Question

In this article by Sam Saffron, he mentions that Stack Overflow has a route that looks like this:

questions/{id}/{title?} 

Is that a typo? What does that question mark do?

Answer 1

From http://maproutes.codeplex.com/:

[Url("store/{category?}")]
public ActionResult Products(string category)
{
    return View();
}

‘?’ sign at the end of {category?} parameter means that it’s
optional. UrlParameter.Optional will be a default value for it.