Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

iOS Build a Simple iPhone App with Swift 2.0 Getting Started with iOS Development Swift Recap Part 2

JUNSEI TEI
JUNSEI TEI
2,055 Points

HELP

Can anyone help me explain a bit, what should be the parameter in override init(), and what should be the parameter in super.init(), both for this question and in general. I get confused with these concepts. And as well, why I cannot use location.x and location.y in the subclass. Does it has anything to do with my wrong override initialization?

classes.swift
class Point {
    var x: Int
    var y: Int

    init(x: Int, y: Int){
        self.x = x
        self.y = y
    }
}


class Machine {
    var location: Point

    init() {
        self.location = Point(x: 0, y: 0)
    }

    func move(direction: String) {
        print("Do nothing! I'm a machine!")
    }
}

// Enter your code below
class Robot: Machine{
    override init(){
        super.init(location: Point1(x: 0, y: 0))
    }
}
override func move(direction: String) {
    switch direction{
    case "Up": location.y ++
    case "Down": location.y --
    case "Left": location.x --
    case "Right": location.x ++
    default: break
    }
}

1 Answer

Hi there,

I don't think you need to override the init method. Also, your func needs to be inside the class. Then, if you remove the spaces between location.x etc. and the increment and decrement operators; it'll work fine:

class Robot : Machine {
  override func move(direction: String) {
    switch direction{
      case "Up": location.y++
      case "Down": location.y--
      case "Left": location.x--
      case "Right": location.x++
      default: break
    }
  }
}

Steve.