How to make a random color with Swift

Question

How I can make a random color function using Swift?

import UIKit

class ViewController: UIViewController {

    var randomNumber = arc4random_uniform(20)
    var randomColor = arc4random()

    //Color Background randomly
    func colorBackground() {

        // TODO: set a random color
        view.backgroundColor = UIColor.yellow

    }
}

Answer 1

You're going to need a function to produce random CGFloats in the range 0 to 1:

extension CGFloat {
    static func random() -> CGFloat {
        return CGFloat(arc4random()) / CGFloat(UInt32.max)
    }
}

Then you can use this to create a random colour:

extension UIColor {
    static func random() -> UIColor {
        return UIColor(
           red:   .random(),
           green: .random(),
           blue:  .random(),
           alpha: 1.0
        )
    }
}

If you wanted a random alpha, just create another random number for that too.

You can now assign your view's background colour like so:

self.view.backgroundColor = .random()