Question

I have to maintain a code of somebody. The code opens a thread. The thread worker function in iOS (and any other language I know of) accepts only one parameter. In order to overcome this, the code creates an array, adds all the parameters into an array and passes it into the thread. Here is the code.

NSArray* params = [[NSArray alloc] initWithObjects: mainView, actionFlag, nil];
[self performSelectorOnMainThread:@selector(updateWorker:) withObject:params waitUntilDone:NO];

And the function is called this way

-(void)updateWorker:(NSArray*)params
{
    UIView* view = [params objectAtIndex:0];
    bool actionFlag = ((NSNumber*)[params objectAtIndex:1]).boolValue;
    /* do stuff with view and actionFlag */
}

I have a gut feeling that this is very wrong at so many levels but cannot built a valid argument for this case.

What are the drawbacks of passing number of arguments as an array?

Answer 1

Most of them are future updates,
Some cases (not so rare) may happen:

• Addition of new parameters to the array
• changing the order of elements in the array
• removing elements in the array
• problems when releasing and retaining elements in the array (not ARC)

One point to note here, is that all of these cases will be hard to debug, since you will be moving from one thread to the other