Issue retrieving members from objects in array, value of type 'Shape' has no member 'name'

Question

New to Swift, if anyone could point me in the right direction it would be greatly appreciated. I'm attempting to pull member values from an object array and output as strings as follows. This is inside a playground, if that has any effect on the situation.

// Main Class for array building later
class Shape {

}

//Implement the protocol on a Triangle, Square, and Rectangle.
class Triangle:Shape, Polygon {
    var a: Float
    var b: Float
    var c: Float
    var name: String = "Triangle"
    var sides: Int = 3

    init(a: Float, b:Float, c: Float) {
        self.a = a
        self.b = b
        self.c = c
    }

    func perimiter() -> Float {
        return a+b+c
    }

    func area() -> Float {
        let sp = (a+b+c)/2
        let area = sqrtf(sp*(sp-a)*(sp-b)*(sp-c))
        return area
    }
}

class Square:Shape, Polygon {
    var a: Float
    var name: String = "Square"
    var sides: Int = 4
    init(a: Float) {
        self.a = a
    }

    func perimiter() -> Float {
        return a*4
    }

    func area() -> Float {
        return a*2
    }
}

class Rectangle:Shape, Polygon {
    var a: Float
    var b: Float
    var name: String = "Rectangle"
    var sides: Int = 4
    init(a: Float, b: Float) {
        self.a = a
        self.b = b
    }

    func perimiter() -> Float {
        return 2*(a*b)
    }
    func area() -> Float {
        return a*b
    }
}

protocol Polygon {
    var name: String { get }
    var sides: Int { get }
    func perimiter() -> Float
    func area() -> Float
}

//MARK: Create Instances of, return array of
func makeShapes() -> [Shape]{
    let s1 = Triangle(a:3,b:4,c:5)
    //print(s1.name) works fine here
    //print(s1.perimiter().description)
    //print(s1.area().description)
    let s2 = Triangle(a:6,b:8,c:10)
    let s3 = Square(a: 15)
    let s4 = Square(a: 25)
    let s5 = Rectangle(a:20,b:13)
    let s6 = Rectangle(a:17,b:50)

    return [s1,s2,s3,s4,s5,s6]
}


func draw (shapes: [Shape]) {  
    shapes.forEach { shape in
        print(shape.name)
    }
}

var shapes = makeShapes()
draw(shapes: shapes)

I can see that it's passing the objects around on the right side of the playground, and I can see all of the member values even outside makeShapes(), I just can't get to them to print(), it gives me a "Value of type has no member error. Again, any help or nudges in the right direction as to what I'm guessing is something obvious I'm missing would be greatly appreciated, thanks ahead of time!

Answer 1

The Shape class doesn't have a member called name just as the error describes.

In any case, Shape shouldn't be a class. Instead it should be a protocol.

protocol Shape {
    var name: String { get }
}

Or you should be drawing Polygons instead of shapes.

func draw (shapes: [Polygon]) {
    shapes.forEach { shape in
        print(shape.name)
    }
}

var shapes = makeShapes()
draw(shapes: shapes as! [Polygon])