Question

I’m getting a “Potential leak” message upon doing an Analyze run of this code – which works perfectly well by the way, with no errors or crashes (its just a simple UINavigationController/TableView bit.)

The full message I get is: “Potential leak of an object allocated and stored into ‘tempKey'”

It doesn’t make sense to me – can anyone see it?

  - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // create a tempKey String var, which will store the clicked-artist's name 

    // -- this here is the line the compiler says the error is in:
    NSString *tempKey = [[NSString alloc] init];


    if ([ArtisticStaffNames objectAtIndex:indexPath.row] == @"Jeff Smith") 
        tempKey = @"Jeff";
    else if ([ArtisticStaffNames objectAtIndex:indexPath.row] == @"Dan Jones")
        tempKey = @"Dan";
    else if ([ArtisticStaffNames objectAtIndex:indexPath.row] == @"Matt Low")
        tempKey = @"Mat";
    else if ([ArtisticStaffNames objectAtIndex:indexPath.row] == @"Lisa Jennings")
        tempKey = @"Lis";
    else if ([ArtisticStaffNames objectAtIndex:indexPath.row] == @"Michael Bluarique")
        tempKey = @"Mike";

    artisticStaffDetailVC *artStaffVC = [[artisticStaffDetailVC alloc] initWithNibName: @"artisticStaffDetailVC" bundle:nil];
    artStaffVC.key = tempKey;

    [tempKey release];

    // Sets the text of the BACK button on next screen to "back":
    // alloc a UIBarButtonItem:
    UIBarButtonItem *backButton = [[UIBarButtonItem alloc] init];
    backButton.title = @"Staff";

    self.navigationItem.backBarButtonItem = backButton;
    [backButton release];

    // Pushes the next view/screen on:
    [self.navigationController pushViewController:artStaffVC animated:YES];
    [artStaffVC.key release];

}

Answer 1

The analyzer is correct. If you do this:

NSString* someString = [[NSString alloc] init];

You have a pointer to an NSString that you own. If you then do this:

someString = @"Blah";

You have assigned someString to point to a new NSString object, and leaked the first. That line does not simply change the existing string’s contents. This is exactly what you’re doing with your tempKey.