:49

score 10 · Answer 3 · answered Apr 18 '10 at 00:42

10

Macatomy's answer is correct. But instead of NSNumber I would suggest you use NSValue. That is its purpose in life.

answered Apr 18 '10 at 00:42

nicktmro

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score 7 · Answer 4 · edited Feb 05 '15 at 13:10

7

NSMutableArray *corners = [[NSMutableArray alloc] initWithObjects:
                           @(Right), 
                           @(Top), 
                           @(Left), 
                           @(Bottom), nil];
Corner cornerType = [corner[0] intValue];

edited Feb 05 '15 at 13:10

Alex Cio

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answered Oct 14 '14 at 06:38

Tai Le

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Thomas Zoechling · Answer 5 · 2010-03-21T16:18:26.040

2

You can wrap your enum values in a NSNumber object:

[NSNumber numberWithInt:green];

edited Mar 21 '10 at 16:18

answered Mar 21 '10 at 15:33

Thomas Zoechling

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score 0 · Answer 6 · answered Feb 05 '15 at 13:12

0

To go with NSNumber should be the right way normally. In some cases it can be useful to use them as NSString so in this case you could use this line of code:

[@(MyEnum) stringValue];

answered Feb 05 '15 at 13:12

Alex Cio

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How to store enum values in a NSMutableArray

6 Answers6

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