title: Swift: Repeat action after a random period of time
body: <p>Previously, with Objective-C I could use performSelector: in order to repeat an action after a random period of time which could vary between 1-3 seconds. But since I'm not able to use performSelector: in Swift, I've tried using "NSTimer.scheduledTimerWithTimeInterval". And it works in order to repeat the action. But there is a problem. On set the time variable to call a function that will generate a random number. But it seems that NSTimer uses the same number every time it repeats the action. </p>
  
  <p>What that means is that the action is not performed randomly, but instead, after a set period of time that is generated randomly at the beginning of the game and it is used during all the game. </p>
  
  <p>The question is: Is there any way to set the NSTimer to create a random number every time it executes the action? Or should I use a different method? Thanks!</p>