Why is implicit typing disallowed in non-local variable declarations?

Question

I changed this:

List<string> chapterNames = new List<string>();

...to this:

var chapterNames = new List<string>();

...and was jabbed with this message from the compiler:

"The contextual keyword 'var' may only appear within a local variable declaration"

Answer 1

The simple answer is because that's how Microsoft introduced the var keyword in the specification for .NET 3.0.

http://msdn.microsoft.com/en-us/library/bb384061.aspx