Question

I am attempting to load up an entire array of NSManagedObjects into an NSArray, then use an integer iterator to iterate through the array when a button is tapped. xCode seems to dislike declaring the integer and NSArray in the .h, then used throughout different methods in the .m.

I was wondering what the appropriate path an experienced developer would take in solving such a problem.

The flow would be:
1. Load data into array.
2. Set label using information at index 0. int i = 0;
3. User taps button; i++, retrieve element at index 1.

and so on until the end of the array, or the user stops tapping the button.

Edited:

This is the code that works, but I feel is incorrect:

XYZViewController.h

@interface XYZViewController : UIViewController <NSFetchedResultsControllerDelegate>{
    int index;  
}

XYZViewController.m

import "XYZViewController.h"

- (void)function1{
    index = 0;
}

- (void)function2{
    index++;
}

-(void)function3{
    NSManagedObject *obj = [results objectAtIndex:index];
}

Is this actually correct? It works, but not elegant; not at all.

Answer 1

Did you declare the integer and NSArray in your .h file outside of a class? if so, it would be defined in every compilation module that includes that file, which results in multiple symbols at linking time => error.

Solution: If you need the NSArray / int only in one .m file, move them there. Otherwise declare them as extern in the .h, and define them in exactly 1 .m file, like this:

// 1.h
extern int myInt;

// 1.m
#include "1.h"
int myInt;
// Use myInt

// 2.m
#include "1.h"
// Use myInt