Why can't we declare var a = new List <string> at the class level?

Question

I know that we cannot do this at the class level, but at the method level we can always do this.

var myList=new List<string> // or something else like this

This question came to my mind as we declare a variable like this. We always provide type information in RHS expressions. Therefore, the compiler does not need to do type guessing. (correct me if I am wrong).

therefore, the question remains WHY NOT at the class level until it is resolved at the method level

Answer 1

. , (, , , , ) .

: var ?

Answer 2

- .

, - IL, " ", , .

.

, , - - , - , , .

Answer 3

var . , , , .

var myList=new List<string>

- , var, .

Answer 4

, var , :

[MyAttribute()] protected internal readonly var list = new List<T>();

, , const!

public const notFoundStatus = 404; // int

Answer 5

Generic referral list type

class Class1
{
    public void genmethod<T>(T i,int Count)
    {


        List<string> list = i as List<string>;

        for (int j = 0; j < Count; j++)
        {
            Console.WriteLine(list[j]);
        }
    }
    static void Main(string[] args)
    {
        Class1 c = new Class1();
        c.genmethod<string>("str",0);
        List<string> l = new List<string>();
        l.Add("a");
        l.Add("b");
        l.Add("c");
        l.Add("d");
        c.genmethod<List<string>>(l,l.Count);

        Console.WriteLine("abc");
        Console.ReadLine();
    }
}