A copy constructor is a special constructor in the C++ 
programming language used to create a new object as a copy 
of an existing object. 

There are 3 important places where a copy constructor is 
called. 

When an object is created from another object of the same 
type 
When an object is passed by value as a parameter to a 
function 
When an object is returned from a function 


 class B    //With copy constructor
      {
           private:
           char *name;
           public:
           B()
           {
           name = new char[20];
           }
           ~B()
           {
           delete name[];
           }
     //Copy constructor
           B(const B &b)
           {
           name = new char[20];
           strcpy(name, b.name);
           }
      };