Syntax for multiple default parameter call

Question

I am trying to make a "Label Factory" that will help me to produce labels for a project.

I have a function

getLabel(of type: LabelTypeEnum,
                         _ labelTitle: String? = nil,
                         _ textColor: UIColor? = nil,
                         _ textAlignment: NSTextAlignment? = nil) -> Label 

I then want to call it with any number of parameters, for example:

getLabel(of: .myLabel, .center)

which results in the error: " Type 'String?' has no member 'center' "

How do I tell the compiler that .center is not the labelTitle property?

I tried to specify the content by adding "alignment: .center" but it forces me to delete it.

If it's of any help I will ad the context of the code below.

static func getLabel(of type: LabelType,
                          _ labelTitle: String? = nil,
                          _ textColor: UIColor? = nil,
                          _ textAlignment: NSTextAlignment? = nil) -> Label {
        switch type {

        case .regular:
            return RegularLabel(labelTitle, textColor, textAlignment)

        case .title:
            return TitleLabel(labelTitle, textColor, textAlignment)
        case .description:
            return DescriptionLabel(labelTitle, textColor, textAlignment)
        case .header:
            return HeaderLabel(labelTitle, textColor, textAlignment)

        case .subHeader:
            return SubHeaderLabel(labelTitle, textColor, textAlignment)

        case .body:
            return BodyLabel(labelTitle, textColor, textAlignment)

        case .fatBody:
            return FatBodyLabel(labelTitle, textColor, textAlignment)

        case .smallGray:
            return SmallGrayLabel(labelTitle, textColor, textAlignment)
        }
    }

Label init

convenience init(_ title: String? = nil, _ color: UIColor? = nil, _ alignment: NSTextAlignment? = nil) {
        self.init(frame: .zero)
        self.text = title ?? self.text
        self.textColor = color ?? self.textColor
        self.textAlignment = alignment ?? self.textAlignment
    }

One of many calls

private lazy var titleLabel: UILabel = {
        let label = LabelFactory.getLabel(of: .header, .center)
        self.addSubview(label)
        return label
    }()

Answer 1

It's the curse of omitting the parameter labels because of convenience, this is supposed to work:

getLabel(of type: LabelTypeEnum,
      labelTitle: String? = nil,
       textColor: UIColor? = nil,
   textAlignment: NSTextAlignment? = nil) -> Label

getLabel(of: .myLabel, textAlignment: .center)