Convert List, String

In VB.NET programs, strings and lists are often converted. A List of Strings can be combined into one String. Alternatively a String can be converted into a List.

Some functions, including String.Join and Split, are useful for this purpose. We demonstrate them in these VB.NET examples.

First example

We have a List of 2 Strings. With newer versions of .NET, you can call String.Join directly on a List. This example takes each String element and joins them with commas.

Module Module1
    Sub Main()
        ' Create list of 2 strings.
        Dim vals As List(Of String) = New List(Of String)
        vals.Add("cat")
        vals.Add("paws")

        ' Use string join function that receives IEnumerable.
        Dim value As String = String.Join(",", vals)
        Console.WriteLine(value)
    End Sub
End Module
cat,paws

Example 2

You can also use StringBuilder to transform your List of any type of element into a single string. We use For-Each and append each string and a delimiter.

Imports System.Text

Module Module1
    Sub Main()
        ' Example list.
        Dim vals As List(Of String) = New List(Of String)
        vals.Add("thank")
        vals.Add("you")
        vals.Add("very")
        vals.Add("much")

        ' Create StringBuilder.
        ' ... Append all items in For Each loop.
        Dim builder As StringBuilder = New StringBuilder()
        For Each val As String In vals
            builder.Append(val).Append("|")
        Next

        ' Convert to string.
        Dim res = builder.ToString()
        Console.WriteLine(res)
    End Sub
End Module
thank|you|very|much|

Example 3

You often need to convert a String into a collection (such as a List of Strings). You can Split the String, and then call ToList() on the resulting array.

Module Module1
    Sub Main()
        ' Input string.
        Dim value As String = "Dot-Net-Perls"

        ' Split on hyphen.
        Dim arr() As String = value.Split("-")

        ' Convert to List.
        Dim vals As List(Of String) = arr.ToList()

        ' Display each List element.
        For Each val As String In vals
            Console.WriteLine(val)
        Next
    End Sub
End Module
Dot
Net
Perls

We converted between Lists and Strings. Typically, using String.Join and Split are the most effective ways to perform these conversions. But StringBuilder can also be effective.