//Requires: nothing
//Modifies: x and y
//Effects: will swap the values of x and y
//         if x = 7 and y = 13 upon entry
//         when this function ends, x = 13 and y = 7
void swap(int & x, int & y)
{
    int temp;
    temp = x; //Assigns x to the new declared int
    x = y; //Makes x = y
    y = temp; //Assigns y to temp, swapping it
}


Then I try to do:

int main()
{
int a = 13;
    int b = 7;
    int c = 50;
    int d = 5;
    int e = 33;
    int f = 28;
    swap(a, b);
    swap(c, d);
    swap(e, f);
return 0;
}