Use StringBuilder to reverse a string : StringBuilder « Data Type « VB.Net Tutorial

Imports System

public class Test
   public Shared Sub Main
        Dim data As String = "abcdefgh"


        Dim objSB As New Text.StringBuilder
        Dim intLength As Integer = Len(data)
        Dim intChar As Integer
        Dim chr As Char
        Dim objTS As TimeSpan
        Dim dteStart As Date

        objSB.Capacity = intLength
        objSB.Append(data)
        dteStart = Now()

        For intChar = 0 To CInt(objSB.Length / 2 - 1)
            chr = objSB.Chars(intChar)
            objSB.Chars(intChar) = objSB.Chars(intLength - intChar - 1)
            objSB.Chars(intLength - intChar - 1) = chr
        Next

        objTS = Now().Subtract(dteStart)
        Console.WriteLine(objTS.ToString)
        Console.WriteLine(objSB.ToString)
   End Sub
   
End class

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2.40.StringBuilder
	2.40.1.	Demonstrating StringBuilder class constructors
	2.40.2.	StringBuilder: Insert string, Append and Replace
	2.40.3.	Append Char to StringBuilder
	2.40.4.	Demonstrating StringBuilder Append methods
	2.40.5.	StringBuilder AppendFormat
	2.40.6.	StringBuilder.AppendFormat: {0:D} is ${1: #,###.00}
	2.40.7.	Replace method.
	2.40.8.	Insert method of StringBuilder
	2.40.9.	StringBuilder: Length, Capacity, EnsureCapacity
	2.40.10.	Use StringBuilder Indexer
	2.40.11.	Demonstrating methods Insert and Remove of the StringBuilder class
	2.40.12.	Demonstrating method Replace
	2.40.13.	Use StringBuilder to reverse a string
	2.40.14.	StringBuilder.ToStrings
	2.40.15.	Performance difference between String and StringBuilder