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iOS Build a Simple iPhone App with Swift Improving Our User Interface Random Colors

Nathalie Dory
Nathalie Dory
2,912 Points
Posted by Nathalie Dory
Nathalie Dory
2,912 Points

Why do you add () after declaring a property and method in a class?

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var quickGermanLabel: UILabel!

let factProvider = FactProvider() let colorProvider = backgroundColorProvider()

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    quickGermanLabel.text = factProvider.randomFact()



}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

@IBAction func showNewFact() {

    let newColor = UIColor(red: 223/255.0, green: 86/255.0, blue: 94/255.0, alpha: 1.0)

    view.backgroundColor = newColor

quickGermanLabel.text = factProvider.randomFact()

}

}

1 Answer

kols
kols
27,007 Points
kols
kols
27,007 Points

For anyone curious about this still, I added a more detailed answer to the same question on a different post earlier today :thumbsup: Hopefully that can help!

In short, when creating an instance of an object (class, struct, etc.), you must initialize it with values for the object's stored properties. When the class/struct has already been given default values (as in the case of this video — the structs both have an array with values), you just leave the parentheses empty (unless you want to provide alternative values for some reason).

For example:

// Given the following struct ('Vehicle') create an instance of 'Vehicle', and store it in a constant named 'myCar':

struct Vehicle {
    var numberOfWheels = 4
    var numberOfDoors = 2
}

let myCar = Vehicle()

For more, you may want to review classes and structures in the Swift Documentation to clear up any remaining questions about creating instances. Happy Coding! :v: