CBSE Class 12 Computer Science Constructors And Destructors Concepts

CONSTRUCTORS

CONSTRUCTORS :

A member function with the same as its class is called Constructor and it is used to initialize the object of that class with a legal initial value.

Example :

     class Student

       {

           int rollno;

           float marks;

           public:

           student( ) //Constructor

           {

              rollno=0;

              marks=0.0;

           }

           //other public members

        };

TYPES OF CONSRUCTORS:

1. Default Constructor: A constructor that accepts no parameter is called the Default Constructor. If you don't declare a constructor or a destructor, the compiler makes one for you. The default constructor and destructor take no arguments and do nothing.

2. Parameterized Constructors: A constructor that accepts parameters for its invocation is known as parameterized Constructors , also called as Regular Constructors.

Copy Constructor

• 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.

• A copy constructor is a constructor of the form classname(classname &).The compiler will use the copy constructors whenever you initialize an instance using values of another instance of the same type.

• Copying of objects is achieved by the use of a copy constructor and a assignment operator.

Example :

           class Sample{ int i, j;}

           public:

           Sample(int a, int b) // constructor

           { i=a;j=b;}

           Sample (Sample & s) //copy constructor

            { j=s.j ; i=s.j;

            Cout <<”\n Copy constructor working \n”;

            }

             void print (void)

            {cout <<i<< j<< ”\n”;}

             :

           };

Please refer to attached file for CBSE Class 12 Computer Science Constructors And Destructors Concepts