Question

I am trying to print/access my (double) value from a JSON call and get:

[Event latitude]: unrecognized selector sent to instance 0x8d09970

When accessing a string value from the same object, it prints just fine. In the debugger, I see my values and event.latitude is mapped as an NSCFNumber from a double. I don’t know if this is just me not casting or declaring latitude properly, or is something not mapping right for that value. Strings work

Here is some code:

event.h
@interface Event : NSObject  {
    NSNumber    *latitude;
}

@property (nonatomic, retain) NSNumber *latitude;
@end

ViewController.m snippet

Event *event = (Event *)[eventsArray objectAtIndex:indexPath.row];

static NSNumberFormatter *numberFormatter;
if (numberFormatter == nil) {
    numberFormatter = [[NSNumberFormatter alloc] init];
    [numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
    [numberFormatter setMaximumFractionDigits:3];
}
NSLog(@"Event - %@", event.name );  //This works just fine
NSLog(@"Event - %@", event.latitude );  //This is where I am testing different ways of accessing the latitude
NSLog(@"Event - %@", [numberFormatter stringFromNumber:[event latitude]] );
//NSLog(@"Event - %@", [[event latitude] stringValue] );
NSString *coordinatesString = [[NSString alloc] initWithFormat:@"Lat:%@, Lon:%@",
                               [numberFormatter stringFromNumber:[event latitude]],
                               [numberFormatter stringFromNumber:[event longitude]]];

Answer 1

That’s definitely not about casting.

The exception you’re getting is due to the lack of a latitude implementation, that you probably forgot or mistyped.

Did you @synthesize the property in the Event.m implementation file?