How can you change a variable inside a method and also change it outside

Question

I have a variable that I want to change inside a function and reflex the new change in the orginal variable . I am trying to change the original variable value to Scott inside t

Answer 1

You can do that by passing the string by reference -

public ActionResult HomePage()
{
    string name = "John";
    ChangeName(ref name);
    string newName = name ; -- This is now Scott.
}

public static void ChangeName(ref string myname)
{
  myname = "Scott";
}

However, as stated by TheSoftwareJedi in the comments, it is usually best to avoid passing parameters by reference. Instead, you should have your method return the new string, especially considering the fact that strings are immutable, so you can't really change them, you can only change the reference to point to another string.

So a better method would be something like this:

public static string GetAnotherName()
{
  return "Scott";
}

A little more in depth - there are basically two kinds of types in c# (relevant to this point, at least): There are value types like enums, structs (including all primitive types such as int, bool etc') and there are reference types (basically, everything else).

Whenever you pass an argument to a method, it gets passed by value, unless you specify the ref (or out) keyword, even if it's a reference type (in that case, the reference gets passed by value). This means that when ever you are assigning a new value to the argument inside the method, you will only see it outside the method if the argument was passed explicitly by reference (using the ref or out keyword).

The main difference between reference types and value types is that when you change the properties of a reference type inside a method, you will see the new values outside the method as well, however when you change the properties of a value type inside a method, that change will not reflect to the variable outside that method.

Jon Skeet have written a fairly extensive article about that subject, and he is way better than me in explaining things, so you should probably read it as well.