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

Code Challenge

I've been stuck of this and I need help!

In the editor you've been provided with two classes - Point to represent a coordinate point and Machine. The machine has a move method that doesn't do anything because most machines are motionless.

Your task is to subclass Machine and create a new class named Robot. In the Robot class, override the move method and provide the following implementation. If you enter the string "Up" the y coordinate of the Robot's location increases by 1. "Down" decreases it by 1. If you enter "Left", the x coordinate of the location property decreases by 1 while "Right" increases it by 1.

Note: If you use a switch statement you can use the break statement in the default clause to exit the current iteration.

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! Im a machine!")
    }
}

// Enter your code below

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! Im a machine!")
}

}

class Robot: Machine {

override func move(direction: String)  {

    switch direction {

    case "Up" : location.y += 1
    case "Down" : location.y -= 1
    case "Left" : location.x -= 1
    case "Right" : location.x += 1
    break
    default: "nothing"
    }

    print(location.y)            //this line is to check change

}

}

let sample = Robot() // x and y already initialized in Machine class, no need override in Robot class

sample.move("Down") // while writing in playground the code is sample.move(direction: "Down")

2 Answers

Moritz Lang
Moritz Lang
25,909 Points

Hey Jared, can you please tell us on which part of the challenge you stuck? I could provide you with the solution righth now, but I think that it wouldn't help you in learning how to code by yourself.

Overriding the subclass with the move method

``` 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! Im a machine!")
}

}

class Robot: Machine {

override func move(direction: String) {

    switch direction {

    case "Up" : location.y += 1
    case "Down" : location.y -= 1
    case "Left" : location.x -= 1
    case "Right" : location.x += 1
    break
    default: "nothing"
    }
print(location.y)   //this line is to check change

} }

let sample = Robot() // x and y already initialized in Machine class, no need override in Robot class sample.move("Down") // while writing in playground the code is sample.move(direction: "Down")