2.3.1 引用

练习2.15

int ival = 1.01; //程序可运行，但提示从double转到int，可能会丢失部分数据
int &rvall = 1.01; //错误，引用不能于字面值绑定在一起
int &rval2 = ival; // 合法
int &rval3; //报错，引用必须被初始化，绑定对象

练习2.16

int i = 0, &r1 = i;
double d = 0, &r2 = d;
r2 = 3.14159; // 合法，把3.14159赋给r2指向的对象，此次即是赋给了d
cout << i << endl;
cout << d << endl;

int i = 0, &r1 = i;
double d = 0, &r2 = d;
r2 = r1; //把r1指向的对象，i，赋给了r2指向的对象，d
cout << i << endl;
cout << d << endl;

int i = 0, &r1 = i;
double d = 0, &r2 = d;
i = r2; //把r2指向的对象，d，赋给了i
cout << i << endl;
cout << d << endl;
//提示，从double转到int，可能丢失数据

int i = 0, &r1 = i;
double d = 0, &r2 = d;
r1 = d; //把d，赋给了r1指向的对象，i
cout << i << endl;
cout << d << endl;
//提示，从double转到int，可能丢失数据

#include <iostream>
using namespace std;

int main() {
	int i, & ri = i; //定义变量i，ri指向i
	i = 5; ri = 10; //把10赋值给ri指向的对象，此处即是献给了i
	cout << i << " " << ri << endl; //i和ri的输出结果必然相同
	return 0;
}