'String'在Swift中不能转换为'Int'

Question

在我的添加功能中，answerLabel.text它给我一个错误。它说“字符串”是无法转换为“廉政”，我试图让我从secondStep2了，放在我的函数的参数

//Adding Function 
     changingSignsLabel.text = "+" 
     let firstDenomInTextField:Double! = (firstDenominatorTextField.text as NSString).doubleValue 
     let firstNumInTextField:Double! = (firstNumeratorTextField.text as NSString).doubleValue 
     let firstWholeInTextField:Double! = (firstWholeNumberTextField.text as NSString).doubleValue 

     let secondDenomInTextField:Double! = (secondDenominatorTextField.text as NSString).doubleValue 
     let secondNumInTextField:Double! = (secondNumeratorTextField.text as NSString).doubleValue 
     let secondWholeInTextField:Double! = (secondWholeNumberTextField.text as NSString).doubleValue 

     var firstStep = firstDenomInTextField! * firstWholeInTextField!/firstDenomInTextField! 

     var secondStep = firstStep + firstNumInTextField!/firstDenomInTextField! 

     var thirdStep = secondDenomInTextField! * secondWholeInTextField!/secondDenomInTextField! 
     var fourthStep = thirdStep + secondNumInTextField!/secondDenomInTextField! 

     var calculatedAnswer = (secondStep + fourthStep) 

     answerLabel.hidden = false 

     var firstStep2 = calculatedAnswer/1 
     var secondStep2 = "\(firstStep2 * 10 * 10)" 


     answerLabel.text = printSimplifiedFraction(Numerator: secondStep2) 

我的功能

func printSimplifiedFraction(Numerator numerator: Int, Denominator denominator: Int = 100) 
    { 
     var finalNumerator = numerator; 
     var finalDenominator = denominator; 

     var wholeNumbers:Int = numerator/denominator; 
     var remainder:Int = numerator % denominator; 

     //println("wholeNumbers = \(wholeNumbers), remainder = \(remainder)"); 
     //println("\(denominator) % \(remainder) = \(denominator % remainder)"); 

     if(remainder > 0) 
     { 
      // see if we can simply the fraction part as well 
      if(denominator % remainder == 0) // no remainder means remainder can be simplified further 
      { 
       finalDenominator = denominator/remainder; 
       finalNumerator = remainder/remainder; 
      } 
      else 
      { 
       finalNumerator = remainder; 
       finalDenominator = denominator; 
      } 
     } 

     if(wholeNumbers > 0 && remainder > 0) 
     { 
      // prints out whole number and fraction parts 
      println("Simplified fraction of \(numerator)/\(denominator) = \(wholeNumbers) \(finalNumerator)/\(finalDenominator)"); 
     } 
     else if (wholeNumbers > 0 && remainder == 0) 
     { 
      // prints out whole number only 
      println("Simplified fraction of \(numerator)/\(denominator) = \(wholeNumbers)"); 
     } 
     else 
     { 
      // prints out fraction part only 
      println("Simplified fraction of \(numerator)/\(denominator) = \(finalNumerator)/\(finalDenominator)"); 

     } 
    } 

我的问题我该如何获得接受我的变量的函数？

Answer 1

我相信这是你想要的，首先在你的一dding功能应该是：

var firstStep2 = calculatedAnswer/1 
var secondStep2 = Int(firstStep2 * 10 * 10) 
answerLabel.text = printSimplifiedFraction(Numerator: secondStep2) 

然后打印...方法应该改变这样的（注意，它返回一个字符串）：

func printSimplifiedFraction(Numerator numerator: Int, Denominator denominator: Int = 100) -> String 
{ 
    // I haven't looked into this bit 
    ... 

    if(wholeNumbers > 0 && remainder > 0) 
    { 
     return ("Simplified fraction of \(numerator)/\(denominator) = \(wholeNumbers) \(finalNumerator)/\(finalDenominator)") 
    } 
    else if (wholeNumbers > 0 && remainder == 0) 
    { 
     return ("Simplified fraction of \(numerator)/\(denominator) = \(wholeNumbers)") 
    } 
    else 
    { 
     return ("Simplified fraction of \(numerator)/\(denominator) = \(finalNumerator)/\(finalDenominator)") 
    } 
} 

---

此外，翻翻你的代码我认为你可以相当简化逻辑（我也转换为整数，因为你说你想在评论中）：

let firstDenomInTextField = firstDenominatorTextField.text.toInt() 
let firstNumInTextField = firstNumeratorTextField.text.toInt() 
let firstWholeInTextField = firstWholeNumberTextField.text.toInt() 

let secondDenomInTextField = secondDenominatorTextField.text.toInt() 
let secondNumInTextField = secondNumeratorTextField.text.toInt() 
let secondWholeInTextField = secondWholeNumberTextField.text.toInt() 

var firstStep = firstWholeInTextField! + firstNumInTextField!/firstDenomInTextField! 
var secondStep = secondWholeInTextField! + secondNumInTextField!/secondDenomInTextField! 
var calculatedAnswer = (firstStep + secondStep) 
var numerator = Int(calculatedAnswer * 10 * 10) 
answerLabel.text = printSimplifiedFraction(Numerator: numerator) 

Answer 2

试试这个：

var str:String = "abc" 
var a:Int? = str.toInt() 
if (a != nil) { 
    printSimplifiedFraction(Numerator: str!) 
} 

和返回值添加到您的功能

func printSimplifiedFraction(Numerator numerator: Int, Denominator denominator: Int = 100) ->String { 

    var finalNumerator = numerator; 
    var finalDenominator = denominator; 

    var wholeNumbers:Int = numerator/denominator; 
    var remainder:Int = numerator % denominator; 

    if(remainder > 0) 
    { 
     // see if we can simply the fraction part as well 
     if(denominator % remainder == 0) // no remainder means remainder can be simplified further 
     { 
      finalDenominator = denominator/remainder; 
      finalNumerator = remainder/remainder; 
     } 
     else 
     { 
      finalNumerator = remainder; 
      finalDenominator = denominator; 
     } 
    } 

    var result:String = "Simplified fraction of \(numerator)/\(denominator) = "; 

    if(wholeNumbers > 0 && remainder > 0) 
    { 
     // prints out whole number and fraction parts 
     result += "\(wholeNumbers) \(finalNumerator)/\(finalDenominator)" 
    } 
    else if (wholeNumbers > 0 && remainder == 0) 
    { 
     // prints out whole number only 
     result += "\(wholeNumbers)" 
    } 
    else 
    { 
     // prints out fraction part only 
     result += "\(finalNumerator)/\(finalDenominator)" 

    } 
    println("\(result)") 
    return result 
} 

Answer 3

• 这printSimplifiedFraction没有返回任何值，但你分配给answerLabel。文字，我认为这是问题所在。

• 如果您想分配一个从函数返回的值，请将函数的返回类型添加到函数中并返回一个值。

  func printSimplifiedFraction(Numerator numerator: Int, Denominator denominator: Int = 100) -> String { //add end of your function return yourValue; }

• 检查this link

在你的代码做这样

 var secondStep2 = (firstStep2 * 10 * 10) 
    answerLabel.text = printSimplifiedFraction(Numerator: secondStep2) 

    func printSimplifiedFraction(Numerator numerator: Int, Denominator denominator: Int = 100) -> String 
{ 
    var finalNumerator = numerator; 
    var finalDenominator = denominator; 

    var wholeNumbers:Int = numerator/denominator; 
    var remainder:Int = numerator % denominator; 

    //println("wholeNumbers = \(wholeNumbers), remainder = \(remainder)"); 
    //println("\(denominator) % \(remainder) = \(denominator % remainder)"); 

    if(remainder > 0) 
    { 
     // see if we can simply the fraction part as well 
     if(denominator % remainder == 0) // no remainder means remainder can be simplified further 
     { 
      finalDenominator = denominator/remainder; 
      finalNumerator = remainder/remainder; 
     } 
     else 
     { 
      finalNumerator = remainder; 
      finalDenominator = denominator; 
     } 
    } 


    var returnValue :String 


    if(wholeNumbers > 0 && remainder > 0) 
    { 
     returnValue = "Simplified fraction of \(numerator)/\(denominator) = \(wholeNumbers) \(finalNumerator)/\(finalDenominator)" 
    } 
    else if (wholeNumbers > 0 && remainder == 0) 
    { 
     returnValue = "Simplified fraction of \(numerator)/\(denominator) = \(wholeNumbers)" 
    } 
    else 
    { 
     returnValue = "Simplified fraction of \(numerator)/\(denominator) = \(finalNumerator)/\(finalDenominator)" 

    } 

    return returnValue 
}