objective c - Cannot add items to an NSMutableArray ivar

Question

My goal is to add a string to array, and I do that in a method which I call.

In this method, I get a null value in the array, and don't know why. I have this at the start of my class:

NSMutableArray *listOfEvents;

and a method which I call on each event:

-(void)EventList
{
    [listOfEvents addObject:@"ran"];
    NSLog(@"%@", listOfEvents);     
}

I get (null) in the log.

If I put the array definition NSMutableArray *listOfEvents; in the function body, I get the string value @"ran", each time, so the array always has only one value, instead of having many strings named @"ran".

What's wrong with this? It seems that I can't understand something about arrays, even though I have read the documents a number of times.

Answer 1

I'm assuming you haven't initialized listOfEvents.

Make sure you do listOfEvents = [[NSMutableArray alloc] init]; in your class's init method. Also make sure you release it in your class's dealloc method.