Tip:All instances of the first parameter's string data are replaced with the second parameter's string data.
Nothing:You can use an empty string literal or the Nothing literal to indicate an empty string.
Here:In this example, we replace the first word parameter with the second word parameter.
Based on: .NET 4.5 VB.NET program that uses Replace Module Module1 Sub Main() ' Assign string to literal. Dim value1 As String = "XXpagitica" Console.WriteLine(value1) ' Replace substring with another substring. Dim value2 As String = value1.Replace("XX", "Areo") Console.WriteLine(value2) End Sub End Module Output XXpagitica Areopagitica
Tip:This behavior is useful when dealing with common string replacements in programs.
But:If you do not understand this behavior you may end up writing inefficient code that has unneeded loops.
Here:The string containing the characters "Net" is replaced with the characters "Bottle". These substrings are case-sensitive.
VB.NET program that uses Replace on instances Module Module1 Sub Main() ' Assign string to literal constant. Dim value1 As String = "Dot Net Perls is about Dot Net." Console.WriteLine(value1) ' Replace every instance of the string. Dim value2 As String = value1.Replace("Net", "Bottle") Console.WriteLine(value2) End Sub End Module Output Dot Net Perls is about Dot Net. Dot Bottle Perls is about Dot Bottle.
However:The StringBuilder class implements optimizations that can improve memory usage and speed when doing many replacements.
VB.NET program that uses StringBuilder Replace Imports System.Text Module Module1 Sub Main() ' Create new StringBuilder and initialize it. Dim builder As New StringBuilder("This is an example.") Console.WriteLine(builder) ' Replace string in StringBuilder. builder.Replace("This", "Here") Console.WriteLine(builder) ' Insert into StringBuilder. builder.Insert(0, "Sentence: ") Console.WriteLine(builder) End Sub End Module Output This is an example. Here is an example. Sentence: Here is an example.
Tip:If you have many replacements to perform, using StringBuilder will likely perform better.
Tip:Often we can convert a string into a StringBuilder, and then use the Replace, Append and Insert methods on that StringBuilder.
Then:We can convert the StringBuilder back into a string with the ToString method.
Tip:Regular expressions allow you to do much more complex replacements with less code.
However:Simple replacements are faster to do in the String or StringBuilder classes. The regular expression parser has overhead.