实验一 类与对象

实验任务3 Complex类的自我实现

​ 简要说明：不使用C++标准库，自行设计并实现一个复数类Complex，并满足简单的使用需求。

​ 程序由 Complex.hpp 与 task3.cpp 两部分构成，分别完成复数类定义及实现，主程序展示的功能。

​ Complex.hpp代码如下：

​

#ifndef COMPLEX_HPP
#define COMPLEX_HPP

#include <iostream>
#include <cmath>
using std::cout;
using std::endl;

class Complex {
public:
	Complex(double r = 0, double i = 0) : real(r), image(i) {}
	Complex(const Complex &c) : real(c.real), image(c.image) {}
	double get_real();
	double get_imag() const;
	void show() const;
	void add(const Complex &c);
	friend Complex add(const Complex &c1, const Complex &c2);
	friend bool is_equal(const Complex& c1, const Complex& c2);
	friend double abs(const Complex& c);
private:
	double real;
	double image;
};

double Complex::get_real() { return real; }

double Complex::get_imag() const { return image; }

void Complex::show() const {
	if(real == 0)
		cout << image << "i" << endl;
	if(image == 0)
		cout << real << endl;
	if(image < 0)
	cout << real << " - " << -image << "i" << endl;
}

void Complex::add(const Complex &c) {
	real += c.real;
	image += c.image;
}

Complex add(const Complex& c1, const Complex& c2) {
	Complex r;
	r.real = c1.real + c2.real;
	r.image = c1.image + c2.image;
	return r;
}

bool is_equal(const Complex& c1, const Complex& c2) {
	if (c1.real == c2.real && c1.image == c2.image) {
		return true;
	}
	else {
		return false;
	}
}

double abs(const Complex& c) {
	double ret = sqrt(c.real * c.real + c.image * c.image);
	return ret;
}

#endif // !COMPLEX_HPP

​

​ 主程序 task3.cpp代码如下：

​

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

int main()
{
    using namespace std;

    Complex c1(1, -2);
    const Complex c2(6.7);
    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;
}

​ 使用更改的数据的测试结果：

​

实验任务4 User类的设计与实现

​ 简要说明：设计并实现一个用户类User， 满足基础的创建用户，修改密码与邮箱的功能，并进行简单的合法校验。

程序由 User.hpp 与 task4.cpp 两部分构成，分别完成用户类定义及实现，主程序展示的功能。

User.hpp 代码如下：

​

#ifndef USER_HPP
#define USER_HPP

#include <iostream>
#include <string>
using std::string;
using std::cin;
using std::cout;
using std::endl;


class User {
public:
	User(string name, string pwd="111111", string email="") :
		name(name), password(pwd), email(email) 
	{
		cnt++;
	}
	void set_email();
	void change_passwd();
	void print_info();
	static void print_n();

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

int User::cnt = 0;

void User::set_email() {
	string newemail;
	cout << "Enter email address: ";
	cin >> newemail;
	while (newemail.find('@') == -1) {
		cout << "Wrong! There must be an '@' in your email address!\nPlease re_enter again: ";
		cin >> newemail;
	}
	email = newemail;
	cout << "email is set sucessfully..." << endl;
}

void User::change_passwd() {
	string oldpwd;
	string newpwd;
	int t = 0;
	cout << "Enter old password: ";
	cin >> oldpwd;
	while (true) {	
		if (oldpwd == password) {
			cout << "Enter new password: ";
			cin >> newpwd;
			while (newpwd.length() != 6) {
					cout << "The password can only contain 6 characters!\nPlease re_enter again: ";
					cin >> newpwd;
			}
			password = newpwd;
			cout << "new password is set successfully..." << endl;
			break;
		}
		else {
			if (t >= 2) {
				cout << "Password input error. Please try after a while." << endl;
				break;
			}
			cout << "Password input error. Please re_enter again: ";
			cin >> oldpwd;
			t++;
		}
	}
}

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

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

#endif

task4.cpp 代码如下：

​

#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();
}

使用更改的数据的测试结果：

​

​