How to set Random height of image

var cellHeight : Int = Int()

switch(Int(arc4random_uniform(4)))

{

case 1 :

    cellHeight = 200

    break

case 2 :

    cellHeight = 230

    break

case 3 :

    cellHeight = 260

    break

case 4 :

    cellHeight = 290

    break

    

default:

    cellHeight = 320

    break

}

dict.setValue(cellHeight, forKey: "cellHeight")

self.arrListing.add(dict)

 func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize

    {

        if collectionView == listCollectionView

        {

            let padding: CGFloat =  30

            let collectionViewSize = collectionView.frame.size.width - padding

            

            return CGSize(width: collectionViewSize/2, height: CGFloat(((self.arrListing.object(at: indexPath.row) as! NSDictionary).value(forKey: "cellHeight") as? Int)!))

        }

        else

        {

            return CGSize(width: 50, height: 50)

            

        }

    }