问我的变量不会超过8

EN

import UIKit

class ViewController: UIViewController {

// OUTLETS

@IBOutlet weak var score: UILabel!
@IBAction func add(_ sender: Any) {
    add()
}


// VARIABLES

var scoreVar = 0
let levelUpAt = [50, 100, 500, 1000, 5000, 10000, 50000, 100000]
var currentLevel = 1
var toAdd = 1

// OVERRIDES

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

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

// FUNCTIONS

// Below code adds to the score

func add() {
    scoreVar += 1 // Adds 1 to scoreVar
    score.text = "\(scoreVar)"; // Updates text to match
    checkForLevelUp(); // Calls the function defined in the next few days ago
}

// Below code checks if the score meets the next level requirements

func checkForLevelUp() {
    if (scoreVar - 1 < levelUpAt[currentLevel - 1]) { // Complicated math-y if statment
        currentLevel += 1
        toAdd += 1
    }
}
}