Global variables in Visual C#

How do I declare global variables in Visual C#?

From stackoverflow

• How about this

  public static class Globals {
      pulic static int GlobalInt { get; set; }
  }
  

  Just be aware this isn't thread safe. Access like Globals.GlobalInt

  This is probably another discussion, but in general globals aren't really needed in traditional OO development. I would take a step back and look at why you think you need a global variable. There might be a better design.

  Pavel Minaev : In what sense is it not thread safe? And how is that any different from a non-static property?

  0A0D : -1 for not explaining why it isn't thread safe... needs more explanation

  Bob : This isn't a question about thread safety. If you are interested in thread safety then ask in another question or update this question to explicitly include a thread safe solution. Also see this question for what thread safety is if you never heard the term http://stackoverflow.com/questions/261683/what-is-meant-by-thread-safe-code

  Russell : +1 for "I would take a step back and look at why you think you need a global variable. There might be a better design." I found in large projects, it is a lot more difficult to track the use of global variables opposed to instance variables. This helps, especially during maintenance.

• Use the const keyword:

  public const int MAXIMUM_CACHE_SIZE = 100;
  

  Put it in a static class eg

  public class Globals
  {
      public const int MAXIMUM_CACHE_SIZE = 100;
  }
  

  And you have a global variable class :)

  Phenom : Doesn't the const keyword make it constant? Can it be changed?

  mykhaylo : "The const keyword is used to modify a declaration of a field or local variable. It specifies that the value of the field or the local variable cannot be modified." - http://msdn.microsoft.com/en-us/library/e6w8fe1b%28VS.71%29.aspx

  JohannesH : A const field isn't varable. ;)

  Russell : lol yeah - i read the question too quickly, I usually only provide contants when exposing values globally. Everything else are in instance variables. :)

• You can'nt declare global variables - use static class or Singleton pattern

• The nearest you can do this in C# is to declare a public variable in a public static class. But even then, you have to ensure the namespace is imported, and you specify the class name when using it.

• A public static field is probably the closest you will get to a global variable

  public static class Globals
  {
    public static int MyGlobalVar = 42;
  }
  

  However, you should try to avoid using global variables as much as possible as it will complicate your program and make things like automated testing harder to achieve.