Question

Possible Duplicate:
Using var outside of a method

I’ve searched for this a bit, but am not too sure of the search terms so didn’t find anything.

Why can’t i do this:

class foo
{
    var bar = new Dictionary<string, string>();
}

Guessing there must be a very good reason, but i can’t think of it!

I’m more interested in the reasoning, rather than the because “C# doesn’t let you” answer.

EDIT: Edited Dictionary declaration, sorry (just a typo in the example)!

Answer 1

2 reasons:

1. The Dictionary requires Key and Value generic parameters
2. You cannot write variables like this directly inside a class => you could use fields, properties or methods

So:

class foo
{
    private Dictionary<string, string> bar = new Dictionary<string, string>();
}

As to why you cannot do this:

class foo
{
    private var bar = new Dictionary<string, string>();
}

Eric Lippert has covered it in a blog post.