看如下代码： 

#include<iostream>
using namespace std;#include<string>//结构体
struct Student {string name;int age;int score;}st3;//值传递
void printStufdents(struct Student st2) {cout << "子函数" << endl;st2.age = 150;cout << "名字：" << st2.name << "	年龄：" << st2.age << "	分数：" << st2.score << endl;
}//指针传递只占四个字节  节省内存空间  而且不会复制新的副本出来
void printStufdents(struct Student *s) {cout << "子函数" << endl;s->age = 150;cout << "名字：" << s->name << "	年龄：" << s->age << "	分数：" << s->score << endl;
}int main() {struct Student st2 = { "张三丰",120,70 };cout << "名字" << st2.name << "年龄" << st2.age << "分数" << st2.score<< endl;printStufdents(st2);system("pause");
}

1，地址传递只占四个字节  节省内存空间  而且不会复制新的副本出来

2，地址传递有个问题，会改变地址的值，为了防止误操作，我们引入了const关键字修饰指针

#include<iostream>
using namespace std;#include<string>//结构体
struct Student {string name;int age;int score;
}st3;void printStufdents(struct Student st2) {cout << "子函数" << endl;st2.age = 150;cout << "名字：" << st2.name << "	年龄：" << st2.age << "	分数：" << st2.score << endl;
}//指针传递只占四个字节  节省内存空间  而且不会复制新的副本出来
void printStufdents(const struct Student *s) {cout << "子函数" << endl;s->age = 150;cout << "名字：" << s->name << "	年龄：" << s->age << "	分数：" << s->score << endl;
}int main() {struct Student st2 = { "张三丰",120,70 };cout << "名字" << st2.name << "年龄" << st2.age << "分数" << st2.score<< endl;printStufdents(st2);system("pause");
}