tut34.cpp

// Copy Constructor in C++

#include<iostream>
using namespace std;

class Number{
    int a;
    public:
    Number(){
        a = 0;
    }

    Number(int num){
        a = num;
    }

    // When no copy constructor is found , compiler supplies its own copy constructor
    Number(Number &obj){
        cout<<"Copy constructor invoked !!! "<<endl;
        a = obj.a;
    }

    void display(){
        cout<<"The number for this object is "<<a<<endl;
    }

};

int main(){
    Number x,y,z(45),z2;
    x.display();
    y.display();
    z.display();

    Number z1(z); // Copy constructor invoked 
    z1.display();

    z2 = z ; // Copy constructor not called 
    z2.display();

    Number z3 = z; // Copy constructor invoked
    z3.display();

    // z1 should exactly resemble z or x or y. 
    
    return 0;
}