实验一 类与对象

试验任务3

complex.hpp文件源码

#ifndef COMPLEX_HPP
#define COMPLEX_HPP

// complex类的定义
#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

// Complex类的声明
class Complex
{
public:
    Complex();
    Complex(double a, double b = 0);
    Complex(const Complex &c);

    void show() const;          //用于输出复数
    double get_imag() const;    //返回复数虚部
    double get_real() const;    //返回复数实部
    void add(const Complex &c); //用于把一个复数加到自身

    friend double abs(const Complex &c);                        //求复数的模
    friend bool is_equal(const Complex &c1, const Complex &c2); //用于判断两个复数是否相等
    friend Complex add(const Complex &c1, const Complex &c2);   //用于实现两个复数相加，返回复数

private:
    double real; //实部
    double imag; //虚部
};

// 默认构造函数
Complex::Complex() {}

// 带参数的构造函数
Complex::Complex(double a, double b) : real{a}, imag{b} {}

// 复制构造函数
Complex::Complex(const Complex &c) : real{c.real}, imag{c.imag} {}

// 用于输出复数
void Complex::show() const
{
    if (imag == 0)
        cout << real;
    else if (imag < 0)
        cout << real << " - " << -imag << "i";
    else
        cout << real << " + " << imag << "i";
}

// 返回复数实部
double Complex::get_real() const
{
    return real;
}

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

//用于把一个复数加到自身
void Complex::add(const Complex &c)
{
    real += c.real;
    imag += c.imag;
}

//求复数的模
double abs(const Complex &c)
{
    return sqrt(c.real * c.real + c.imag * c.imag);
}

//用于判断两个复数是否相等
bool is_equal(const Complex &c1, const Complex &c2)
{
    if (c1.imag == c2.imag && c1.real == c2.real)
        return true;
    else
        return false;
}

//  用于实现两个复数相加，返回复数
Complex add(const Complex &c1, const Complex &c2)
{
    Complex c;
    c.real = c1.real + c2.real;
    c.imag = c1.imag + c2.imag;
    return c;
}

#endif

task3.cpp源码

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

int main()
{
    using namespace std;

    Complex c1(1, -2);
    const Complex c2(6.9);
    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;
}

实验结果截图

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 实验任务4

User.hpp源码

#ifndef USER_HPP
#define USER_HPP

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

class User
{
public:
    User();
    User(string name0, string password0 = "111111", string email0 = "");
    void set_email();
    void change_passwd();
    void print_info();
    static void print_n();

private:
    string name;
    string password;
    string email;
    static int count;
};

int User::count = 0;

User::User() { count++; }

User::User(string name0, string password0, string email0) : name{name0}, password{password0}, email{email0} { count++; }

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

void User::change_passwd()
{
    string pwd, new_pwd;
    int num = 0;
    cout << "Enter old password: ";
    cin >> pwd;
    cout << endl;
    num++;
    while (pwd != password && num < 3)
    {
        cout << "password input error. Please re-enter again: ";
        cin >> pwd;
        cout << endl;
        num++;
        if (num == 3)
            cout << "password input error. Please try after a while." << endl;
    }
    if (pwd == password)
    {
        cout << "Enter new password: ";
        cin >> new_pwd;
        cout << endl;
        password = new_pwd;
        cout << "new passwd is set sucessfully..." << endl;
    }
}

void User::print_info()
{
    cout << setw(8) << left << "name:" << name << endl;
    cout << setw(8) << left << "passwd: "
         << "******" << endl;
    cout << setw(8) << left << "email: " << email << endl;
}

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

#endif

task4.cpp源码

#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();
}

实验结果截图

 

 

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实验总结