What does object @object mean

Question

I've been playing around with events and delegates and need to raise my event asynchronously, thus I've been using:

public event EventHandler OnHelloEvent;

public void Raise()
{
    IAsyncResult syncResult = OnHelloEvent.BeginInvoke(this, new EventArgs(), null, null)

In Intellisense, the last null is stated to be object @object. I haven't come across this before and can't seem to find any documentation for it.

What does this mean? Is it useful?

Answer 1

Everyone answered "What does this mean?" but nobody answered "Is it useful?"

In most cases, the answer is No. You should not use this.

There are a few special exceptions. Off the top of my head:

1. Interoperability issues with someone else's code: Someone else's code requires you to have a variable with a name of a reserved word. Maybe their code was written in a language with different reserved words than C#.
2. Computer-generated code: It doesn't hurt to use an @ symbol. If you're paranoid about reserved word collisions, you might decide that all variables in your computer-generated code will use an @ symbol. Or maybe you are allowing a non-C# program to generate C# programs via a scripting language or whatever and you want to support variables named class.

Answer 2

The @ sign can be thought of as "escape" character of sorts. Since object is a keyword in C#, you cannot use it as a variable name. However prefix it with an @ character and it no longer is a keyword, just a valid variable name!