C ++ as the reference parameter
We have already discussed how to use pointers, to refer to the calling function. The following example uses a reference to a reference to the calling function to achieve.
#include <iostream> using namespace std; // 函数声明 void swap(int& x, int& y); int main () { // 局部变量声明 int a = 100; int b = 200; cout << "交换前,a 的值:" << a << endl; cout << "交换前,b 的值:" << b << endl; /* 调用函数来交换值 */ swap(a, b); cout << "交换后,a 的值:" << a << endl; cout << "交换前,b 的值:" << b << endl; return 0; } // 函数定义 void swap(int& x, int& y) { int temp; temp = x; /* 保存地址 x 的值 */ x = y; /* 把 y 赋值给 x */ y = temp; /* 把 x 赋值给 y */ return; }
When the above code is compiled and executed, it produces the following results:
交换前,a 的值: 100 交换前,b 的值: 200 交换后,a 的值: 200 交换后,b 的值: 100