Assign and check for a null value at the same time?
A variable assignment also returns the value. So the syntax in the form of the following will do:
SomeType someVariable;
if ((someVariable = valueToAssign) != null)
{
// valueToAssign was not null
}
In your case:
XElement children;
if ((children = xml.Descendants(ns + "Children").FirstOrDefault()) != null)
{
}
I would do it this way:
XElement children = xml.Descendants(ns + "Children").FirstOrDefault();
if(children != null)
{
//use children
}
You could just do
XElement children = xml.Descendants(ns + "Children").FirstOrDefault();
and then check for null
if (children != null) {...}