static void Main(string[] args)
{
// Animal animal = new Animal(); // error because of abstract class
IInterface obj = new MyClass2();
obj.Hi();
Cat cat = new Cat();
Animal cat1 = new Cat();
cat.Sound();
cat1.Sound();
cat.VSound();
cat1.VSound();
/*
*
* int a = null; // error
*
* int? na = null; // same as the below
* //Nullable<int> na = null;
*
*/
/*
*
* // ?? --> if(null)
* // ? --> if(!null)
* //
* // kiminiden dusunule biler
*
*
* MyClass my = null;
*
* my?.Hi("Resad"); // same as the below
*
* //if (my != null)
* // my.Hi("Resad");
*
*
* ///
*
* string str = null;
* string str1 = "";
*
* str = str ?? "Anotherthing";
* str ??= "Anotherthing"; // same as the above
*
* //
*
* str1 = str ?? "Something"; // same as the below
*
* if (str == null) str1 = "Something";
* else str1 = str;
*
* Console.WriteLine(str1);
*
*/
}