Reference Variables

#include <iostream>

using namespace std;

int main()

{

    int x;

    x=10;

    cout<<x<<endl;

    int &r=x;         //r is a reference to x (pointer ==> int *p; p = &x;)

    r=20;             //same as x=20;

    cout<<x<<endl;

    x++;             //same as r++;

    cout<<r<<endl;

    return 0;

}

#include <iostream>

using namespace std;

int main()

{

    int x,y;

    x=10;

    int & iRef=x;

    y=iRef;               //same as y=x;

    cout<<y<<endl;

    y++;                       //x and iRef unchanged

    cout<<x<<endl<<iRef<<endl<<y<<endl;

    return 0;

}

//call by value

#include <iostream>

using namespace std;

void swap(int x, int y);

int main()

{

    int a,b;

    a=10;

    b=20;

    cout<<"before swap: a="<<a<<" b="<<b<<endl;

    swap(a,b);

    cout<<"after swap: a="<<a<<" b="<<b<<endl;

    return 0;

}

void swap(int x, int y)

{

    int t;

    t=x;

    x=y;

    y=t;

}

//call by reference - using pointer

#include <iostream>

using namespace std;

void swap(int *x, int *y);

int main()

{

    int a,b;

    a=10;

    b=20;

    cout<<"before swap: a="<<a<<" b="<<b<<endl;

    swap(&a,&b);

    cout<<"after swap: a="<<a<<" b="<<b<<endl;

    return 0;

}

void swap(int *x, int *y)

{

    int t;

    t=*x;

    *x=*y;

    *y=t;

}

//call by reference - using Reference variables

#include <iostream>

using namespace std;

void swap(int &x, int &y);

int main()

{

    int a,b;

    a=10;

    b=20;

    cout<<"before swap: a="<<a<<" b="<<b<<endl;

    swap(a,b);

    cout<<"after swap: a="<<a<<" b="<<b<<endl;

    return 0;

}

void swap(int &x, int &y)

{

    int t;

    t=x;

    x=y;

    y=t;

}