Camera move with my character - swift

Question

I have this little project I'm working on, and I'm a complete beginner. I need some help how I could implement a working camera that would follow the "char" around. Thanks in advance.
If you could point me in the right direction, as to where I add the code. That would be terrific, since I looked over some tutorials, and didnt really know as to where to put some of the code.
class GameScene: SKScene {
var char = SKSpriteNode()
var bg = SKSpriteNode()
var platform = SKSpriteNode()
override func didMoveToView(view: SKView) {
/* Setup your scene here */
var bgTexture = SKTexture(imageNamed: "img/bg.png")
bg = SKSpriteNode(texture: bgTexture)
bg.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
bg.size.height = self.frame.height
self.addChild(bg)
var charTexture = SKTexture(imageNamed: "img/char.png")
char = SKSpriteNode(texture: charTexture)
char.position = CGPoint(x:CGRectGetMidX(self.frame), y: 900)
char.physicsBody = SKPhysicsBody(circleOfRadius: char.size.height / 2)
char.physicsBody!.dynamic = true
self.addChild(char)
var platformTexture = SKTexture(imageNamed: "img/platform.png")
platform = SKSpriteNode(texture: platformTexture)
platform.position = CGPoint(x:CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
platform.physicsBody = SKPhysicsBody(rectangleOfSize: platform.size)
platform.physicsBody!.dynamic = false
self.addChild(platform)
var wall = SKNode()
wall.position = CGPointMake(0,0)
wall.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(1, self.frame.size.height))
wall.physicsBody!.dynamic = false
self.addChild(wall)
var ground = SKNode()
ground.position = CGPointMake(0, 0)
ground.physicsBody = SKPhysicsBody(rectangleOfSize: CGSizeMake(self.frame.size.width, 1))
ground.physicsBody!.dynamic = false
self.addChild(ground)
}
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
/* Called when a touch begins */
char.physicsBody?.velocity = CGVectorMake(0,0)
char.physicsBody?.applyImpulse(CGVectorMake(3, 0))
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}