Insert. This VB.NET Function places another String somewhere inside the first String. Using the Insert function on the String type, we create a longer String.
Notes, strings. When we call Insert, a new string is created—the existing string is not modified. Insert() also is available on StringBuilder, which does modify an underlying buffer.
Insert example. We call Insert. We must assign a variable to the result of Insert to get the updated string. A new string is created upon the managed heap.
Argument 1 This is the index in the original string where we want to place the new substring. With 4, we place after the fourth char.
Argument 2 This is the new string we want to place inside of the original string. It will be found in the result.
Module Module1
Sub Main()
Dim value As String = "the cat"
Console.WriteLine("INITIAL: {0}", value)
' Use Insert at an index.
Dim result As String = value.Insert(4, "soft ")
Console.WriteLine("INSERT: {0}", result)
End Sub
End ModuleINITIAL: the cat
INSERT: the soft cat
Insert, IndexOf. We can use the IndexOf function with Insert. This demonstrates how we can search for the target index before passing that value to Insert.
Detail The first argument to Insert here is the index we received from IndexOf.
And The index is the position of the start of the substring "cat" in the original string.
Module Module1
Sub Main()
Dim value As String = "the soft cat"
Console.WriteLine("INITIAL: {0}", value)
' Use Insert with IndexOf.
Dim index As Integer = value.IndexOf("cat")
Dim result As String = value.Insert(index, "orange ")
Console.WriteLine("INSERT: {0}", result)
End Sub
End ModuleINITIAL: the soft cat
INSERT: the soft orange cat
A summary. Strings are immutable. When we call Insert we must assign a variable reference to its result. Despite this possible complication, the Insert function is useful in many programs.
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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.
