How to calculate the total number of created objects for a particular class in C#/C++?

How do you calculate the total number of created objects for a particular class in C#/C++?

This could be one of the question to in any technical interview. So what is the solution??

suppose think that you have a class abc.

class abc
{
  int x=10;
  Console.WriteLine(a);
}

now if you create the object of the class:
abc a1=new abc();
abc a2=new abc();

now the total number of objects are 2. But how do you calculate it programatically??
Below is the solution:

class mainClass
    {
        static void Main(string[] args)
        {
            abc a1 = new abc();
            abc a2 = new abc();
            abc a3 = new abc();
            abc a4 = new abc();
            abc a5 = new abc();
            abc a6 = new abc();
            Console.WriteLine(abc.count);

        }
    }
    class abc
    {
        public static int count = 0;
        public abc()
        {
            count++;
        }
    }
Output:
6

Hope it helped you :)