作业指导

Question

这是我的编程入门课的第三周，我被卡住了。我可以让它运行，我只是不能输入超过1个数字。这是一个vb控制台应用程序。

Module Module1

    Sub Main()
        Dim highestNumber As Integer = -1000000000
        Dim lowestNumber As Integer = 100000000
        Dim userInput As Integer

        Console.WriteLine("Input your numbers and when you are done enter -99.")
        Console.WriteLine("The app will then give the highest and lowest numbers entered.")
        userInput = Console.ReadLine()

        While userInput <> "-99"
            If userInput >= highestNumber Then
                highestNumber = userInput
            ElseIf userInput <= lowestNumber Then
                lowestNumber = userInput
            End If
        End While

        Console.WriteLine("The highest number you entered is: " & highestNumber)
        Console.WriteLine("The lowest number you entered is: " & lowestNumber)

        Console.ReadLine()

    End Sub

End Module

Answer 1

在循环开始之前，您只执行一次ReadLine，所以您只能输入一个数字。按照目前的情况，如果不输入-99，那么就会有一个无限循环，因为您不能在循环中更改userInput。

您需要将userInput = Console.ReadLine()的副本放在While循环的末尾，以便可以输入新值并重新执行逻辑。

此外，您还可以从测试中删除=符号。除非新数字实际更高/更低，否则不会更改最高/最低值。

Answer 2

将这一行移动到while循环中

userInput = Console.ReadLine()

Answer 3

这是我的解决方案。它检查用户的输入，如果不是整数，他们可以重试或输入-99并退出...您还可以通过更改显示2的几个位置来更改用户输入的数字数量，或者声明一个变量并设置它，然后使用它……

 Public Sub Main()

    Dim userInput As Integer = 0
    Dim lstInteger As New List(Of Integer)

    Console.WriteLine("Input your numbers and when you are done enter -99." & Environment.NewLine & "The app will then give the highest and lowest numbers entered.")

    Do Until userInput = -99
        If Integer.TryParse(Console.ReadLine(),userInput) AndAlso userInput <> -99 Then
            lstInteger.Add(userInput)
            If lstInteger.Count = 2 Then Exit Do
            userInput = 0
            If Integer.TryParse(Console.ReadLine(), userInput) AndAlso userInput <> -99 Then
                lstInteger.Add(userInput)
                If lstInteger.Count = 2 Then Exit Do
            Else
                If userInput = -99 Then Exit Do Else Console.WriteLine("Please enter a number.")
            End If
        Else
            If userInput <> - 99 AndAlso userInput = 0 Then 
                Console.WriteLine("Please enter a number.")
            Else
                Exit Do
            End If 
        End If
    Loop

    If lstInteger.Count = 2 Then 
       Console.WriteLine("The highest number you entered is: " & lstInteger.Max.ToString)
       Console.WriteLine("The lowest number you entered is: " & lstInteger.Min.ToString)
    End If 

    Console.ReadLine()          

End Sub