实验一 类与对象

#ifndef COMPLEX_HPP
#define COMPLEX_HPP

//complex类定义
#include<iostream>
#include<math.h> 
using namespace std;
class Complex
{
public:
    
    Complex();
    Complex(double x);
    Complex(double a, double b);
    Complex(const Complex &p);
    
    double get_real()const;
    double get_imag()const ;
    void show() const;
    void add(const Complex &c2);

//友元函数    
    friend Complex add(const Complex &c1, const Complex &c2);
    friend bool is_equal(const Complex &c1, const Complex &c2);
    friend double abs(const Complex &c1);

private:
    double m_real;
    double m_imag;
}; 

Complex::Complex() {}

Complex::Complex(double x): m_real{x}, m_imag{0} {}

Complex::Complex(double a, double b): m_real{a}, m_imag{b} {}

Complex::Complex(const Complex &p): m_real{p.m_real}, m_imag{p.m_imag} {} 
 
//返回复数实部 
double Complex::get_real() const
{
    return  m_real;
} 

//返回复数虚部 
double Complex::get_imag() const
{
    return m_imag;
} 

//输出复数 
void Complex::show() const
{
    if(m_real < 0 && m_imag < 0)
    cout << "-" << " " <<fabs(m_real )<< " " <<  "-" << " " << fabs(m_imag )<< "i";
    else if(m_real < 0 && m_imag > 0)
    cout << "-" << " " << fabs(m_real )<< " " <<"+" << " " << fabs(m_imag )<< "i";
    else if(m_real < 0 && m_imag == 0)
    cout << "-" << " " << fabs(m_real);
    else if(m_real > 0 && m_imag < 0)
    cout <<fabs(m_real )<< " " <<  "-" << " " << fabs(m_imag )<< "i";
    else if(m_real > 0 && m_imag > 0)
    cout << fabs(m_real )<< " " <<"+" << " " << fabs(m_imag )<< "i";
    else if(m_real > 0 && m_imag == 0)
    cout << fabs(m_real);    
    else if(m_real == 0 && m_imag < 0)
    cout <<  "-" << " " << fabs(m_imag )<< "i";
    else if(m_real == 0 && m_imag > 0)
    cout << fabs(m_imag )<< "i";
    else if(m_real == 0 && m_imag == 0)
    cout << "0";        
    
} 

//复数加到自身 
void Complex::add(const Complex &c1)
{
    m_real += c1.m_real ;
    m_imag += c1.m_imag ;
}

//友元函数，复数相加 
Complex add(const Complex &c1, const Complex &c2)
{
    Complex temp;
    temp.m_real = c1.m_real + c2.m_real;
    temp.m_imag = c1.m_imag + c2.m_imag;
    
    return temp;
} 

//判断复数是否相等 
bool is_equal(const Complex &c1, const Complex &c2)
{
    if(c1.get_imag() == c2.get_imag() && c1.get_real() == c2.get_real() )
    return true;
    else 
    return false;
}

//复数取模 
double abs(const Complex &c1)
{
    return sqrt(c1.get_imag() *c1.get_imag() + c1.get_real() *c1.get_real() );
}

#endif

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

int main()
{
    using namespace std;

    Complex c1(3, -6);
    const Complex c2(5.5);
    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;
}

 

实验任务四

# user.cpp

#ifndef USER_HPP
#define USER_HPP

#include<iostream>
#include<string>
using namespace std;

int cnt = 1;
class User
{
public:
    User(string name);
    User(string name, string passwd, string email);
    
    void set_email();
    void change_passwd();
    void print_info();
    
    static void print_n();
    
private:
    string m_name;
    string m_passwd;
    string m_email;
    static int n;//记录有几个user 
};

int User::n = 0;

User::User(string name) : m_name{name}, m_passwd{"111111"}, m_email{""}
{
    n++;
}

User::User(string name, string passwd, string email) :m_name{name}, m_passwd{passwd},m_email{email} 
{
    n++;
}

void User::set_email() 
{
    string email0;
    cout << "Enter email sddress: ";
    cin >> email0;
    m_email = email0;
    cout << "email is set successfully..." << endl;
} 

void User::change_passwd() 
{
    string oldpasswd;
    string newpasswd;
    cout << "Enter old password: ";
    cin >> oldpasswd;
    while(cnt <= 3)
    {
        if(oldpasswd != m_passwd)
        {
            cnt++;
            if(cnt == 4) 
            break;
             cout << "password input error. Please re-enter again: ";
            cin >> oldpasswd;
            
            
        }
        else break;
            
    }
    if(cnt <= 3)
    {
        cout << "Enter new passwd: ";
        cin >> newpasswd;
        cout << "new passwd is set successfully..." << endl;
    }
    else
    {
        cout << "password input error. Please try after a while." << endl;
    }
}

void User::print_info() 
{
    cout << "name:   " << m_name << endl;
    cout << "passwd: " << "******" << endl;
    cout << "email: " << m_email << endl;
} 

void User::print_n() 
{
    cout << "there are " << n << " users." << endl;
}

#endif  

 

#main.cpp

#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_passwd();
    user2.set_email();
    user2.print_info();

    User::print_n();
}