To make the workflow logic easy to understand, translate the workflow into C# code. It will look like:

int NumberCounter = 0;
do 
{
    Console.WriteLine(NumberCounter);
    NumberCounter++;
}while (NumberCounter <= 5);

While we can use arguments to flow data into and out of a workflow, we use Variable to store data in a workflow. Every variable has its scope, and can be accessed by activities within its scope. Variable in WF4 is pretty much like variables in imperative language such as C#.

Please note that we cannot access to the workflow variables from the outside host. WF4 variables are designed for sharing data inside the workflow instance. We can use Bookmark to access the workflow from the outside host.