#include <iostream>
using namespace std;class Person
{const string name;int age;char sex;
public:Person():name("lisi"){cout << "Person无参构造" << endl;}Person(string name,int age,char sex):name(name),age(age),sex(sex){cout << "Person有参构造" << endl;}void show(){cout <<"person的show:"<< name << age << sex <<endl;}Person(const Person &other):name(other.name){this->age = other.age;this->sex=other.sex;cout << "Person的拷贝构造函数" << endl;}Person &operator=(const Person &other){if(&other!=this){string name=other.name;this->age=other.age;this->sex=other.sex;cout << "Person的拷贝赋值函数" << endl;}return *this;}
};
class Stu
{Person p1;double *pd;
public:Stu():pd(new double){cout << "Stu的无参构造" << endl;}Stu(string name,int age,char sex,double score):p1(name,age,sex),pd(new double(score)){cout << "Stu有参构造" << endl;}void show(){p1.show();cout << *pd <<endl;}Stu(const Stu &other):p1(other.p1){this->pd=other.pd;}Stu &operator=(const Stu &other){if(&other!=this){this->p1=other.p1;*(this->pd)=*(other.pd);cout << "Stu的拷贝赋值函数" << endl;}return *this;}
};
int main()
{Person p2("wangwu",20,'n');p2.show();Person p3=p2;p3.show();Person p4;p4=p2;p4.show();Stu s2("zhangsan",20,'n',99.2);s2.show();Stu s3=s2;s3.show();Stu s4;s4=s2;s4.show();return 0;
}

#include <iostream>
#include <cstring>
using namespace std;using namespace std;
class myString
{private:char *str;          //变化c风格的字符串int size;            //记录字符串的实际长度public://无参构造myString() : str(new char), size(0){str[0] = '\0';cout<<"无参构造"<<endl;}//有参构造myString(const char* s){size = strlen(s);str = new char[size + 1];strcpy(str, s);cout<<"有参构造"<<endl;}//拷贝构造myString(const myString &other){size = other.size;str = new char[size + 1];strcpy(str, other.str);cout<<"拷贝构造函数"<<endl;}//拷贝赋值函数myString& operator=(const myString &other){if (this != &other) {size = other.size;str = new char[size + 1];strcpy(str, other.str);cout<<"拷贝赋值函数"<<endl;}return *this;}//析构函数~myString(){delete[] str;cout<<"析构"<<endl;}//判空函数void empty(){if(size == 0){cout<<"空"<<endl;}else{cout<<"非空"<<endl;}}//size函数void mysize(){cout<<"size = "<<size<<endl;}//c_str函数char* c_str(){return str;}//at函数char &at(int pos){if (pos < 0 || pos >= size) {cout<<"位置不合法"<<endl;}return str[pos];}
};
int main()
{myString s1("hello");myString s2 = s1;myString s3;cout<<s1.at(4)<<endl;cout<<s1.c_str()<<endl;cout<<s2.at(4)<<endl;cout<<s2.c_str()<<endl;s2.empty();s2.mysize();return 0;
}