Swipe UIImageView array loop - arrays

Question

i am new here and I am also a beginner in Swift!
I am trying to create an UIImageView to swipe left and right, when i get to the last image the app crash, the same crash happen if i am in the first image and try to swipe to the right!
What i wanna do is when my array of Images reaches the last image send me back to the First image in a loop, can anyone help me please?
Thank you in advance!!!
Here is my code;
func swiped(gesture: UIGestureRecognizer) {
CATransaction.begin()
CATransaction.setAnimationDuration(animationDuration)
CATransaction.setCompletionBlock {
let delay = dispatch_time(DISPATCH_TIME_NOW, Int64(self.switchingInterval * NSTimeInterval(NSEC_PER_SEC)))
dispatch_after(delay, dispatch_get_main_queue()) {
}
}
let transition = CATransition()
transition.type = kCATransitionFade
chracters.layer.addAnimation(transition, forKey: kCATransition)
CATransaction.commit()
if let swipeGesture = gesture as? UISwipeGestureRecognizer {
switch swipeGesture.direction {
case UISwipeGestureRecognizerDirection.Right :
print("User swiped right")
// decrease index
imageIndex -= 1
// check if index is in range
if swipePosition > imageList.count-1{
// Do Nothing
} else {
swipePosition += 1
}
chracters.image = UIImage(named: imageList[imageIndex])
case UISwipeGestureRecognizerDirection.Left:
print("User swiped Left")
// increase index first
imageIndex += 1
// check if index is in range
if swipePosition == 0 {
//Do Nothing
} else {
swipePosition -= 1
}
chracters.image = UIImage(named: imageList[imageIndex])
default:
break;
//stops the code
}
}
}

Answer 1

First your condition seems to be amiguous, you can use swipePosition itself instead of imageIndex. Secondly your chracters.image should inside the if/else block. Below is the updated snippet. If you want to use imageIndex you can change it accordingly. Also added the code to switch from last image to first image and first image to last.
if swipePosition > imageList.count-1{
swipePosition = 0
chracters.image = UIImage(named:imageList[swipePosition]
} else {
chracters.image = UIImage(named:imageList[swipePosition]
swipePosition += 1
}
case UISwipeGestureRecognizerDirection.Left:
print("User swiped Left")
// check if index is in range
if swipePosition == 0 {
swipePosition = imageList.count-1
chracters.image = UIImage(named:imageList[swipePosition]
} else {
chracters.image = UIImage(named:imageList[swipePosition]
swipePosition -= 1
}