A copy constructor is a constructor that creates a new object that is a clone of an existing object. The term is mostly used in the C++ programming language, where copy constructors have a special status.
A copy constructor is a special constructor in the C++ programming language for creating a new object as a copy of an existing object. The first argument of such a constructor is a reference to an object of the same type as is being constructed (const or non-const), which might be followed by parameters of any type (all having default values).
Normally the compiler automatically creates a copy constructor for each class (known as a default copy constructor) but for special cases the programmer creates the copy constructor, known as a user-defined copy constructor. In such cases, the compiler does not create one. Hence, there is always one copy constructor that is either defined by the user or by the system.
