Join. This VB.NET function combines many string elements into a single string. It acts on an array or List (we do not need to convert a List to an array first).
By using the Join function, we collapse these collections into String instances. This can help with file handing, or for storage of data in a database.
First example. This program creates an array of 3 strings. Then, we invoke the String.Join function on this array with the first argument being a string literal.
And The resulting string has the delimiter placed between all the elements—but not at the start or end.
Info Join requires a delimiter character and a collection of strings. It places this separator in between the strings in the result.
Module Module1
Sub Main()
' Three-element array.
Dim array(2) As String
array(0) = "Dog"
array(1) = "Cat"
array(2) = "Python"' Join array.
Dim result As String = String.Join(",", array)
' Display result.
Console.WriteLine(result)
End Sub
End ModuleDog,Cat,Python
Example 2. You can specify the elements you want to join directly inside the String.Join call. Just pass more than 2 arguments to the String.Join function.
Tip Arguments after the first are joined together—the first is the delimiter.
Module Module1
Sub Main()
' Join array.
Dim result As String = String.Join("-", "Dot", "Net", "Perls")
' Display result.
Console.WriteLine(result)
End Sub
End ModuleDot-Net-Perls
Example 3. You can also join objects together into a single string. In the VB.NET language, each object can be converted into a String.
Info This String.Join function converts each object to a string and then joins those strings together.
Module Module1
Sub Main()
' Join array.
Dim result As String = String.Join("/", 1, 2, 3, "VB.NET")
' Display result.
Console.WriteLine(result)
End Sub
End Module1/2/3/VB.NET
Join List. What should you do if you need to join the elements of a List? We can just pass the List directly to Join. This feature was added in newer versions of .NET.
Module Module1
Sub Main()
' List.
Dim list As List(Of String) = New List(Of String)
list.Add("Dot")
list.Add("Net")
list.Add("Perls")
' Join list.
Dim result As String = String.Join("*", list)
' Display result.
Console.WriteLine(result)
End Sub
End ModuleDot*Net*Perls
A summary. The String.Join function provides the opposite effect of the Split function. It takes a collection of elements and combines them into a single string separated by a delimiter.
Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.
Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
This page was last updated on Mar 26, 2022 (edit link).
