Static Class是引用类型还是值类型？

Question

Whether static class is a reference type or a value type? it would be really helpful if any one gives a good explanation

Answer 1

Class is always a reference type irrespective of whether it is static or non-static.

Answer 2

Value and Reference type is about instances of Types. A static class cannot be instantiated and hence this question is not relevant to static classes.

a static class can only contain static members and static members (like properties) are created once for the entire application, so if you change its value, it changes everywhere in your application.

Answer 3

i think what you are referring to are members of static class.. and they are reference types if they are actually objects otherwise they are simply value types. a static class inself cannot be passed around as for as i know. try running this code

class Program
    {
        static void Main(string[] args)
        {
            StaticClass.x = 89;
            Console.WriteLine(StaticClass.x);
            changeValue(StaticClass.x);
            Console.WriteLine(StaticClass.x);
            Console.ReadKey();
        }
        static void changeValue(int x)
        {
            x = x + 1;
        }
    }
{
    public static class StaticClass
    {
        public static int x { get; set; }
    }
}

EDIT:-
the output is 89 in both the cases
EDIT:-
and still if you dig a little deep a static class is basically a class with a private constructor and no state(Variables) associated with it(unlike the example i have provided). so YES in theory it is a reference type

Answer 4

I just want to add that a Static Class is both a Class and a Type. The static constructor is called one time so it is "created" by the CLR as a Type when first "referenced" in a program, and so is a true class reference type.

But I like to think of the implementation or rather "use" of a Static Class as an empty Type or "class name" only, as that's really how its members are accessed and how it performs. Therefore think of the created Static Class as a hollow pointer to its methods and properties only, not as a pointer to a real instantiated class object that contains those things as a true non-static class would.

Answer 5

Yes, static classes are considered as reference types as when you change a StaticClass.Property value within a method, this change will get populated everywhere you reference this class. It has only one memory address and can't be copied, so that when another method or property call will occur, this new value will prevail over the old one.

Answer 6

Non of them because you cannot copy it as value type and you cannot instantiate it as reference type. This question does not make sense but it does reside on stack like structs, int, double, but it does not allow you to be copied!