仅从 Swift 的 UserDefaults 中的 int 数组中删除特定的 int 值

Question

I made a like button on a book page. When I press a like button, the image of the button changes. The page number is stored in an Int Array in UserDefaults.

But when I cancelled the like, page numbers stored in Int Array UserDefaults should be deleted.

How can I delete a specific number inside an Int Array in UserDefaults?

@objc func likeBtnClicked(_ sender: UIButton) {
        DispatchQueue.main.async {
            if sender.isSelected == false {
                sender.setBackgroundImage(UIImage(named: "fill-heart"), for: .normal)

                UserDefaults.standard.set(self.bookPage, forKey: "\(self.bookNo ?? "")")

self.likePageArr.append(UserDefaults.standard.object(forKey: "\(self.bookNo ?? "")") as! Int)

                var likePageArray = UserDefaults.standard.array(forKey: "\(self.bookNo ?? "")Arr") as? [Int] ?? [Int]()

                    UserDefaults.standard.set(self.likePageArr, forKey: "\(self.bookNo ?? "")Arr")

                sender.isSelected = true

            } else if sender.isSelected == true {
                sender.setBackgroundImage(UIImage(named: "none-heart"), for: .normal)
                UserDefaults.standard.removeObject(forKey: "\(self.bookNo ?? "")")

                var likePageArray = UserDefaults.standard.array(forKey: "\(self.bookNo ?? "")Arr") as? [Int] ?? [Int]()

                likePageArray.remove(at: likePageArray.index(of: self.bookPage) ?? 0)

//i need delete self.bookPage in likePageArray

                sender.isSelected = false
            }
        }

Answer 1

You have already removed the value from the array here:

likePageArray.remove(at: likePageArray.index(of: self.bookPage) ?? 0)

Now, you just need to re-write the array back to UserDefaults (like you did before):

UserDefaults.standard.set(self.likePageArr, forKey: "\(self.bookNo ?? "")Arr")

Answer 2

You cannot update specific value inside array in UserDefaults. Firstly, you need to get specific object from UserDefaults and store in one variable, make required changes in that variable and save that variable in UserDefaults.