VB.NET Convert List to StringThese VB.NET programs convert Lists and strings. They use String.Join and StringBuilder.
Convert List, String.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.
Example.To start, we have a List of Strings with three elements in it. With the newer versions of .NET, such as .NET 4.0, you can call String.Join directly on a List. This example takes each String element and joins them with commas.
Note: There is no comment at the end, only between two elements in the list at each location.
Tip: You can make this example compile in .NET 3.5 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 three strings. Dim vals As List(Of String) = New List(Of String) vals.Add("dot") vals.Add("net") vals.Add("perls") ' Use string join function that receives IEnumerable. Dim value As String = String.Join(",", vals) Console.WriteLine(value) End Sub End Module Output dot,net,perls|
Example 2.You can also use the StringBuilder type to transform your List of any type of element into a single string. We use a For-Each looping construct and append the iteration variable and also a delimiter "|" after each element.
Then: We invoke the ToString function on the StringBuilder instance to acquire the result String.StringBuilder Examples
Please note: The result 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 Output thank|you|very|much||
Example 3.Continuing on, you often need to take a String and convert it into a collection such as a List of Strings. To do this, you can invoke the Split function on the String input, and then call the ToList extension method on the array you get.Split
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 Output 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, as the code is well-tested and already developed. But using StringBuilder can also be effective.
Dot Net Perls
|© 2007-2019 Sam Allen. All rights reserved. Written by Sam Allen, firstname.lastname@example.org.|