Problem with passing the value

Hi,
What  understood is that you are asking why ArrayList not null even after made it null in side another function. Actually it's null only, but you are not storing that value and seems like it's not null. Look below code and concentrate on bolded lines where I stored the latest version after nullified. Here I am getting null
 private void Form1_Load(object sender, EventArgs e)
        {
            ArrayList arr = new ArrayList();
            arr.Add(1);

            arr = SomeMethod(arr);
           
        }
        public ArrayList SomeMethod(ArrayList arr)
        {
            arr = null;
            return arr;
        }

Thanks..It helped..
But I just wanted to know why it was behaving like that when not adding ref.. ?

Ya that I know..But my query is why this is behaving like this..?
Why the null value is not reflecting whereas modifications are getting reflected ??

you can use ref keyword to pass by reference .,

This is the scenario..
I have created one arraylist.
ArrayList arr=new ArrayList();
Arr.Add(1);
SomeMethod(Arr);
Public ArrayList SomeMethod(ArrayList Arrs)
{
   Arrs.Add(2);
  return Arrs;
}
In the above case the updated result is getting reflected in the variable Arr in calling method i.e now we are getting two items in Arr.
But if in SomeMethod function we nullify Arrs and return Arrs.its not getting updated with null value in calling function .Still it is having old value..i.e 1.
 
 
 
 
 
 
 
 

are you calling by value or reference? read the content about call by value and call by reference