Short and useful Objective-C snippets?

Question

Since XCode 4, there is now a Code Snippets section which offers the snippets via auto-complete when typing. I'd be very interested in snippets you all have stored in there. What snippets save you the most time (and why)?

Please only post actual snippets (meaning no snarky "don't need no stinkin' snippets", and no "i love snippets that do <XYZ>"), and only snippets that are short and sweet (i.e. no more than ~20 lines at the most...). If a snippet is not obviously useful, also explain why you think it is. ;)

Answer 1

I don't if this counts but I always use this snippet whenever I add a UITableView in any of my view controllers.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if(cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle 
                                      reuseIdentifier:cellIdentifier];
            // Do something here......................
    }
    // Do something here too .........................
    return cell;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return ;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return ;
}

its quite handy if you are not using a UITableViewController to show table contents.

Answer 2

Dispatch block on the current queue after given number of seconds:

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, <#seconds#>*1e9),
    dispatch_get_current_queue(), <#block#>);