AddressOf, an operator, enables delegate Functions. With it we reference a method and use it as the implementation for a delegate. We use the name of a function and specify it where a delegate is required.
Example. First, this program introduces the IsThreeLetters Function, which receives a String and returns a Boolean. This Function is used as a delegate. The Main entry point creates a List and adds 3 values to it.
Then The List.Find Function is used to find the first 3-letter String in the List instance.
AddressOf The AddressOf operator is used and it references the IsThreeLetters Function. We display the result.
Discussion. In the C# language, you do not need AddressOf. Instead, you can use the method name directly as the delegate. The AddressOf operator may be less confusing. It introduces the context in which the method name should be referenced.
And It tells you that the method name is just used to acquire a memory address.
VB.NET program that uses AddressOf
Function IsThreeLetters(ByVal value As String) As Boolean
Return value.Length = 3
Dim list As List(Of String) = New List(Of String)
Dim value As String = list.Find(AddressOf IsThreeLetters)
Summary. The AddressOf operator provides an excellent way for you to reference an existing Function and turn it into a delegate. This means you do not need to use lambda expression syntax. You can use existing functions.