C++ Examples

Write a C++ Program to print a welcome text in a separate line.

Write a program to swap private data members of two classes using friend function.

#include<iostream>
using namespace std;

class a1
{
    private:
    int x,y;
    
    public:
    
    //function to take input from the user
    
    void input()
    {
        cout<<"Enter first number to swap ";
        cin>>x;
        cout<<"Enter second number to swap ";
        cin>>y;
        cout<<"Before swapping numbers are "<<x<<" "<<y<<endl;
    }
    
    //function for swapping of two numbers
    
    friend void swapTwoNumbers(a1 &obj);
    
    //function to display two swapped numbers
    
    void display()
    {
       cout<<"The numbers after swapping are "<<x<<" "<<y; 
    }
    
};

void swapTwoNumbers(a1 &obj)
{
    //Swapping of numbers using inbuilt swap funtion
    
    swap(obj.x,obj.y);
}

int main()
{
    a1 obj1;
    
    obj1.input();
    swapTwoNumbers(obj1);
    obj1.display();
    
    return 0;
}

Output

Enter first number to swap 25
Enter second number to swap 46
Before swapping numbers are 25 46
The numbers after swapping are 46 25

Another method: Without inbuild swap function

#include<iostream>
using namespace std;

class a1
{
    private:
    int x,y,z;
    
    public:
    
    //function to take input from the user
    
    void input()
    {
        cout<<"Enter first number to swap ";
        cin>>x;
        cout<<"Enter second number to swap ";
        cin>>y;
        cout<<"Before swapping numbers are "<<x<<" "<<y<<endl;
    }
    
    //function for swapping of two numbers
    
    friend void swapTwoNumbers(a1 &obj);
    
    //function to display two swapped numbers
    
    void display()
    {
       cout<<"The numbers after swapping are "<<x<<" "<<y; 
    }
    
};

void swapTwoNumbers(a1 &obj)
{
    //Swapping of numbers 
    
    obj.z = obj.x;
    obj.x = obj.y;
    obj.y = obj.z;
}

int main()
{
    a1 obj1;
    
    obj1.input();
    swapTwoNumbers(obj1);
    obj1.display();
    
    return 0;
}

Enter first number to swap 23
Enter second number to swap 45
Before swapping numbers are 23 45
The numbers after swapping are 45 23