C++构造函数实例——拷贝构造，赋值

#define _CRT_SECURE_NO_WARNINGS //windows系统 
#include <iostream> 
#include <cstdlib> 
#include <cstring>
using namespace std;

class student 
{
private:
    char *name;
    int age;
public:
    student(const char *n = "no name", int a = 0) 　　
    {
        name = new char[100];                 // 比malloc好!         
        strcpy(name, n);
        age = a;
        cout << "构造函数，申请了100个char元素的动态空间" << endl;
    }
    student & operator=(const student &s) 
    {    
        strcpy(name, s.name);
        age = s.age;
        cout << "赋值函数，保证name指向的是自己单独的内存块" << endl;
        return *this;    //返回 “自引用”     
    }    
    student(const student &s) 
    {               // 拷贝构造函数 Copy constructor     
        name = new char[100];
        strcpy(name, s.name);
        age = s.age;
        cout << "拷贝构造函数，保证name指向的是自己单独的内存块" << endl;
    }
    void display(void)
    {
        cout << name << ", age " << age << endl;
    }
　　virtual ~student() 
    {                             // 析构函数     
        cout << "析构函数，释放了100个char元素的动态空间" << endl;
        delete[] name;                          // 不能用free!         
    }
};
int main() 
{
    //student s;    //编译错误，类中实现了构造函数，因此，需要有参数
    student k("John", 56);
    student mm(k);        //拷贝构造函数
    
    student m("lill", 666);
    m.display();

    m = k;                //赋值函数
    k.display();
    mm.display();

    return 0;
}