Example of copy constructor
Example:1
Write a C++ program to declare a class named student with attributes as roll, name, and per, further take input for details and display them?
Sol:
#include <iostream>
#include<string.h>
using namespace std;
class student
{
private:
int roll;
char name[20];
float per;
public:
student(); //default constructor
student(int r,char *n,float p); //Parameterized constructor
student(student &s); //copy constructor
void read();
void show();
};
//default constructor
student::student()
{
roll=0;
name[0]='\0';
per=0;
}
//Parameterized constructor
student::student(int r,char *n,float p)
{
roll=r;
strcpy(name,n);//strcpy() : header file : string.h
per=p;
}
//copy constructor
student::student(student &s)
{
roll=s.roll;
strcpy(name,s.name);
per=s.per;
}
void student::read()
{
cout<<"Enter roll,name and per ";
cin>>roll>>name>>per;
}
void student::show()
{
cout<<"roll "<<roll<<" name "<<name<<" per "<<per<<endl;
}
int main()
{
student s1,s2(1001,"Kapil",94);
s1.show();
s2.show();
student s3(s2);
s3.show();
return 0;
}
/* Output */ roll 0 name per 0 roll 1001 name Kapil per 94 roll 1001 name Kapil per 94
Example:2
Write a C++ program to declare a class named employee with attributes as empno, name and salary, further take input for details and display them?
Sol:
#include <iostream>
#include<string.h>
using namespace std;
class employee
{
private:
int empno;
char name[20];
float sal;
public:
employee(); //default constructor
employee(int a,char *n,float s); //Parameterized constructor
employee(employee &e); //copy constructor
void read();
void show();
};
//default constructor
employee::employee()
{
empno=0;
name[0]='\0';
sal=0;
}
//Parameterized constructor
employee::employee(int a,char *n,float b)
{
empno=a;
strcpy(name,n);//strcpy() : header file : string.h
sal=b;
}
//copy constructor
employee::employee(employee &e)
{
empno=e.empno;
strcpy(name,e.name);
sal=e.sal;
}
void employee::read()
{
cout<<"Enter empno,name and sal ";
cin>>empno>>name>>sal;
}
void employee::show()
{
cout<<"empno "<<empno<<" name "<<name<<" sal "<<sal<<endl;
}
int main()
{
employee e1,e2(1001,"Kapil",45000);
e1.show();
e2.show();
employee e3(e2);
e3.show();
return 0;
}
/* Output */ empno 0 name sal 0 empno 1001 name Kapil sal 45000 empno 1001 name Kapil sal 45000
