Perhaps this is something everyone already knew about, but I recently came across this little C# combo that solves one of my major outstanding issues with the var keyword.
I consider var to actually be quite a useful language feature to reduce repetition and make your code slightly more flexible for refactoring, but I’ve always had one little problem with it.
What if I want a base class type or interface?
I most often run into this problem when I am working with lists.
Have you ever written some code like this?
| var myList = new List<int>(); |
The problem with this code is that we are stuck with the concrete List implementation for our variable myList, because we don’t have a way of specifying that we actually want an IEnumerable to be our reference type.
The solution is so simple that I am a bit surprised I didn’t think of it earlier.
I had always assumed that I just couldn’t use var there and would have to declare the type like so:
| IEnumerable<int> myList = new List<int>(); |
But we can actually just use as to keep our var in place if we want to.
| var myList = new List<int> as IEnumerable<int> |
So it’s actually a little more verbose, but I think it is a bit more clear, and it is more consistent if you are using var everywhere else.
There has to be a better use
I’ve been racking my brain trying to come up with more useful ways to use this little combo, but I can’t really seem to come up with anything.
It seems like there has to be something else you could use this combo for.
What do you think? Any ideas?