Slider Not Excepting Current Default Value in Swift - function

Question

Sorry to do this again, but my code has yet ANOTHER problem. When I run the program in the simulator, if I move the slider from its default position and hit the submit button, it will calculate the mpg. However, if I leave the slider at its default position of 500, then choose how many gallons I used (like normal), and hit "Submit", I get a value of 0.0 for the mpg. I know that it isn't right. My instructor suggested that I put the values that were originally in the milesDrivenSliderValueChanged function and put them in their own function. When I did, I got a bunch of errors. I fixed them, but I still get the same results. I would like to know what I am doing wrong.
Here is my code for the slider and the new function it calls:
class SecondViewController: UIViewController,UIPickerViewDataSource,UIPickerViewDelegate
{
var BlopSoundURL = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("Blop", ofType: "mp3")!)
var soundAudioPlayer = AVAudioPlayer()
var miles = 0.0
var gallonsUsed = 0.0
var mpg: Double = 0.0
var currentSelection: Double?
#IBOutlet weak var milesDrivenLabel: UILabel!
#IBOutlet weak var milesDrivenSlider: UISlider!
#IBAction func milesDrivenSliderValueChanged(sender: UISlider)
{
currentSelection = Double(sender.value)
sliderMoved()
}
func sliderMoved()
{
milesDrivenLabel.text = "\(round(currentSelection! * 100) / 100)"
println("Current Selection = \(currentSelection)")
miles = currentSelection!
}
The rest of the code is for the Picker (which I don't think has any problems), the submit button, and the other functions:
#IBOutlet weak var gallonsUsedPicker: UIPickerView!
let pickerData = [1,2,3,4,5,6,7,8,9,10,11,
12,13,14,15,16,17,18,19,20,21,
22,23,24,25,26,27,28,29,30,31,
32,33,34,35,36,37,38,39,40,41,
42,43,44,45,46,47,48,49,50,51,
52,53,54,55,56,57,58,59,60,61,
62,63,64,65,66,67,68,69,70,71,
72,73,74,75,76,77,78,79,80,81,
82,83,84,85,86,87,88,89,90,91,
92,93,94,95,96,97,98,99,100]
#IBAction func submitButton(sender: UIButton)
{
soundAudioPlayer.play()
let rowValue = gallonsUsedPicker.selectedRowInComponent(0) + 1
gallonsUsed = Double(rowValue)
mpg = Double(round((miles * 100) / gallonsUsed) / 100)
let message = "Your MPG is approximately: \(mpg)."
let alert = UIAlertController(
title: "Your MPG",
message: message,
preferredStyle: .Alert)
let action = UIAlertAction(
title: "Ok",
style: .Default,
handler: nil)
alert.addAction(action)
presentViewController(alert, animated: true, completion: nil)
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return "\(row+1)"
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return 100
}
override func viewDidLoad()
{
super.viewDidLoad()
gallonsUsedPicker.dataSource = self
gallonsUsedPicker.delegate = self
soundAudioPlayer = AVAudioPlayer(contentsOfURL: BlopSoundURL, error: nil)
// Do any additional setup after loading the view, typically from a nib.
} // End of viewDidLoad
This is really frustrating. It's probably a simple fix, but I just can't see it. I spent 3 hours on this last night and 2 more hours just this morning. Any help would be appreciated. Thank you for your time and efforts.

Answer 1

I'm a doofus. I just had to change miles to 500, instead of zero. Now it works. Sorry, guys.