用VB.NET中的一行代码替换字符串中的多个字符

Question

使用VB.NET我希望能够用一行代码替换字符串中的一系列字符。

即，是这样的：

Dim charsToReplace as string = "acegi" 
Dim stringToBeReplaced as string = "abcdefghijklmnop" 

charsToReplace.ToArray().ForEach(Function (c) stringTobeReplaced = stringTobeReplaced.Replace(c, "")) 

但是，这是行不通的。

下不工作，但我不希望字符串是类级变量：

Sub Main() 
    Dim toReplace As String = "acegikmoq" 

    Console.WriteLine(mainString) 
    Dim chars As List(Of Char) = toReplace.ToList() 
    chars.ForEach(AddressOf replaceVal) 

    Console.WriteLine(mainString) 
    Console.ReadLine() 
End Sub 

Dim mainString As String = "this is my string that has values in it that I am going to quickly replace all of..." 

Sub replaceVal(ByVal c As Char) 
    mainString = mainString.Replace(c, "") 
End Sub 

可以这样做？

Answer 1

String类有一个替换方法来做到这一点。你可以这样使用它：

YourString = YourString.Replace("OldValue", "NewValue") 

Answer 2

如果我正确读了这个，你试图从字符串中去掉一个字符列表。这非常适合RegEx。

Console.WriteLine(Regex.Replace("abcdefghijklmnop", "[acegi]", string.Empty)) 

（你需要导入System.Text.RegularExpressions）

Answer 3

我建议乔恩·加洛韦的做法，正则表达式是适当的方法，以及未来开发商将感谢你的:) - 尽管Linq也不是一个难以解决的问题。下面是一些（未经测试）C＃代码来做到这一点：

string stringToBeReplaced = "abcdefghijklmnop"; 
string charsToReplace = "acegi"; 
stringToBeReplaced = new String(stringToBeReplaced.Where(c => !charsToReplace.Any(rc => c == rc)).ToArray()); 

我怀疑这可能是代码执行会稍微好一点，然后正则表达式等价的，如果性能是一个问题。

Answer 4

正则表达式的方法是最适合的，但我真的需要说的是：

请，为维护开发商的爱，不要挂断上得到这个下降到1行代码。一个方法调用是你的真正目标，如果你最终只是将一堆调用堆成一行来表示它是单行的，那么你就是在自己的脚下开枪。

Answer 5

我不相信Bittercode，因为他说LINQ将超越正则表达式。 所以我做了一个小测试只是为了确定。如何做到这一点

三个例子：

Dim _invalidChars As Char() = New Char() {"j"c, "a"c, "n"c} 
Dim _textToStrip As String = "The quick brown fox jumps over the lazy dog" 

Private Sub btnStripInvalidCharsLINQ_Click(sender As System.Object, e As System.EventArgs) Handles btnStripInvalidCharsLINQ.Click 
    Dim stripped As String = String.Empty 
    Dim sw As Stopwatch = Stopwatch.StartNew 
    For i As Integer = 0 To 10000 
     stripped = _textToStrip.Where(Function(c As Char) Not _invalidChars.Contains(c)).ToArray 
    Next 
    sw.Stop() 

    lblStripInvalidCharsLINQ.Text = _stripped & " - in " & sw.Elapsed.TotalMilliseconds & " ms" 
End Sub 

Private Sub btnStripInvalidCharsFOR_Click(sender As System.Object, e As System.EventArgs) Handles btnStripInvalidCharsFOR.Click 
    Dim stripped As String = String.Empty 
    Dim sw As Stopwatch = Stopwatch.StartNew 
    stripped = _textToStrip 
    For i As Integer = 0 To 10000 
     For Each c As Char In _invalidChars 
      stripped = stripped.Replace(c, "") 
     Next 
    Next 
    sw.Stop() 

    lblStipInvalidcharsFor.Text = stripped & " - in " & sw.Elapsed.TotalMilliseconds & " ms" 
End Sub 

Private Sub btnStripInvalidCharsREGEX_Click(sender As System.Object, e As System.EventArgs) Handles btnStripInvalidCharsREGEX.Click 
    Dim stripped As String = String.Empty 
    Dim sw As Stopwatch = Stopwatch.StartNew 
    For i As Integer = 0 To 10000 
     stripped = Regex.Replace(_textToStrip, "[" & New String(_invalidChars) & "]", String.Empty) 
    Next 
    sw.Stop() 

    lblStripInvalidCharsRegex.Text = stripped & " - in " & sw.Elapsed.TotalMilliseconds & " ms" 
End Sub 

结果：

所以，for循环与outperformes与string.replace所有其他方法。

因此，我会对字符串对象做一个扩展函数。

Module StringExtensions 
<Extension()> _ 
Public Function ReplaceAll(ByVal InputValue As String, ByVal chars As Char(), replaceWith As Char) As String 
    Dim ret As String = String.Empty 
    For Each c As Char In chars 
     ret.Replace(c, replaceWith) 
    Next 
    Return ret 
End Function 

然后，你可以使用这个功能不错，可读取一行：

_textToStrip.ReplaceAll(_invalidChars, CChar(String.Empty)) 

Answer 6

什么是重复行语句，如果你真的想使用该代码的最佳方式：

Sub Main() 

    Dim myString As String = Nothing 
    Dim finalString As String = Nothing 
    Console.Write("Please enter a string: ") 'your free to put anything 
    myString = Console.ReadLine() 
    finalString = myString.Replace("0", "") 
    myString = finalString 
    finalString = myString.Replace("1", "") 
    myString = finalString 
    finalString = myString.Replace("2", "") 
    myString = finalString 
    finalString = myString.Replace("3", "") 
    myString = finalString 
    finalString = myString.Replace("4", "") 
    myString = finalString 
    finalString = myString.Replace("5", "") 
    myString = finalString 
    finalString = myString.Replace("6", "") 
    myString = finalString 
    finalString = myString.Replace("7", "") 
    myString = finalString 
    finalString = myString.Replace("8", "") 
    myString = finalString 
    finalString = myString.Replace("9", "") 
    Console.WriteLine(finalString) 
    Console.ReadLine() 
End Sub 

例如：如果键入：012ALP456HA90BET678输出将是：ALPHABET。

Answer 7

Public Function SuperReplace(ByRef field As String, ByVal ReplaceString As String) As String 
    ' Size this as big as you need... it is zero-based by default' 
    Dim ReplaceArray(4) As String 

    'Fill each element with the character you need to replace' 

    ReplaceArray(0) = "WARD NUMBER " 
    ReplaceArray(1) = "WN " 
    ReplaceArray(2) = "WARD NO " 
    ReplaceArray(3) = "WARD-" 
    ReplaceArray(4) = "WARD " 

    Dim i As Integer 
    For i = LBound(ReplaceArray) To UBound(ReplaceArray) 
    field = Replace(field, ReplaceArray(i), ReplaceString) 
    Next i 
    SuperReplace = field 
End Function