Create many UISliders that update a related label using one function - ios

Question

I have an experience where a user is rating a product, they do this by dragging sliders. Each slider has a related UILabel for the title and a UILabel for the value. I would like to avoid creating 12 functions, one for each slider and the associated label. I am new to development generally. I am guessing a class or an Array would be useful here, but am not sure how to use either. Here's the code that just updates the one value, and I know why that is, I'm just hoping to avoid declaring 12 variables for the value and 12 functions for each one.
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var slider1: UISlider!
#IBOutlet weak var value1: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func sliderSlide(sender: UISlider) {
value1.text = round(sender.value*100).description
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}

Answer 1

Well,you can use Outlet Collection and 'tag',
Drag every label into a same Outlet Collection
Drag every Slider IBAction into a same function
Then set the tag of slider as the index of label in Outlet Collection.
For example,you first drag labelA to Collection,then the tag is 0
Then all the code
import UIKit
class ViewController: UIViewController {
#IBOutlet var labels: [UILabel]!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func sliderSlide(sender: UISlider) {
let index = sender.tag
let label = labels[index]
label.text = round(sender.value*100).description
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}

Answer 2

You can connect more than one slider to the same function. That's the purpose of the sender argument. You can do a switch statement on the pointer in swift, or by a set tag of the slider if you prefer. If it's all updating the same label, why even care which slider is updating?

Answer 3

I can think of two ways of doing this. Make a custom view controller that looks exactly the same as the code you have. It will have the slider and label as subviews. Then you'd only have 12 container views on your storyboard (not the greatest).
The other way would be using IBOutletCollections. These are what they sound like, collections of IBOutlets. Assign each slider that you place on the storyboard a unique tag from 0-11 (this is done under the attributes inspector). The tag will act as an index for the values array. Make sure that when you add each label to the collection, you do it in the correct order (it does matter!). Using IBOutletCollections, your code would look like this:
class ViewController: UIViewController {
#IBOutlet weak var sliders: [UISlider]!
#IBOutlet weak var values: [UILabel]!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func sliderSlide(sender: UISlider) {
values[sender.tag].text = round(sender.value*100).description
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}