Following code throws Process is terminating due to StackOverflowException in the output. Why?

Question

I am new to C#, following is my code, when I run it, it throws Process is terminating due to StackOverflowException in the output.Why??

namespace LearningCSharp
{
    class Program
    {
        //I have created the below object, I have not use it in main() method 
        //  but still because this ouput says StackOverflowException
        Program ProgramObject = new Program();//removing "= new Program() " ,then it works fine

    static void Main(string[] args)
    {
        Program po = new Program();
        po.testing();
    }
    void testing()
    {
        Console.WriteLine("Testing is Ok");
    }
  }
}

Answer 1

You can create it like this:

class Program
{

    static Program programObject = new Program();

    static void Main(string[] args)
    {
        Program po = new Program();
        po.testing();
        Console.ReadLine();
    }

    void testing()
    {
        Console.WriteLine("Testing is working fine!!!");
    }
}

Best regards.