Question

您好我正在尝试在VB.Net中反转字符串而不使用任何内置函数。这是我的c

Dim word As String

Dim reversed As String
Dim x As String
Dim count As Integer = Len(word)
Function reverse(ByVal value As String) As String
    Do
        For i = count To 1 Step -1
            x = Mid(word, i + 1, 1)
            reversed = x
        Next
    Loop Until count = 1
    Return reversed
End Function
Sub Main()
    Dim word As String

    Console.WriteLine("Enter word")
    word = Console.ReadLine()

    Console.WriteLine(reverse(word))
    Console.ReadLine()
End Sub

但是我的代码无效。有人可以解释我错在哪里吗？

Answer 1

你的问题看起来像是在这个循环中：

For i = count To 1 Step -1
    x = Mid(word, i + 1, 1)
    reversed = x
Next

您需要将 x追加到reversed，而不是替换它，例如使用

将reversed初始化为空字符串

Dim reversed As String = String.Empty

然后将循环中的行更改为

reversed = String.Concat(reversed, x)

更好的是，StringBuilder类是理想，可以像你一样重复添加字符串。

Answer 2

您可以使用 LINQ 扩展程序。

Dim str As String = "Hello World!"

Dim reversed As String = String.Join("", str.Reverse)

Debug.WriteLine(reversed)

如果你想要更多＆＃34;质朴的＆＃34;接近：

''' <summary>
''' Reverses the characters of the specified string.
''' </summary>
''' <param name="value">The string to reverse.</param>
''' <returns>the reversed string.</returns>
Public Shared Function Reverse(ByVal value As String) As String

    Dim sb As New System.Text.StringBuilder

    For Each c As Char In value
        sb.Insert(0, c)
    Next c

    Return sb.ToString

End Function

反向字符串q

2 个答案: