How to: Make an Object Variable Not Refer to Any Instance (Visual Basic)
You can disassociate an object variable from any object instance by setting it to Nothing.
To disassociate an object variable from any object instance
Set the variable to
Nothingin an assignment statement.
' Assume account is a defined class Dim currentAccount As account currentAccount = Nothing
If your code tries to access a member of an object variable that has been set to
Nothing, a NullReferenceException occurs. If you set an object variable to
Nothing frequently, or if it is possible the variable is not initialized, it is a good idea to enclose member accesses in a
.NET Framework Security
If you use an object variable for objects that contain confidential or sensitive data, you can set the variable to
Nothing when you are not actively dealing with one of those objects. This reduces the chance of malicious code gaining access to the data.