Override func update(_ currentTime: TimeInterval) is not working!

📚 Official Books 2D iOS & tvOS Games by Tutorials
1

I just started working on SpriteKit, today.

I tried to paste the above function into my GameScene file and I get an error.
The error states that “override can only be specified on class members”
“Fix it - Delete override”

So, what am I doing wrong?

Here’s my code:

import SpriteKit
import GameplayKit

class GameScene: SKScene
{
override func didMove(to view: SKView)
{
backgroundColor = SKColor.black
let background = SKSpriteNode(imageNamed: “background1”)
// background.position = CGPoint(x: size.width/2, y: size.height/2)

// background.anchorPoint = CGPoint.zero
// background.position = CGPoint.zero

background.anchorPoint = CGPoint(x: 0.5, y: 0.5) // default
background.position = CGPoint(x: size.width/2, y: size.height/2)

// background.zRotation = CGFloat(M_PI) / 8
addChild(background)
let mySize = background.size
print(“Size: (mySize)”)
background.zPosition = -1

let zombie = SKSpriteNode(imageNamed:"zombie1")
zombie.position = CGPoint(x: 400, y: 400)

// zombie.setScale(2)

addChild(zombie)

override func update(_ currentTime: TimeInterval)
{
  zombie.position = CGPoint(x: zombie.position.x + 8, y: zombie.position.y)
}

}
}

Thanks,

Gary

2

Never mind!
I figured out my own error. I had defined the constant variable

"let zombie = SKSpriteNode(imageNamed:“zombie1”)
locally in the previous function.

I’ve now made it a global constant and all is working great again.

Gary

1 Like
3

Hey elearner,

I am getting the same errors as you were. Can you tell me how you fixed it ?

I dont know how to define ‘zombie1’ as a global constant.

also the book suggests adding the below code inside GameScene.Swift, which i took to mean anywhere in the file (and not inside the DidMove(to:) as you have done above.

override func update(_ currentTime: TimeInterval) {
zombie.position = CGPoint (x: zombie.position.x + 8,
y: zombie.position.y)
}

Thanks in advance.

4

Hello muzafar,

Here’s my code that shows where to declare the “zombie1” constant.
It’s in bold so you can see where it’s declared.

import SpriteKit
import GameplayKit

class GameScene: SKScene
{
var lastTouchLocation: CGPoint?
let playableRect: CGRect
var lastUpdateTime: TimeInterval = 0
var dt: TimeInterval = 0
let zombieRotateRadiansPerSec:CGFloat = 4.0 * π
let zombie = SKSpriteNode(imageNamed: “zombie1”) //declared above your first function
let zombieMovePointsPerSec: CGFloat = 480.0
var velocity = CGPoint.zero

override func didMove(to view: SKView)
{
debugDrawPlayableArea()
let background = SKSpriteNode(imageNamed: “background1”)
background.position = CGPoint(x: size.width/2, y: size.height/2)
background.anchorPoint = CGPoint(x: 0.5, y: 0.5) //default
background.zPosition = -1
addChild(background)
zombie.position = CGPoint(x:400,y:400)
// zombie.anchorPoint = CGPoint(x: 0.0, y: 0.0) //default
zombie.zPosition = 100
addChild(zombie) //this is where you load the zombie image

}

Let me know if that helped.

Gary

5

@elearner

That solved it. thanks !