How to: Create Strings Using a StringBuilder in Visual Basic
This example constructs a long string from many smaller strings using the StringBuilder class. The StringBuilder class is more efficient than the &= operator for concatenating many strings.
Example
The following example creates an instance of the StringBuilder class, appends 1,000 strings to that instance, and then returns its string representation.
Private Function StringBuilderTest() As String
Dim builder As New System.Text.StringBuilder
For i As Integer = 1 To 1000
builder.Append("Step " & i & vbCrLf)
Next
Return builder.ToString
End Function