Light at the end of null

by Vitor Fernandes — on  , 

One of the coolest things in the new C# 6.0 is the Null-Conditional operator. It provides a way to largely simplify and avoid one of the most common things in c#: protecting against null.

So, instead of doing this:

var a = null;
if (b != null)
{
    a = b.SomeValue;
}

you can now just do:

var a = b?.someValue;

You can even chain several calls and it works using a short-circuit logic, same as with logical operators. It will evalute the expression from left to right. If any part of it returns null, the whole expression will return null.

Suppose you need to parse some XML:

XDocument doc = XDocument.Load("test.xml");
var field = doc.Descendants("field")
               .Where(x => (string) x.Attribute("name") == "my_cool_id")
               .FirstOrDefault();

if (field != null)
{
    string value = (string) field.Element("value");
    // Use value here
}

Using the new Null-Conditional operator, it would look like:

XDocument doc = XDocument.Load("test.xml");
string value = doc.Descendants("field")
               .Where(x => (string) x.Attribute("name") == "my_cool_id")
               .FirstOrDefault()?.Element("value")?.ToString();

// Use value here

Pretty cool, huh?

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