Returning multiple values from a method in Objective-C

user_200567 0
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I asked a similar question, but I couldn't get it working exactly. I'm building an iPhone app, and there is a method that I want called from different files. I figured the easiest way would simply be to make a method in another file, and call the method from the other files.

Here are some problems. I need to return multiple values from the method, after passing it multiple values. For example, I'm passing it: (int, int, int, string, string). And it needs to return all of those values, after they have been changed. Someone showed me this code:

- (NSDictionary *)EndOfTurn:(int)varTurns withFatness:(int)varFatness
{
    varTurns--;

    if (varTurns <= 0) {
        varFatness = varFatness - 5;
    }
    else {
        varFatness += 2;
    }

    return [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithInt:varFatness], @"FATNESS", [NSNumber numberWithInt:varTurns], @"TURNS", nil];

}

However, this code doesn't work, and I need some more information to really understand it. Let's assuming I'm passing it these values:

int varMoney;
int varNumSheep;
int varNumShepherds;
NSString *test1;
NSString *test2;

So I need to get all of these values back from the method.

How do I declare this in the header file? This should be in an Objective-C file, but could you give me the code for the entire file so I can see where it would go with the @implementation and @end, whatnot. Also, how would I call this method?

return-value objective-c iphone
6 Answers

If you only need to return primitive values, then returning a struct may be the optimal solution. You get compile-time error checking (e.g. as opposed to an NSDictionary where you could attempt to read an invalid key), while not requiring all the code/files involved in creating a class.

typedef struct myStruct {
  int varMoney;
  int varNumSheep;
  int varNumShepherds;
} myStruct;

Apple uses structs in many of their methods too (e.g. CGPoint, CGRect).

The reason this won't work with objects is because ARC forbids this.

user_356900
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