Application getting crashed while setting image in a variable - ios

Question

I am trying to store an image in a variable, but my application is getting crashed on the below given line:
let theImage = UIImage(named: self.arrImages[indexPath.row])!
Here, arrImages is an array which contains images.
Crash which I am getting is
Fatal error: unexpectedly found nil while unwrapping an Optional values
Edit 1
As required by #Duncan C & #Valentin
Declaration:
var arrImages = [String]()
Using it in delegate of UICollectionView
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
if collectionView == self.collectionView
{
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! ImageCell
cell.imageView.image = nil
var theImage = UIImage()
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), {
if let image = UIImage(named: self.arrImages[indexPath.row]) {
// Do whatever you like with the image here
theImage = UIImage(named: self.arrImages[indexPath.row])!
}
dispatch_async(dispatch_get_main_queue(), {
cell.imageView.image = theImage
cell.imageView.contentMode = .ScaleAspectFit
});
})
return cell
}

Answer 1

You are not providing enough information, and some of the things you did say do not make sense.
Post the declaration of your arrImages, as well as the code that installs values into the array.
You say that your array contains images, but your code is expecting the array to contain image filenames (strings).
Next, you need to break your code into steps and debug it:
let index = indexPath.row
let imageName = self.arrImages[index];
println("At index \(index), imageName = \"\(imageName)\"")
let image = UIImage(named: imageName)
println("Image = \(image)")

Answer 2

Try binding it with
if let image = UIImage(named: ...) {
// Do whatever you like with the image here
}