引用作函数参数不需要初始化

#include <iostream>using namespace std;void swap(int a ,int b){int c=0;c = a;a = b;b = c;}void swap1(int*a ,int*b){int c=0;c = *a;*a = *b;*b = c;}//引用作函数参数不需要初始化void swap2(int &a ,int &b){int c=0;c = a;a = b;b = c;}int main(){int x =10;int y =20;swap(x,y);printf("x=%d,y=%d\n",x,y);swap1(&x,&y);printf("x=%d,y=%d\n",x,y);//a就是x的别名，b就是y的别名，对a修改就是对x修改swap2(x,y);printf("x=%d,y=%d\n",x,y);system("pause");return 0;}