[Swift4] Image from URL

1. do, catch

      let url = URL(string: user.imageURL)
      do {
            let data = try Data(contentsOf: url!)
            let image = UIImage(data: data)

       }catch let err {
            print("Error : \(err.localizedDescription)")
       }

2. URLSession

 if let image = imageURL { 
   let url = URL(string: image) 
   URLSession.shared.dataTask(with: url!, completionHandler: { (data, response, error) in 

      if error != nil { 
         print(error!) 
         return 
      } 

      DispatchQueue.main.async { 
         imageView.image = UIImage(data: data!) 
      } 
   }).resume() 
}