Question

class Program
    {
        static void Main()
        {           
            Console.WriteLine("enter main method");
            Console.WriteLine(Foo.X);
            Console.ReadKey();
        }
    }
    class Foo
    {
        public static Foo Instance = new Foo();
        public static int X = 3;
        //static Foo()
        //{
        //    Console.WriteLine("static constructor");
        //    Console.WriteLine(X);
        //}
        Foo()
        {
            Console.WriteLine("instance constructor");
        }
    }

Why the program begin with the code in Foo, after that, the main method begin execute.

The result is:

instance constructor
enter main method
3

Anyone can help?

Answer 1

Foo has a static variable called Instance.

This static variable is intialized before Main is executed, which causes the constructor Foo() to be called