list0907.cpp

teach yourself C++ in 21 days 第五版

//Listing 9.7 Demonstrates passing by reference
// using references!
#include <iostream>
  
using namespace std;
void swap(int &x, int &y);
  
int main()
{
    int x = 5, y = 10;
 
    cout << "Main. Before swap, x: " << x << " y: " 
       << y << endl;
  
    swap(x,y);
  
    cout << "Main. After swap, x: " << x << " y: " 
       << y << endl;
 
    return 0;
}
  
void swap (int &rx, int &ry)
{
    int temp;
  
    cout << "Swap. Before swap, rx: " << rx << " ry: " 
       << ry << endl;
 
    temp = rx;
    rx = ry;
    ry = temp;
  
  
    cout << "Swap. After swap, rx: " << rx << " ry: " 
       << ry << endl;
  
}