Question

In the code below:

- (void)viewDidLoad {

    NSArray *array = [[NSArray alloc] initWithObjects: @"Browny", @"Andy", @"Chiki", @"Gillu",
                      @"SnowLeopard", @"Lion", @"Tiger", @"SiberianTiger", nil ];
    self.pickerData = array;
    [array release];    

}

if I change in above self.pickerData to pickerData, the program crashes with EXC_BAD_ACCESS signal received.

I thought for member variables/properties of the object using keyword self was optional?
Any hints, why I need self here, even though pickerData is a member variable of the class?

Answer 1

To wrap it up in one answer instead of dotted across the other answers.

When you call

self.pickerData = array; 

this is compiled to

[self setPickerData:array];

If you @sythesize pickerData the implementation will do something similar to:

- (void)setPickerData:(NSArray *)_pickerData;
{
    if (pickerData != _pickerData) {
        [pickerData release];
        pickerData = [_pickerData retain];
    }
}

So the difference is that self.pickerData = array will go through the setter that will do the correct memory management whereas pickerData = array assigns the value directly.