Increment score in Sprite Kit to show in HUD - ios

Question

I know I'm close in getting the getting the score to increment in my game.
When I explicitly change the code to add a integer (5 for example) instead of "%d", the score shows in the HUD when a coin is touched :
func didBeginContact(contact: SKPhysicsContact) {
lblScore.text = String(format: "%d", GameState.sharedInstance.score)
}
to:
func didBeginContact(contact: SKPhysicsContact) {
lblScore.text = String(format: "5", GameState.sharedInstance.score)
}
However if I leave the "%d", then nothing happens. I'm not sure how to increment the score in the HUD or where to make changes.
Here's the rest of the code.
GameScene.swift:
struct PhysicsCategory {
static let None: UInt32 = 0
static let Player: UInt32 = 0b1
static let CoinNormal: UInt32 = 0b1000
static let CoinSpecial: UInt32 = 0b10000
}
class GameScene: SKScene, SKPhysicsContactDelegate {
// HUD
var hudNode: SKNode!
var lblScore: SKLabelNode!
var lblCoins: SKLabelNode!
override func didMoveToView(view: SKView) {
// HUD
hudNode = SKNode()
hudNode.zPosition = 1000
cameraNode.addChild(hudNode)
// Coins
// 1
let coin = SKSpriteNode(imageNamed: "powerup05_1")
coin.position = convertPoint(CGPoint(x: 300, y: self.size.height-100), toNode: cameraNode)
coin.zPosition = 1000
hudNode.addChild(coin)
// 2
lblCoins = SKLabelNode(fontNamed: "ChalkboardSE-Bold")
lblCoins.fontSize = 70
lblCoins.fontColor = SKColor.whiteColor()
lblCoins.position = convertPoint(CGPoint(x: 375, y: self.size.height-100), toNode: cameraNode)
lblCoins.horizontalAlignmentMode = SKLabelHorizontalAlignmentMode.Left
lblCoins.zPosition = 1000
// 3
lblCoins.text = String(format: "X %d", GameState.sharedInstance.coins)
hudNode.addChild(lblCoins)
// Score
// 4
lblScore = SKLabelNode(fontNamed: "ChalkboardSE-Bold")
lblScore.fontSize = 70
lblScore.fontColor = SKColor.whiteColor()
lblScore.position = convertPoint(CGPoint(x: self.size.width-325, y: self.size.height-100), toNode: cameraNode)
lblScore.horizontalAlignmentMode = SKLabelHorizontalAlignmentMode.Right
lblScore.zPosition = 1000
// 5
lblScore.text = "0"
hudNode.addChild(lblScore)
}
}
func didBeginContact(contact: SKPhysicsContact) {
lblScore.text = String(format: "%d", GameState.sharedInstance.score)
}
GameState.swift:
class GameState {
var score: Int
var highScore: Int
var coins: Int
init() {
// Init
score = 0
highScore = 0
coins = 0
// Load game state
let defaults = NSUserDefaults.standardUserDefaults()
highScore = defaults.integerForKey("highScore")
coins = defaults.integerForKey("coins")
}
func saveState() {
// Update highScore if the current score is greater
highScore = max(score, highScore)
score = max(score, highScore)
// Store in user defaults
let defaults = NSUserDefaults.standardUserDefaults()
defaults.setInteger(highScore, forKey: "highScore")
defaults.setInteger(coins, forKey: "coins")
NSUserDefaults.standardUserDefaults().synchronize()
}
class var sharedInstance: GameState {
struct Singleton {
static let instance = GameState()
}
return Singleton.instance
}
}

Answer 1

As I can see you are using GameState.sharedInstance.score to store a score. But you never update it. You have to increment the score each time when player scores. This part:
lblScore.text = String(format: "%d", GameState.sharedInstance.score)
only reads from a score variable.
Also this part doesn't make sense:
highScore = max(score, highScore)
score = max(score, highScore) //remove this
score variable is not the same as highscore variable.

Answer 2

I was able to increment the score by this line:
GameState.sharedInstance.score += 1
Or replace 1 with another number by how many points you want to increment.