Javascript's void in C#?

Is there something like Javascript's void operator in C#?

Javascript's void, "evaluates an expression and discards the result, returning undefined". Thus, I'm looking for something built-in that "evaluates" and returns null, or maybe the type default. (So it should sort of be like the inverse of the null-coalescing ?? operator.)

Example use:

Person a;

public void main() {
    var x = void(a = new Person());
    // x should contain null
}

class Person { }

(Example does not compile due to illegitimate use of keyword "void", naturally.)

I currently use this—which works—but feels crufty:

protected object voided(object ob) {
    return null;
}

Edit. Ok, so I definitely need to add some more details. I'm using the code in an inline DataBind expression in ASP.NET code. E.g.:

<开发者_如何学Go;asp:Repeater runat="server">
   <ItemTemplate>
       </tr><%# voided(globalPersonVariable = (Person)Container.DataItem)) %></tr>
   </ItemTemplate>
</asp:Repeater>

Using default, unfortunately does not work here.

(I didn't include this additional information the first time, because I wanted to keep it a "pure" C#-question, not ASP.NET.)

Something like this you're looking for?

var x = default(Person) // null
var i = default(int) // 0

You could just make an extension method, Voided()

public static object Voided<TType>(this TType tThis)
{
    return null;
}

Then you can call it like so:

(globalPersonVariable = (Person)Container.DataItem)).Voided()

If you want to combine this with the default stuff other people have mentioned, it would change to:

public static TType Voided<TType>(this TType tThis)
{
    return default(TType);
}

Not sure what void function does in javascript, but to get a default value of a type, use default keyword:

protected T voided<T>(T obj) {
    return default(T);
}

You could use the default keyword:

http://msdn.microsoft.com/en-us/library/xwth0h0d(v=vs.80).aspx

I just want to throw these two snippets into the mix. Both work, but they still feel more verbose than necessary.

(globalPersonVariable = (Person)(Container.DataItem)) == null ? null : null

((Func<object,object>)(x => null))(globalPersonVariable = (Person)(Container.DataItem))

For databinding purposes, you can also emit the empty string:

(globalPersonVariable = (Person)(Container.DataItem)) == null ? "" : ""

The distinction might seem trivial, but this can save you from needing to cast the nulls in certain situations.