针对不同的数组 vb.net 检查 char 数组

Question

我正在尝试检查用户输入的内容是否在字母数组中。然后将字母转换为莫尔斯电码，即莫尔斯数组。我必须使用 char 数组按顺序显示用户输入，但它按字母顺序显示莫尔斯电码。如何正确停止显示？提前致谢。

    Dim strCode As String = txtCode.Text.ToUpper 'What the user enters must be letters it can also be - or =
    Dim strText() As Char = strCode.ToCharArray

    Dim strLetter() As String = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"}
    Dim strMorse() As String = {"*=", "=***", "=*=*", "=**", "*", "**=*", "==*", "****", "**", "*===", "=*=", "*=**", "==", "=*", "===", "*==*", "==*=", "*=*", "***", "=", "**=", "***=", "*==", "=**=", "=*==", "==**"}

    For Each letter As Char In strText
        For x As Integer = 0 To strLetter.Length - 1
            If strCode.Contains(strLetter(x)) Then
                MessageBox.Show(strMorse(x))
            End If
        Next
    Next
End Sub

Answer 1

如果您使用简单的代码（例如“BA”）单步执行代码，您会看到逻辑错误。您永远不会将外部循环中的字母与内部循环中的任何内容进行比较。相反，您的 If 语句是在询问“嘿，我的输入是否包含 strLetter 数组中的第一个字母？”是的，“A”在那里（即使它不是第一个字符）。

如果字母在范围内（在 A 和 Z 之间），则分配的更简单的解决方案是使用字母的 ASCII 值与“A”的偏移量。这消除了定义strLetter 的需要。您还可以省略将输入文本转换为字符数组。字符串已经让您可以枚举字符。

Dim strCode As String = txtCode.Text.ToUpper 'What the user enters must be letters it can also be - or =

Dim strMorse() As String = {"*=", "=***", "=*=*", "=**", "*", "**=*", "==*", "****", "**", "*===", "=*=", "*=**", "==", "=*", "===", "*==*", "==*=", "*=*", "***", "=", "**=", "***=", "*==", "=**=", "=*==", "==**"}

For Each letter As Char In strCode
  If letter >' "A"c AndAlso letter <= "Z"c Then
    MessageBox.Show(strMorse(AscW(letter) - AscW("A"c)))
  End If
Next

Answer 2

只需使用字典并遍历字符串中的所有字符，您就不必担心查找字符并以正确的顺序翻译它们。使用字母作为键，使用莫尔斯电码作为值...然后你可以像这样浏览文本并翻译每个字母：

    Dim translate As New Dictionary(Of String, String) From {{" ", " "}, _
                                                             {"A", "*="}, _
                                                             {"B", "=***"}, _
                                                             {"C", "=*=*"}, _
                                                             {"D", "=**"}, _
                                                             {"E", "*"}, _
                                                             {"F", "**=*"}, _
                                                             {"G", "==*"}, _
                                                             {"H", "****"}, _
                                                             {"I", "**"}, _
                                                             {"J", "*==="}, _
                                                             {"K", "=*="}, _
                                                             {"L", "*=**"}, _
                                                             {"M", "=="}, _
                                                             {"N", "=*"}, _
                                                             {"O", "==="}, _
                                                             {"P", "*==*"}, _
                                                             {"Q", "==*="}, _
                                                             {"R", "*=*"}, _
                                                             {"S", "***"}, _
                                                             {"T", "="}, _
                                                             {"U", "**="}, _
                                                             {"V", "***="}, _
                                                             {"W", "*=="}, _
                                                             {"X", "=**="}, _
                                                             {"Y", "=*=="}, _
                                                             {"Z", "==**"}}
    Dim translatedMsg As String = Nothing
    For Each c As Char In txtCode.Text.ToUpper
        translatedMsg += translate(c) & " "
    Next
    Debug.Print(translatedMsg.TrimEnd)

    'Output for "Hello World": **** * *=** *=** ===   *== === *=* *=** =**

---

编辑：嗯，从一个值到它的键倒退不如从一个键到另一个值那样干净，因为它没有本地函数，但是 Linq 可以很好地解决这个问题。 .如果我说实话，我一开始并没有考虑将空间转换回来。我可能会在字典中添加一个特殊字符作为空格，这会使翻译更容易。但尽管如此，为了举例，我会坚持我的第一个例子，这就是你如何将消息翻译回来。我再次使用了“Hello World”，为了解决空格问题，我只是用下划线代替空格，这样我就可以正确解码消息（另外，显然你失去了大写/小写的区别，因为莫尔斯电码不区分二）：

    Dim strMorseMsg As String = "**** * *=** *=** ===   *== === *=* *=** =**"

    strMorseMsg = strMorseMsg.Replace("   ", " _ ") 'substitution here to distinguish spaces between words from the space between letters
    Dim aryMorseMsg() As String = strMorseMsg.Split(CChar(" "))

    Dim originalMessage As String = Nothing
    For Each code As String In aryMorseMsg
        If code.Equals("_") Then 'here's where the underscore helps branch our logic between adding a space and adding a letter
            originalMessage += " "
        Else
            originalMessage += translate.FirstOrDefault(Function(x) x.Value = code).Key
        End If
    Next
    MsgBox(originalMessage)

    'Outputs "HELLO WORLD"

Answer 3

Sub Main()
    Dim codes() As String = { _
        "*=", "=***", "=*=*", "=**", "*", "**=*", "==*", "****", "**", _
        "*===", "=*=", "*=**", "==", "=*", "===", "*==*", "==*=", "*=*", _
        "***", "=", "**=", "***=", "*==", "=**=", "=*==", "==**" _
    }

    Dim input As String = Console.ReadLine().ToUpper()

    ' Convert characters to values that can be used as indexes in the code array
    Dim indexes = input.[Select](Of Integer)(Function(l As Char) Asc(l) - 65)
    ' limit the values to based on the range of possible values
    Dim boundsCheck = indexes.Where(Function(l As Integer) l >= 0 And l <= 26)
    ' map the valid inputs to codes fro myour array
    Dim outCodes = boundsCheck.[Select](Of String)(Function(l As Integer) codes(l))
    ' concatenate the codes into a string and display 
    Console.WriteLine(String.Join(" ", outCodes))
End Sub