Swift 3 unexpectedly found nil while unwrapping an Optional value [duplicate] - swift

Question

This question already has answers here:
What does "Fatal error: Unexpectedly found nil while unwrapping an Optional value" mean?
(16 answers)
Closed 5 years ago.
Whenever I tried to fetch the data from firebase this happen
This is my code
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: self.postCell, for: indexPath) as! PostCell
cell.postedImage.downloadImageUrl(from: setPost[indexPath.section].userPostImage)
cell.postItemPriceLabel.text = setPost[indexPath.section].userPriceTag
cell.selectionStyle = .none
return cell
}
override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let cell = tableView.dequeueReusableCell(withIdentifier: self.headerCell) as! HeaderCell
cell.profileImage.downloadImageUrl(from: setPost[section].userphoto)
cell.fullname.text = setPost[section].fullname
cell.backgroundColor = UIColor.white
return cell
}
extension UIImageView {
func downloadImageUrl(from imgUrl: String!){
let url = URLRequest(url: URL(string: imgUrl)!)
let session = URLSession.shared
session.dataTask(with: url){
(data, response, err) in
if err != nil {
print(err!)
return
}
DispatchQueue.main.async {
self.image = UIImage(data: data!)
}
}.resume()
Please someone should help me out
Thanks

Answer 1

You need to make sure that the string used to create a URL object (imgUrl) can be used to create a URL object, if it doesn't, you shouldn't continue.
This can be made by using an if let statement:
if let url = URL(string: imgUrl) {
let urlRequest = URLRequest(url: url)
let session = URLSession.shared
session.dataTask(with: urlRequest){
(data, response, err) in
if err != nil {
print(err!)
return
}
DispatchQueue.main.async {
self.image = UIImage(data: data!)
}
}.resume()
}