实验2 类与对象（2）

Task 4

hpp文件如下

#pragma once

#include<iostream>
#include<complex>

class Complex
{
public:
	Complex();
	Complex(double r,double i = 0.0);
	Complex(const Complex& obj);
	double get_real()const { return real; };
	double get_imag()const { return img; };
	void show()const;
	void add(Complex c1);
	friend Complex add(Complex c1,Complex c2);
	friend bool is_equal(Complex c1,Complex c2);
	friend double abs(Complex c);
private:
	double real;
	double img;
};
Complex::Complex() :real{ 0 }, img{ 0 } {}
Complex::Complex(double r, double i): real{ r }, img{ i } {}
Complex::Complex(const Complex& obj) :real{ obj.real }, img{ obj.img } {}
void Complex::add(Complex c1){
	real += c1.real;
	img += c1.img;

}
Complex add(Complex c1, Complex c2) {
	Complex c3;
	c3.real = c1.real + c2.real;
	c3.img = c1.img + c2.img;
	return c3;
}
bool is_equal(Complex c1, Complex c2)
{
	if (c1.img == c2.img && c1.real == c2.real)
		return 1;
	else
		return 0;
 }
double abs(Complex c)
{
	double count = 0;
	count = sqrt(c.img * c.img + c.real * c.real);
	return count;
}

void Complex::show()const{
	if (img > 0)
		std::cout << real << "+" << img << "i" << std::endl;
	else if (img < 0)
		std::cout << real << img << "i" << std::endl;
	else if (img == 0)
		std::cout << real << std::endl;
}

cpp文件如下：

#include "Complex.hpp"
#include <iostream>
// 类测试
void test() {
	using namespace std;
	Complex c1(3, -4);
	const Complex c2(7.8);
	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;
}
int main() {
	test();
}

运行结果截图

Task 5

hpp文件如下：

#pragma once
#include<iostream>;
#include<string>
class User {
public:
	User(std::string name0, std::string password0 = "111111",std::string email0 = "");
	void set_email();
	void change_passwd();
	void print_info();
	void static print_n() {
		std::cout << "共有 " << n << " 名用户" << std::endl;
	}
private:
	std::string name;
	std::string email;
	std::string passwd;
	static int n;


};
int	User::n = 0;
User::User(std::string name0,  std::string password0,std::string email0) :name{ name0 }, email{ email0 }, passwd{ password0 } { n++; }
void User::set_email() {
	std::string email1;
	std::cout << "请用户用键盘输入邮箱地址！" << std::endl;
	std::cin >> email1;
	if (email1 != "")
	{
		email = email1;
		std::cout << "邮箱设置成功！" << std::endl;
	}
	else
	std::cout << "未设置邮箱，将使用默认值！" << std::endl;
		
}
void User::change_passwd() {
	std::cout << "请输入旧密码！" << std::endl;
	std::string password;
	for (int i = 0; i < 3; i++)
	{
		flag:
		std::cin >> password;
		if (password != passwd)
		{
			std::cout << "原密码不正确,请重新输入！";
			std::cout << "已连续输入错误" << i + 1 << "次！"<<std::endl;
			if (i == 2)
			{
				std::cout << "已连续输入三次错误密码，请稍后再试。"<<std::endl;
				goto flag;
			}

		}
		else if (password == passwd)
		{
			std::cout << "原密码验证成功，请输入新密码！"<<std::endl;
			std::cin >> passwd;
			std::cout << "密码修改成功！" << std::endl;
			break;
		}
	}

}
void User::print_info() {
	int length = passwd.length();
	std::cout << "用户名为：" << name << std::endl;
	std::cout << "邮箱为：" << email << std::endl;
	std::cout << "密码为：";
	while (length--)
	{
		std::cout << "*";
		if (length == 0)
			std::cout << std::endl;
	}
}

cpp文件如下：

#include "User.hpp"
#include <iostream>
// 测试User类
void test() {
	using std::cout;
	using std::endl;
	cout << "testing 1......\n";
	User user1("Li", "123456", "lkx@hotmail.com");
	user1.print_info();
	cout << endl
		<< "testing 2......\n\n";
	User user2("lixuan");
	user2.change_passwd();
	user2.set_email();
	user2.print_info();
	cout << endl;
	User::print_n();
}
int main() {
	test();
	}

运行结果如下：

实验心得

1.对于类与对象的用法概念知识点等加深了认识。

2.对于const等修饰词有了更为深刻的认识。