实验一类与对象

任务三源码：

#ifndef COMPLEX_HPP
#define COMPLEX_HPP
#include <iostream>
class Complex{
public:
    Complex(){};
    Complex(double r,double i=0):real(r),imag(i){};
    Complex(Complex &c);
    double get_real()const;
    double get_imag()const;
    void show()const;
    void add(const Complex &c);
    friend Complex add(Complex &c1,Complex &c2);
    friend bool is_equal(Complex &c1,const Complex &c2);
    friend double abs(Complex &c);
private:
    double real,imag;};

Complex::Complex(Complex &c):real(c.real),imag(c.imag){};
double Complex::get_real()const
{
    return real;}
double Complex::get_imag()const
{
    return imag;}
void Complex::show()const
{
    if(imag>=0)
        std::cout<<real<<"+"<<imag<<"i";
    else if(imag<0)
        std::cout<<real<<imag<<"i";        
    }
void Complex::add(const Complex &c)
{
    real+=c.real;
    imag+=c.imag;}
Complex add(Complex &c1,const Complex &c2)
{
    return Complex(c1.get_real()+c2.get_real(),c1.get_imag()+c2.get_imag());
}
bool is_equal(Complex &c1,const Complex &c2)
{
    if(c1.real==c2.real&&c1.imag==c2.imag)
        return true;
    else
        return false;}
double abs(Complex &c)
{
    return sqrt(c.real*c.real+c.imag*c.imag);}
#endif

#include"Complex.hpp"
#include <iostream>

int main()
{
using namespace std;

Complex c1(3,-5);
const Complex c2(1.2);
Complex c3(c1);

cout << "c1 = ";
c1.show();
cout << endl;

cout << "c2 = ";
c2.show();
cout << endl;
cout << "c2.imag = " << c2.get_imag() << endl;

cout << "c3 = ";
c3.show();
cout << endl;

cout << "abs(c1) = ";
cout << abs(c1) << endl;

cout << boolalpha;
cout << "c1 == c3 : " << is_equal(c1, c3) << endl;
cout << "c1 == c2 : " << is_equal(c1, c2) << endl;

Complex c4;
c4 = add(c1, c2);
cout << "c4 = c1 + c2 = ";
c4.show();
cout << endl;

c1.add(c2);
cout << "c1 += c2, " << "c1 = ";
c1.show();
cout << endl;
}

任务四源码：

#ifndef USER_HPP
#define USER_HPP
#include<iostream>
#include<string>
using namespace std;

class User{
public:
    User(string n,string p="111111",string e="");
    void set_email();
    void change_passd();
    void print_info();
    static void print_n();
private:
    string name,password,email;
    static int count;

};


int User::count=0;
User::User(string n,string p,string e):name(n),password(p),email(e){count++;};
void User::print_n()
{
    cout<<"there are "<<count<<" users";}
void User::print_info()
{
    
    cout<<"name:"<<name<<endl
        <<"password:******"<<endl
        <<"email:"<<email<<endl;
}
void User::change_passd()
{
    
    string passwrd;
    cout<<"Enter old password:";
    cin>>passwrd;
    
    for(int i=0;i<3;i++)
        if(passwrd==password)
            {cout<<"Enter new password:";
            cin>>passwrd;
            password=passwrd;
            cout<<"new passwd is set successfully..."<<endl;
            break;}
        else
            {if(i==2)
            cout<<"password intput error.Please try after a while."<<endl;
            else
                {cout<<"password intput error.Please re-enter again:";
                 
                 cin>>passwrd;}
            
            
        }

    }
void User::set_email()
{
    
    
    cout<<"Enter email address:";
    cin>>email;
    
    cout<<"email is set successfully..."<<endl;}

#endif

#include "User.hpp"
#include <iostream>

int main()
{
    using namespace std;

    cout << "testing 1......" << endl;
    User user1("Jonny", "92197", "xyz@hotmail.com");
    user1.print_info();

    cout << endl
         << "testing 2......" << endl
         << endl;
    User user2("Leonard");
    user2.change_passd();
    user2.set_email();
    user2.print_info();

    User::print_n();
}