How to trigger NSTimer right away?

I need to call a method when my app starts and then call the same method every 5 seconds.

My code is pretty simple:

// Call the method right away
[self updatestuff:nil]

// Set up a timer  so the method is called every 5 seconds
timer = [NSTimer scheduledTimerWithTimeInterval: 5
                                          target: self
                                        selector: @selector(updatestuff:)      
                                        userInfo: nil
                                         repeats: YES];

Is there an option for the timer so it's trigger right away and then every 5 seconds ?

NSTimer's -fire, [timer fire]; is what you're looking for.

That will fire/immediately call the timer dismissing the time delay.

You can't schedule the timer and fire the event immediately all in the same line of code. So you have to do it in 2 lines of code.

First, schedule the timer, then immediately call 'fire' on your timer:

timer = [NSTimer scheduledTimerWithTimeInterval: 5
                                      target: self
                                    selector: @selector(updatestuff:)      
                                    userInfo: nil
                                     repeats: YES];
[timer fire];

When fire is called, the time interval that your timer waits to fire will reset because it just ran, and then will continue to run thereafter at the designated interval--in this case, every 5 seconds.

In Swift:

timer = Timer.scheduledTimer(timeInterval: interval, target: self, selector: #selector(foo), userInfo: nil, repeats: true)
timer.fire()

You can initialise the timer and fire it in the same line:

[(checkStatusTimer = [NSTimer scheduledTimerWithTimeInterval:60.0 target:self selector:@selector(checkStatusTimerTick:) userInfo:nil repeats:YES]) fire];

In swift this can be achieved in one line like:

Timer.scheduledTimer(withTimeInterval: intervalInSec, repeats: true) { 

}