Confusion of access level of variables in static method.

Ashwani Chaudhary

using System;

namespace ConsoleApplication19
{
    class Program
    {
         int a = 10;
       static int b = 10;

        static void myfun()
        {
              int j = 10;

             Console.WriteLine("Hello {0}",j); // valid
             Console.WriteLine("Hello {0}", a); //invalid
             Console.WriteLine("Hello {0}", b); //valid
       }

     static void Main(string[] args)
     {
            myfun();
          Console.ReadKey();
    }
}
}

18 Replies

Know the answer? Post it — somebody with the same question will find it here.

Guest User11y ago
Accepted answer
Before obj2 = obj; they have their own memory space.

After obj2 = obj; they both point to the same memory space.
Ashwani Chaudhary11y ago
Here obj and obj2 have same memory location (i mean pointing to same memory location) or obj2 have its own memory location other then obj and have memory address in obj2 memory location
Guest User11y ago
Initially yes.

Program obj = new Program();
Program obj2 = new Program(); // here you create a new instance, different from obj

obj.name = "ashu";

obj2 = obj; // here you tell obj2 to point to obj, thus removing it's original different values
Ashwani Chaudhary11y ago
If i allocate a new instance with obj2 then its having same problem . is it still point to same object reference .even i have give a different memory and instance to obj2

class Program
{
string name = string.Empty;

static void Main(string[] args)
{
Program obj = new Program();
Program obj2 = new Program();
obj.name = "ashu";
obj2 = obj;
Console.WriteLine(obj2.name);
Console.ReadKey();

}
}
Guest User11y ago
With obj2 = obj1 you make a reference to obj1. You now have two variables pointing to the same class instance. Changes to one are visible in both.
Ashwani Chaudhary11y ago
pritaeas

I have a question please give me conclusion of this .

class Program
{
string name = string.Empty;

static void Main(string[] args)
{
Program obj = new Program();
Program obj2 =Program();
obj.name = "ashu";
obj2 = obj;
Console.WriteLine(obj2.name);
Console.ReadKey();

}
}

Why obj2 hold name "ashu" here ....what is the concept
Ashwani Chaudhary11y ago
Pritaeas Thanks
Now i got the concept
Guest User11y ago
The local variable gets its memory when the method is initialized, each time you call it. So it is NOT initialized with the static variable.
Ashwani Chaudhary11y ago
As per the definition of c# only static data members get memory when a class loads so a local variable also get initialize with static member get initialize ?

As well i heard only static member get memory when a class load so why a local variable get memory without class object initialization. Then what is the difference and benefit of initialization of static variables
Guest User11y ago
Yes. There is also const and readonly of course. const is accessible by static and instance methods alike. readonly differs between non-static and static like a regular variable.
Ashwani Chaudhary11y ago
Ok fine and thanks for explanation sir. So as per the information you have given to me .There are three type of variable scope

1 ) Local Variable
2) Static variable
3) Instance variable

am i right sir ....
Guest User11y ago
That one is a local variable (not an instance variable), it is recreated every time the method is called.
Ashwani Chaudhary11y ago
But in myfun() static method there is an instance variable int J which is not static but working fine ....so from where and when get memory because as we know it is instance variable and instance variable always get memory at the time of initialize an object of class
Guest User11y ago
They get initialized when an object is instantiated with new. These variables are not accessible in a static method.
Ashwani Chaudhary11y ago
But my question is if a Static function can accept static class variable only because static variable gets memory at program execution start but non static variable in static function ...how does they get memory and valid inside static function
Raja T11y ago
Hi,A field declared with the static modifier is called a static variable.static variable shared the value of it among all instances of the class.

int a =10 and static int b=10;
It is outside of the myfun()
and int j=10 is inside of the function

So here j is valid ,b is valid why means b is static variable means you can access any where of the this class means(inside the funtion,outside the function) and finaly a is invalid why means by default acess specifier is private it can not access outside of the class.

Please check out more details of static variable
https://msdn.microsoft.com/en-us/library/aa691162(v=vs.71).aspx
http://stackoverflow.com/questions/10795502/what-is-the-use-of-static-variable-in-cwhen-to-use-itwhy-cant-i-declare-the-s
Manas Mohapatra11y ago
Hi,
Let's discuss why it is not accessible:

When you declare -> int a = 10;
By default access specifier is private. Secondly if you want access the value then access like:
Console.WriteLine("Hello {0}", new Program().b);

Secondly you are trying to access the variable(b) inside static method so it needs a static variable or instance of a object. If you check same thing by declaring a a normal function(without static) then you can access that variable directly without creating instance.

When you declare static int b = 10;
When you declare a variable as static then you can access this value without creating object.
Because static always stay in memory and it dies when application stops.
Guest User11y ago
A static method can only read static variables from it's class (and constants), but not instance variables. An instance variable (a) is only accessible from an object/class instance, not from the class.