swift - 我想让应用程序在朋友之间分摊账单

Question

我想做一个少屏幕的计算器，第一个屏幕“我们有多少人”，第二个屏幕“账单”，然后在第三个屏幕“除法账单到人数的结果”，但它给了我一个致命的最后 Xcode 中的错误：

@IBAction func equal(_ sender: Any)
...
secondInput = Double(adam.text!)! 
...

代码：

var plusAndMinus = 0
class ViewController234: UIViewController {


    @IBOutlet weak var adam: UILabel!

    @IBAction func plus(_ sender: Any) {
        plusAndMinus += 1
         adam.text = "\(plusAndMinus)"
      }
      @IBAction func minus(_ sender: Any) {
          if(plusAndMinus != 0 ) {
              plusAndMinus -= 1
          }
         adam.text = "\(plusAndMinus)"
      }
//Next Screen => Total Amount

    var first = 0.0                  //Display LABEL
    // second input = adam
    var function = ""
    var result = 0.0
    var userInput = ""



    @IBOutlet weak var Display: UILabel!

    @IBAction func numberOne(_ sender: Any) {

        Display.text = ""
        userInput += "1"
        Display.text! += userInput
    }

    @IBAction func numberTwo(_ sender: Any) {

        Display.text = ""
        userInput += "2"
        Display.text! += userInput

    }

    @IBAction func numberThree(_ sender: Any) {
        Display.text = ""
        userInput += "3"
        Display.text! += userInput
        }

    @IBAction func numberFour(_ sender: Any) {
        Display.text = ""
        userInput += "4"
        Display.text! += userInput
        }

    @IBAction func numberFive(_ sender: Any) {
        Display.text = ""
        userInput += "5"
        Display.text! += userInput
    }

    @IBAction func numberSix(_ sender: Any) {
        Display.text = ""
        userInput += "6"
        Display.text! += userInput
    }

    @IBAction func numberSeven(_ sender: Any) {
        Display.text = ""
        userInput += "7"
        Display.text! += userInput
    }

    @IBAction func numberEight(_ sender: Any) {
        Display.text = ""
        userInput += "8"
        Display.text! += userInput
    }

    @IBAction func numberNine(_ sender: Any) {
        Display.text = ""
        userInput += "9"
        Display.text! += userInput
    }

    @IBAction func numberZero(_ sender: Any) {
        Display.text = ""
        userInput += "0"
        Display.text! += userInput
    }
    @IBAction func clear(_ sender: Any) {
        first = 0.0
        function = ""
        userInput = ""
        result = 0.0
        Display.text = ""
    }

    @IBAction func virgule(_ sender: Any) {
        Display.text = ""
        userInput += ","
        Display.text! += userInput
    }

    @IBAction func equal(_ sender: Any) {
        function = "/"
        var firstInput = 0.0
        firstInput = Double(first)
        var secondInput = 0.0
        secondInput = Double(adam.text!)!         //Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value

        result = firstInput / secondInput
        lastDisplay.text = String(result)
    }

    @IBOutlet weak var lastDisplay: UILabel!

标签： swiftcalculatorfatal-error