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

Posted by christian elam
christian elam
6,443 Points

I have no clue how to figure this out!!??

I am really confused and have no idea how to complete this challenge could you help me please!!?????

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
christian elam
christian elam
6,443 Points

Here are the directions below

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.

christian elam
christian elam
6,443 Points

And by the way does anyone know how to skip a ending challenge such as this because other challenges that are in the middle of your courses and classes you can just click the next one but since this is on the end you can't skip it or atleast I dont know how

1 Answer

David Papandrew
David Papandrew
8,386 Points
David Papandrew
David Papandrew
8,386 Points

Hi Christian,

Here's the code:

class Robot: Machine {
    override func move(direction: String) {
        switch direction {
            case "Up": self.location.y += 1
            case "Down": self.location.y -= 1
            case "Right": self.location.x += 1
            case "Left": self.location.x -= 1
        default: print("Do nothing") // Or you could put a break clause per the instructions
        }
    }
}

Some explanations:

1) The first line defines a subclass of Machine

2) The 2nd line creates a class method "move" that overrides the move method of the Machine parent class (remember that due to inheritance, we need to "override" the move function if we want the subclass to have its own behavior).

3) We use a switch statement to check for all the move inputs (which we receive as a parameter "direction")

4) Up/Down directions will change our y coordinate. As you recall, the Machine class defines these.

5) Right/Left changes the x coordinate for the object

Hope that helps.

christian elam
christian elam
6,443 Points

THANK YOU SO MUCH!!!! I didn't realize I had to make separate classes for that. THANK YOU FOR HELPING ME I REALLY APPRECIATE IT!!!!!!!!!