[C++知识库]C++类的基础知识

构造与析构

#include <iostream>
#include <string>
#include "stdio.h"
#include "string.h"

class stu {
public:
    stu(std::string Name, int Age, char * Stu_ogo = nullptr) {
        std::cout << "构造函数" << std::endl;
        this->name = Name;
        this->age = Age;

        this->stu_logo = new char[strlen(Stu_ogo)+1];
        strcpy(this->stu_logo, Stu_ogo);
    }
    stu(const stu& other_stu) {
        std::cout << "拷贝构造函数" << std::endl;
        this->name = other_stu.name;
        this->age = other_stu.age;

        this->stu_logo = new char[strlen(other_stu.stu_logo)+1];
        strcpy(this->stu_logo, other_stu.stu_logo);
    }
    stu& operator=(const stu& other_stu) {
        std::cout << "赋值构造函数" << std::endl;
        if (this == &other_stu) {
            return *this;
        }
        this->age = other_stu.age;
        this->name = other_stu.name;
        delete[] this->stu_logo;      //释放之前创建的对象
        this->stu_logo = nullptr;
        this->stu_logo = new char[strlen(other_stu.stu_logo)+1];
        strcpy(this->stu_logo, other_stu.stu_logo);
		
		return *this;
    }

    ~stu() {
        std::cout << "析构函数" << std::endl;
        delete[] this->stu_logo;
    }
	
	void show(){
		std::cout << "姓名 = " << name << std::endl;
	    std::cout << "   年龄 = " << age << std::endl; 
		std::cout << "   logo = " << stu_logo << std::endl;
	}
private:
    std::string name;
    int age;
    char* stu_logo;
};


int main()
{
    {
        char messg1[] = "hello world!";   
        char *logo1 = new char[strlen(messg1)+1];
        strcpy(logo1, messg1);
        stu demo1("张三",15, logo1);
		
		char messg2[] = "bye bye~";
		char *logo2 = new char[strlen(messg2)+1];
		strcpy(logo2, messg2);
		stu demo2("李四",17, logo2);
		
		stu demo3(demo1);
		demo3.show();
		std::cout << std::endl;
		demo1 = demo2;
		demo1.show();
    }
    return 0;
}