014_Dec21

December 21

Constructor and Destructor

Construtor and Destructor are special class member function in C++ where, classname and method names are same and for destructors we use the symbol (~) infornt of classname.

Example

class class_name {
    //private data members
    //public data members

    //Constructor 
    class_name(parameter_list(s)) {
        //constructor body
    }
};

1. Example of Constructor

#include <iostream>
using namespace std;

class Student{
    public:
        int roll;

        // declaring constructor
        Student() {
            roll = 12;
        }
};

int main() {
        Student std;

        cout << "The roll number is = " << std.roll;
        
        return 0;
}

2. Demonstrate an example of contructor that can be defined outside the class

#include <iostream>
using namespace std;

class Student{
    public:
        int roll;

        // declaring constructor
        Student();
};

Student::Student() {
        roll = 12;
}

int main() {
        Student std;

        cout << "The roll number is = " << std.roll;

        return 0;
}