UISlider value can't be accessed by function in ViewController - ios

Question

I get an error saying "EXC_BAD_INSTRUCTION..." in reference to attempting to use redSlider.value to set a value for a property of my "Color" type from another file.(also pasted below)
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBOutlet weak var colorView: UIView!
#IBOutlet weak var redSlider: UISlider!
#IBOutlet weak var greenSlider: UISlider!
#IBOutlet weak var blueSlider: UISlider!
func updateCurrentColor() {
var currentColor = Color(red: redSlider.value, green: greenSlider.value, blue: blueSlider.value)
print("CurrentColor updated!!!")
}
}
And here is my "Color" Type(in another file):
import Foundation
struct Color {
var red = Float()
var green = Float()
var blue = Float()
}
Here is my ViewController
I call updateCurrentColor() from main.swift
import Foundation
import UIKit
ViewController().updateCurrentColor()

Answer 1

ViewController() creates a new view controller object. Since you don't present it on the screen, its outlets never get initialized. That means that the ! on the end of redSlider: UISlider! is a lie.
Even if it didn't crash, updating the color on something you're not putting on the screen doesn't sound very useful.
Use the ViewController you already have instead of creating a new one.