Swift4 imagepicker giving me "Class 'viewcontroller' has no initializers" - ios

Question

I just started to learn swift and have almost no background on developing.
I'm making an app which involves image picker.
While making such function, I get this message saying Class 'viewcontroller' has no initializers.
How do I initialize viewcontroller?
I've searched other posts, but due to my lack of knowledge on developing languages, I'm having hard time understanding the solution.
Thanks in advance.
import UIKit
import MobileCoreServices
class viewcontroller: UIViewController, UINavigationControllerDelegate,
UIImagePickerControllerDelegate {
#IBOutlet var imgView: UIImageView!
let imagepicker: UIImagePickerController! = UIImagePickerController()
var captureimage: UIImage
var videoURL: URL!
var flagImageSave = false
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func btnCaptureImageFromCamera(_sender:UIButton) {
if (UIImagePickerController.isSourceTypeAvailable(.camera)) {
flagImageSave = true
imagepicker.delegate = self
imagepicker.sourceType = .camera
imagepicker.mediaTypes = [kUTTypeImage as String]
imagepicker.allowsEditing = false
present (imagepicker, animated: true, completion: nil)
}
}
#IBAction func btnLoadImageFromLibrary(_sender: UIButton) {
flagImageSave = false
imagepicker.delegate = self
imagepicker.sourceType = .photoLibrary
imagepicker.mediaTypes = [kUTTypeImage as String]
imagepicker.allowsEditing = true
present (imagepicker, animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
let mediaType = info[UIImagePickerControllerMediaType] as! NSString
if mediaType.isEqual(to: kUTTypeImage as NSString as String) {
captureimage = info[UIImagePickerControllerOriginalImage] as! UIImage
if flagImageSave {
UIImageWriteToSavedPhotosAlbum(captureimage, self, nil, nil)
}
imgView.image = captureimage
}
}
}
func btnCaptureImageFromCamera(_ sender: UIButton) {
}
func btnLoadImageFromLibrary(_ sender: UIButton) {
}

Answer 1

Firstly, style should be ViewController (not viewcontroller), and ideally more descriptive like TheImageViewController but anyway...
At a guess the issue is:
var captureimage: UIImage
Try:
var captureimage: UIImage?
As you have a non-primitive type, that is not ? or ! (read swift docs)

Answer 2

This happens because you declared captureimage property as non optional but haven't provided any instances of this property. To fix this you can either provide default value
var captureimage: UIImage = UIImage()
or make captureimage property optional
var captureimage: UIImage?