enum Values to NSString (iOS)

Question

I have an enum holding several values:

enum {value1, value2, value3} myValue;

In a certain point in my app, I wish to check which value of

Answer 1

Here is a plug-and-play solution that you can extend with a simple copy and paste of your EXISTING definitions.

I hope you all find it useful, as I have found useful so many other StackOverflow solutions.

- (NSString*) enumItemNameForPrefix:(NSString*)enumPrefix item:(int)enumItem {
NSString* enumList = nil;
if ([enumPrefix isEqualToString:@"[Add Your Enum Name Here"]) {
    // Instructions:
    // 1) leave all code as is (it's good reference and won't conflict)
    // 2) add your own enums below as follows:
    //    2.1) duplicate the LAST else block below and add as many enums as you like
    //    2.2) Copy then Paste your list, including carraige returns
    //    2.3) add a back slash at the end of each line to concatenate the broken string
    // 3) your are done.
}
else if ([enumPrefix isEqualToString:@"ExampleNonExplicitType"]) {
    enumList = @" \
    ExampleNonExplicitTypeNEItemName1, \
    ExampleNonExplicitTypeNEItemName2, \
    ExampleNonExplicitTypeNEItemName3 \
    ";
}
else if ([enumPrefix isEqualToString:@"ExampleExplicitAssignsType"]) {
    enumList = @" \
    ExampleExplicitAssignsTypeEAItemName1 = 1, \
    ExampleExplicitAssignsTypeEAItemName2 = 2, \
    ExampleExplicitAssignsTypeEAItemName3 = 4 \
    ";
}
else if ([enumPrefix isEqualToString:@"[Duplicate and Add Your Enum Name Here #1"]) {
    // Instructions:
    // 1) duplicate this else block and add as many enums as you like
    // 2) Paste your list, including carraige returns
    // 3) add a back slash at the end of each line to continue/concatenate the broken string
    enumList = @" \
    [Replace only this line: Paste your Enum Definition List Here] \
    ";
}

// parse it
int implicitIndex = 0;
NSString* itemKey = nil;
NSString* itemValue = nil;
NSArray* enumArray = [enumList componentsSeparatedByString:@","];
NSMutableDictionary* enumDict = [[[NSMutableDictionary alloc] initWithCapacity:enumArray.count] autorelease];

for (NSString* itemPair in enumArray) {
    NSArray* itemPairArray = [itemPair componentsSeparatedByString:@"="];
    itemValue = [[itemPairArray objectAtIndex:0] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    itemKey = [NSString stringWithFormat:@"%d", implicitIndex];
    if (itemPairArray.count > 1)
        itemKey = [[itemPairArray lastObject] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    [enumDict setValue:itemValue forKey:itemKey];
    implicitIndex++;
}

// return value with or without prefix
NSString* withPrefix = [enumDict valueForKey:[NSString stringWithFormat:@"%d", enumItem]];
NSString* withoutPrefix = [withPrefix stringByReplacingOccurrencesOfString:enumPrefix withString:@""];
NSString* outValue = (0 ? withPrefix : withoutPrefix);
if (0) NSLog(@"enum:%@ item:%d retVal:%@ dict:%@", enumPrefix, enumItem, outValue, enumDict);
return outValue;
}

Here are the example declarations:

typedef enum _type1 {
ExampleNonExplicitTypeNEItemName1, 
ExampleNonExplicitTypeNEItemName2, 
ExampleNonExplicitTypeNEItemName3
} ExampleNonExplicitType;

typedef enum _type2 {
ExampleExplicitAssignsTypeEAItemName1 = 1, 
ExampleExplicitAssignsTypeEAItemName2 = 2, 
ExampleExplicitAssignsTypeEAItemName3 = 4
} ExampleExplicitAssignsType;

Here is an example call:

NSLog(@"EXAMPLE:  type1:%@  type2:%@ ", [self enumItemNameForPrefix:@"ExampleNonExplicitType" item:ExampleNonExplicitTypeNEItemName2], [self enumItemNameForPrefix:@"ExampleExplicitAssignsType" item:ExampleExplicitAssignsTypeEAItemName3]);

Enjoy! ;-)

Answer 2

Here is working code https://github.com/ndpiparava/ObjcEnumString

//1st Approach
#define enumString(arg) (@""#arg)

//2nd Approach

+(NSString *)secondApproach_convertEnumToString:(StudentProgressReport)status {

    char *str = calloc(sizeof(kgood)+1, sizeof(char));
    int  goodsASInteger = NSSwapInt((unsigned int)kgood);
    memcpy(str, (const void*)&goodsASInteger, sizeof(goodsASInteger));
    NSLog(@"%s", str);
    NSString *enumString = [NSString stringWithUTF8String:str];
    free(str);

    return enumString;
}

//Third Approcah to enum to string
NSString *const kNitin = @"Nitin";
NSString *const kSara = @"Sara";


typedef NS_ENUM(NSUInteger, Name) {
    NameNitin,
    NameSara,
};

+ (NSString *)thirdApproach_convertEnumToString :(Name)weekday {

    __strong NSString **pointer = (NSString **)&kNitin;
    pointer +=weekday;
    return *pointer;
}

Answer 3

I will introduce is the way I use, and it looks better than previous answer.(I thinks)

I would like to illustrate with UIImageOrientation for easy understanding.

typedef enum {
    UIImageOrientationUp = 0,            // default orientation, set to 0 so that it always starts from 0
    UIImageOrientationDown,          // 180 deg rotation
    UIImageOrientationLeft,          // 90 deg CCW
    UIImageOrientationRight,         // 90 deg CW
    UIImageOrientationUpMirrored,    // as above but image mirrored along other axis. horizontal flip
    UIImageOrientationDownMirrored,  // horizontal flip
    UIImageOrientationLeftMirrored,  // vertical flip
    UIImageOrientationRightMirrored, // vertical flip
} UIImageOrientation;

create a method like:

NSString *stringWithUIImageOrientation(UIImageOrientation input) {
    NSArray *arr = @[
    @"UIImageOrientationUp",            // default orientation
    @"UIImageOrientationDown",          // 180 deg rotation
    @"UIImageOrientationLeft",          // 90 deg CCW
    @"UIImageOrientationRight",         // 90 deg CW
    @"UIImageOrientationUpMirrored",    // as above but image mirrored along other axis. horizontal flip
    @"UIImageOrientationDownMirrored",  // horizontal flip
    @"UIImageOrientationLeftMirrored",  // vertical flip
    @"UIImageOrientationRightMirrored", // vertical flip
    ];
    return (NSString *)[arr objectAtIndex:input];
}

All you have to do is :

1. name your function.

2. copy contents of enum and paste that between NSArray *arr = @[ and ]; return (NSString *)[arr objectAtIndex:input];

3. put some @ , " , and comma

4. PROFIT!!!!

Answer 4

This will be validated by compiler, so you won't mix up indices accidentally.

NSDictionary *stateStrings =
 @{
   @(MCSessionStateNotConnected) : @"MCSessionStateNotConnected",
   @(MCSessionStateConnecting) : @"MCSessionStateConnecting",
   @(MCSessionStateConnected) : @"MCSessionStateConnected",
  };
NSString *stateString = [stateStrings objectForKey:@(state)];

var stateStrings: [MCSessionState: String] = [
    MCSessionState.NotConnected : "MCSessionState.NotConnected",
    MCSessionState.Connecting : "MCSessionState.Connecting",
    MCSessionState.Connected : "MCSessionState.Connected"
]
var stateString = stateStrings[MCSessionState.Connected]

Answer 5

This is answered here: a few suggestions on implementation

The bottom line is Objective-C is using a regular, old C enum, which is just a glorified set of integers.

Given an enum like this:

typedef enum { a, b, c } FirstThreeAlpha;

Your method would look like this:

- (NSString*) convertToString:(FirstThreeAlpha) whichAlpha {
    NSString *result = nil;

    switch(whichAlpha) {
        case a:
            result = @"a";
            break;
        case b:
            result = @"b";
            break;
        case c:
            result = @"c";
            break;

        default:
            result = @"unknown";
    }

    return result;
}

Answer 6

I didn't like putting the enum on the heap, without providing a heap function for translation. Here's what I came up with:

typedef enum {value1, value2, value3} myValue;
#define myValueString(enum) [@[@"value1",@"value2",@"value3"] objectAtIndex:enum]

This keeps the enum and string declarations close together for easy updating when needed.

Now, anywhere in the code, you can use the enum/macro like this:

myValue aVal = value2;
NSLog(@"The enum value is '%@'.", myValueString(aVal));

outputs: The enum value is 'value2'.

To guarantee the element indexes, you can always explicitly declare the start(or all) enum values.

enum {value1=0, value2=1, value3=2};