How can I extend this UIColor hex function to include alpha?

Question

How can I include alpha inside this UIColor extension?

extension UIColor {

    convenience init(hex:Int) {
        self.init(red:(hex >> 16) & 0xff, green:(hex >> 8) & 0xff, blue:hex & 0xff)
    }
}

Answer 1

First of all, UIColor does not have any initializers that would take integers. I am assuming you have another extension somewhere similar to this. You have to add the support for alpha there

// we cannot name the param "alpha" because of a name collision
convenience init(red: Int, green: Int, blue: Int, a: Int = 255) {
    self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: CGFloat(a) / 255)
}

convenience init(hex:Int) {
    self.init(red:(hex >> 16) & 0xff, green:(hex >> 8) & 0xff, blue:hex & 0xff, a:(hex >> 24) & 0xff)
}

(assuming alpha is the first component).

If you want alpha to be just an additional decimal number

convenience init(red: Int, green: Int, blue: Int, a: CGFloat = 1.0) {
    self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: a)
}

convenience init(hex:Int, a: CGFloat = 1.0) {
    self.init(red:(hex >> 16) & 0xff, green:(hex >> 8) & 0xff, blue:hex & 0xff, a: a)
}