What is copy constructor in Oops?

A parameterized constructor that contains a parameter of itself is called as Copy Constructor. The objective of this  constructor is to initialize the new instance with existing one.

Let’s explain this with an example here:

class A
        {
            public string Val;

            public A(string strVal)
            {
                Val = strVal;
            }
            //This is example of copy constructor.
            public A(A objA)
            {
                Val = objA.Val;
            }
        }

        static void Main(string[] args)
        {
            A objA = new A("Oops");
            A objAC = new A(objA);//All objA details will be  copied to objAC
            Console.WriteLine("Value of objAC object == "+ objAC.Val);
            Console.ReadLine();
        }

Output of this program would be
 

This example clearly explains what is the role of copy constructor. It can be very handy in certain situation.