Question

So I have this method:

-(void)addLaneToRacingLanes:(UITapGestureRecognizer*)sender{


    laneDataObject *data=[self.laneDataObjects objectAtIndex:sender.view.tag];
    [self.racingLanes addObject:data];


    NSLog(@"%i",self.racingLanes.count);
    [sender.view setBackgroundColor:[UIColor yellowColor]];

}

It uses the tag from the senders view to find out which data object corresponds to that view.I’m using this to add to my racingLanes which is how I update these views, but my problem is that for some reason I cant add my laneDataObjects to my array racingLanes. Any ideas?

This is how the properties are set up:

@property (strong,nonatomic)NSArray *laneDataObjects;
@property (strong,nonatomic) NSMutableArray *racingLanes;

I have already run through the tags and they all work. The tags work such that lane 1 is tag 0 with its data object at 0, then lane 2 is tag 1 and its data is 1, so on and so forth. I already pre-tested this. And I have checked that both the laneDataObject array has been properly set up. Is it because my racingLanes isn’t using a custom getter or setter? How would I go about changing that?
Incase it matters I used

NSLog(@" %i",self.racingLanes.count);

to find out if the array was empty.

Answer 1

It is a near certainty that the racingLanes has not been initialized: since the objects that you are adding are non-nil (you’d see an exception thrown otherwise) the racingLanes must be nil then.

You need to set racingLanes to NSMutableArray in the designated initializer:

_racingLanes = [NSMutableArray array];