VB.NET Convert List to StringConvert Lists and Strings using the String.Join Function and StringBuilder.
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.
Useful functions. 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.
Tip You can compile this in older .NET versions by using vals.ToArray() as the second argument to String.Join.
VB.NET program that uses String.Join
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
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.
Then We invoke the ToString function on the StringBuilder instance to acquire the result String.
Note The resulting string has a delimiter at the end—this may not be desirable.
VB.NET program that uses StringBuilder
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
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.
Note You will need a newer version of .NET to have the ToList extension method.
Finally The example demonstrates that the result List has the correct three elements.
VB.NET program that uses Split
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
Summary. 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.
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