Load some private var on switch condition - ios

Question

I'm making a simple iOS game, and I have some problems.
Indeed, I created my different classes for my elements : planet, bullet, background, and asteroids.
However when I try to initialize them on switch condition (from the GameScene), I have the error message "expected declaration".
The variable "lvlSelected", is global and represents the level asked by the player (from an other scene).
Here's my switch code :
switch lvlSelected {
case 1 :
private var planet = Planet(imageName: "Planet1")
private var bullet = Bullet(imageName: "Bullet1")
private var background = Background(imageName: "Background1")
private var asteroide = Asteroides(img: "Asteroid1")
case 2 :
private var planet = Planet(imageName: "Planet2")
private var bullet = Bullet(imageName: "Bullet2")
private var background = Background(imageName: "Background2")
private var asteroide = Asteroides(img: "Asteroid2")
default :
private var planet = Planet(imageName: "Planet")
private var bullet = Bullet (imageName: "Bullet")
private var background = Background(imageName : "Background")
private var asteroide = Asteroides(img."Asteroid")
}
Thanks for your help
Here's my Planet's class :
class Planet:SKSpriteNode {
init(imageName: String){
let texture = SKTexture(imageNamed : imageName)
super.init(texture: texture, color: .clear, size: texture.size())
self.physicsBody = SKPhysicsBody(circleOfRadius: self.size.width/2, center: self.anchorPoint)
self.physicsBody!.affectedByGravity = false
self.physicsBody!.categoryBitMask = GameScene.physicsCategories.planet
self.physicsBody!.collisionBitMask = GameScene.physicsCategories.none
self.physicsBody!.contactTestBitMask = GameScene.physicsCategories.asteroid
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func addPlanet(parent: GameScene) {
self.setScale(0.55)
self.position = CGPoint(x: parent.size.width / 2, y: -self.size.height)
self.zPosition = 2
self.anchorPoint = CGPoint(x: 0.5, y: 0.5)
parent.addChild(self)
}

Answer 1

This should be the way you want.
private var planet = Planet(imageName: "Planet")
private var bullet = Bullet (imageName: "Bullet")
private var background = Background(imageName : "Background")
private var asteroide = Asteroides(img."Asteroid")
switch lvlSelected {
case 1 :
planet = Planet(imageName: "Planet1")
bullet = Bullet(imageName: "Bullet1")
background = Background(imageName: "Background1")
asteroide = Asteroides(img: "Asteroid1")
break
case 2 :
planet = Planet(imageName: "Planet2")
bullet = Bullet(imageName: "Bullet2")
background = Background(imageName: "Background2")
asteroide = Asteroides(img: "Asteroid2")
break
default :
break
}
If you declare a var inside a switch case will be available inside that case only.

Answer 2

There is no need for a switch in your case, you can use string interpolation:
class GameScene : SKScene
{
private let planet : Planet
private let bullet : Bullet
private let background : Background
private let asteroide : Asteroides
convenience init(lvlSelected : Int){
let level = 1 ... 2 ~= lvlSelected ? "\(lvlSelected)" : ""
planet = Planet(imageName: "Planet\(level)")
bullet = Bullet (imageName: "Bullet\(level)")
background = Background(imageName: "Background\(level)")
asteroid = Asteroides(img: "Asteroid\(level)")
self.init() //whatever init you use here
}
}
~= is the pattern match operator, and #a ... #b means range of numbers between a and b including a and b, so you are asking if a number is in a certain range
(condition) ? (statement 1) : (statement 2) is the ternary operator which is if condition true then statement 1 else statement 2
"\(var)" is string interpolation that tells the string to inject the value of var into the string