How much is the actual memory / performance gain in an ASP.NET MVC controller when using these two different ways of declaring the Model for a view?
User user = userService.GetByID(id);
return View(user);
or
return View(userService.GetById(id));
I'm supposing that the last one is a bit more performant as we do not initialize an object, however the first one is more readable. Would this even matter on a webserver with thousands of visitors?
There is zero difference between the two statements as far as what memory is allocated, and the behavior of the garbage collector. Use the one you prefer to read :-)
Actually, you initialize an object in both cases; what the first is doing that the second is not is: 1) reserve some space for a variable (which doesn't concern performance, but space); 2) add a reference to the object (that is, increment the number of references for that object) and then remove the reference (decrement the number of references) the row after.
I would hardly believe that a performance difference is observable between the two.
That said, I prefer the second, as there's no need for the user variable, there; anyway, it's just a matter of taste, there may be styling reasons to prefer the first and other ones to prefer the second.