what is copy constructor in c++ - Wikitechy https://www.wikitechy.com/interview-questions/tag/what-is-copy-constructor-in-c/ Interview Questions Thu, 18 Aug 2022 10:41:50 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 https://www.wikitechy.com/interview-questions/wp-content/uploads/2025/10/cropped-wikitechy-icon-32x32.png what is copy constructor in c++ - Wikitechy https://www.wikitechy.com/interview-questions/tag/what-is-copy-constructor-in-c/ 32 32 What is Constructor in C++ ? https://www.wikitechy.com/interview-questions/cpp/what-is-constructor-in-cpp/ https://www.wikitechy.com/interview-questions/cpp/what-is-constructor-in-cpp/#respond Thu, 18 Aug 2022 10:41:19 +0000 https://www.wikitechy.com/interview-questions/?p=4768
  • In C++ constructor is a special type of member function of a class which initializes objects of a class.
  • Constructor is automatically called when object is created in C++.
  • It does not have any return type because it is special member function of the class.
  • In public section of class and it has same name as the class itself.
  • Copy and parameterized constructors have input arguments, by default constructors don’t have input argument however.
  • C++ compiler generates a default constructor for object, if we do not specify a constructor.
  • In constructor there are three types, they are default constructor, parameterized constructor, copy constructor.

    • Default Constructor

    • It is the constructor which has no parameters and doesn’t take any argument.

    Sample Code

    using namespace std;

    class construct

    {

    public:

        int a, b;




        // Default Constructor

        construct()

        {

            a = 30;

            b = 40;

        }

    };




    int main()

    {

        // Default constructor called automatically

        // when the object is created

        construct c;

        cout << "a: " << c.a << endl

             << "b: " << c.b;

        return 1;

    }

    Output

    Parameterized Constructor

    • It is possible to pass arguments to constructors and these arguments help initialize an object when it is created typically.

    Sample Code

    using namespace std;

    class Point

    {

    private:

        int x, y;




    public:

        // Parameterized Constructor

        Point(int x1, int y1)

        {

            x = x1;

            y = y1;

        }




        int getX()

        {

            return x;

        }

        int getY()

        {

            return y;

        }

    };




    int main()

    {

        // Constructor called

        Point p1(10, 15);




        // Access values assigned by constructor

        cout << "p1.x = " << p1.getX() << ", p1.y = " << p1.getY();




        return 0;

    }

     Output

    Copy Constructor

    • It is a member function which initializes an object using another object of the same class.

    Sample Code

    using namespace std;

    class point

    {

    private:

      double x, y;




    public:

       

      // Non-default Constructor &

      // default Constructor

      point (double px, double py)

      {

        x = px, y = py;

      }

    };




    int main(void)

    {




      // Define an array of size

      // 10 & of type point

      // This line will cause error

      point a[10];




      // Remove above line and program

      // will compile without error

      point b = point(5, 6);

    }

    Output

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