Swift NSUserDefaults unexpectedly found nil while unwrapping an Optional value - ios

Question

//Help Please This Code won't work, getting this as feedback from Xcode.
fatal error: unexpectedly found nil while unwrapping an Optional value
var savedScore = NSUserDefaults.standardUserDefaults().objectForKey("HighestScore") as! Int
import SpriteKit
class GameScene: SKScene {
var highestScore:Int = 2
var score = Int()
override func didMoveToView(view: SKView) {
/* Setup your scene here */
//To save highest score
//To get the saved score
var savedScore = NSUserDefaults.standardUserDefaults().objectForKey("HighestScore") as! Int
print(savedScore)
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
/* Called when a touch begins */
score += 1
print("Score - \(score)")
if score > highestScore
{
highestScore = score
NSUserDefaults.standardUserDefaults().setObject(highestScore, forKey:"HighestScore")
NSUserDefaults.standardUserDefaults().synchronize()
print("Beat")
}
else {
print("Not Beat")
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
}

Answer 1

You are calling the userDefaults function before it ever saves. You need to check if it exists. First you can make it easier on yourself and just save it as an integer. Then you need to check to see if there is a value.
NSUserDefaults.standardUserDefaults().setInteger(highestScore, forKey: "HighestScore")
//IntegerForKey will never return nil. This will return 0 if there is no value.
let savedScore = NSUserDefaults.standardUserDefaults().integerForKey("HighestScore")
print(savedScore)

Answer 2

NSUserDefaults.standardUserDefaults is a Dictionary Object. If you try to read a value that has not set value before, you will get a nil. You could check if the value for key exist
let savedScore = NSUserDefaults.standardUserDefaults.integerForKey("HighestScore") ?? 0
Then if value for HighestScore exist, you will get the correct value, if not, you will set 0 as default value for savedScore.

Answer 3

Thank you guys I got it yesterday but didn't find time to get on here and post it but here is the code that works. Thank You Guys again that helped!
class GameScene: SKScene {
var score = Int()
var highScore = Int()
override func didMoveToView(view: SKView) {
/* Setup your scene here */
//IntegerForKey will never return nil. This will return 0 if there is no value.
highScore = NSUserDefaults.standardUserDefaults().integerForKey("HighestScore")
print("highScore - \(highScore)")
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
/* Called when a touch begins */
score += 1
print("Score - \(score)")
if score > highScore
{
highScore = score
NSUserDefaults.standardUserDefaults().setObject(highScore, forKey:"HighestScore")
NSUserDefaults.standardUserDefaults().synchronize()
print("Beat")
}
else {
print("Not Beat")
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
}