#include <iostream>
using namespace std;

/**
 * Swap two integer values passed in by value.
 * @param a the first value.
 * @param b the second value.
 */
void swap_by_value(int a, int b);

/**
 * Swap two integer values passed in by reference.
 * @param a the first value.
 * @param b the second value.
 */
void swap_by_reference(int& a, int& b);

int main()
{
    int i = 1, j = 5;

    cout << "Before swap_by_value: i = " << i << ", j = " << j << endl;
    swap_by_value(i, j);
    cout << " After swap_by_value: i = " << i << ", j = " << j << endl;
    cout << endl;
    cout << "Before swap_by_reference: i = " << i << ", j = " << j << endl;
    swap_by_reference(i, j);
    cout << " After swap_by_reference: i = " << i << ", j = " << j << endl;

}

void swap_by_value(int a, int b)
{
    int temp = a;
    a = b;
    b = temp;
}

void swap_by_reference(int& a, int& b)
{
    int temp = a;
    a = b;
    b = temp;
}