Question

I have a method that receives an array and then stores this in the NSObject properties.

- (void)updatePoints:(NSArray *)pointArrayPassed
{
    pointArray = pointArrayPassed;
    pointCount= pointArray.count;
}

The following code works but obviously keeps the pointer of pointArrayPassed so when I can that it reflects down the call stack. However if I use a copy of the pointArrayPassed then the app starts to leak heavily!

Is there a way in the function to pass just the values as such instead of the pointer?

Answer 1

You can’t just keep sticking copies in an iVar without releasing the current object. Otherwise you’ve lost the pointer to which you can send the release message – which is why it leaks all over the place.

This is a better replacement.

- (void)updatePoints:(NSArray *)pointArrayPassed
{
    if (pointArray == pointArrayPassed) {
        //the new array is the same as the current one. Do nothing
        return;
    }
    [pointArray release];
    pointArray = [pointArrayPassed copy];
    pointCount = pointArray.count;

}

But it’s not the most elegant way of doing it.

A better way is to declare pointArray as an property with copy as its memory management semantic (which is obvious as you have a mutable/immutable class cluster). And have a separate method called -pointCount which returns the count when required.