Question

I’ll keep this short and sweet, because I’m sure it is something simple that I’m missing. I’m trying to get the count for an NSMutableArray that can contain a variable number of objects (id numbers). The array is being created from JSon data & the array itself is created perfectly, regardless of whether there is a single object, or a thousand.

With regards to getting the count, If the array contains more than 1 object, everything works fine & dandy & count is returned successfully. However, if the array only has a single object/id number… the app crashes with -[NSCFString count]: error.

Here is the code I am using:

[request setCompletionBlock:^(void)
 {
     NSString *responseCurrent = [request responseString];
     NSMutableArray *json = [responseCurrent JSONValue];
     NSMutableArray *currentList = [[json valueForKeyPath:@"groupTO"] valueForKeyPath:@"currentList"];

     NSMutableArray *idNumArr = [[NSMutableArray alloc]init];
     idNumArr = [currentList valueForKey:@"idNumber"];
     debug(@"THIS IS ID ARRAY:  %@",idNumArr);

     debug(@"THIS IS COUNT OF THE ID ARRAY:  %@",[idNumArr count]);

     //  Ive also tried this to get the count, with no variation in results

     //  int countOfidNums = [idNumArr count];
     //  debug(@"count of arr:  %d",countOfidNums); 

I need to get this count to implement conditions to deal with other issues that arise from occurrences when this array only contains a single object.

I’m assuming the issue is stemming from the fact that objects in the array are strings, and when there is a single object, it is just coming as a string with no separating commas??? maybe??? help!!!!

ALSO: not sure if it makes a difference, but I am using ARC.

Answer 1

The problem here is that when you get to that line, idNumArr isn’t an array, it’s a string. If you don’t believe me, print out [idNumArr class] just before that, or step in with the debugger.

 NSMutableArray *idNumArr = [[NSMutableArray alloc]init];
 idNumArr = [currentList valueForKey:@"idNumber"];

[currentList valueForKey:@"idNumber"] is evidently returning a string (and there’s no reason to allocate the array immediately before that assignment. You probably want:

 NSMutableArray *idNumArr = [[NSMutableArray alloc]init];
 [idNumArr addObject:[currentList valueForKey:@"idNumber"]];