Why in a web application, on a page, 8 is displayed, and not 4?

Question

ASP.NET

The code for the Configure method of the Startup class:

public void Configure(IApplicationBuilder app)
    {
      int x = 2;
      app.Run(async (context) =>
      {
        x = x * 2;  //  2 * 2 = 4
        await context.Response.WriteAsync($"Result: {x}");
      });
    }

In theory, we expect 4, but the page displays 8: https://metanit.com/sharp/aspnet5/pics/middlewarel...
Why? Is it related to async? Or with how many requests the browser sends?

Answer 1

This is because the anonymous method is called twice. Once for logs, the second for sending to the client. Don't write anything to parent method variables.