实验二 类与对象（2）

4

#pragma once

#include<iostream>
#include<iomanip>
#include<complex>

using namespace std;

class Complex {
public:
	double re, im, ab;

	Complex();
	Complex(double x);
	Complex(double x, double y);
	Complex(const Complex &obj);
	double get_real() const {return re;};
	double get_imag() const {return im;};
	void show() const;
	void add(Complex obj);
	friend Complex add(Complex c1,Complex c2);
	friend bool is_equal(Complex c1, Complex c2);
	friend double abs(Complex obj);
};

Complex::Complex() {
	re = 0;
	im = 0;
}

Complex::Complex(double x) {
	re = x;
	im = 0;
}

Complex::Complex(double x, double y){
	re = x;
	im = y;
}

Complex::Complex(const Complex& obj){
	re = obj.re;
	im = obj.im;
}

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

void Complex::add(Complex obj) {
	re += obj.re;
	im += obj.im;
}

Complex add(Complex c1, Complex c2) {
	Complex c3;
	c3.re = c1.re + c2.re;
	c3.im = c1.im + c2.im;
	return c3;
}

bool is_equal(Complex c1, Complex c2) {
	if (c1.re == c2.re && c1.im == c2.im)
		return 1;
	else 
		return 0;
}

double abs(Complex obj) {
	double ab;
	ab = sqrt(obj.re * obj.re + obj.im * obj.im);
	return ab;
}

　　

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

void test() {
	using namespace std;

	Complex c1(3, -4);
	const Complex c2(4.5);
	Complex c3(c1);

	cout << "c1=";
	c1.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();
}

　　

5

#pragma once
#include<iostream>
#include<string>
#include<iomanip>

using namespace std;

class Uesr {
public:
	User(string name, string password = "111111", string email = "") :
		na{ name }, pa{ password }, em{ email };

	void set_email()
	{
		cin >> em;
	};

	void change_passwd()
	{
		cout << "Enter old password:";
		int i;
		for (i = 0;i < 3;i++)
		{
			string ep;
			cin >> ep;
			if (ep.compare(pa) != 0)
			{
				if (i == 2)
					cout << "password input error. Please try after a while." << endl;
				else
					cout << "password input error. Please re-enter again:";
			}
			else
			{
				cout << "Enter new passwd:";
				cin >> pa;
				cout << "new passwd is set successfully..." << endl;
				break;
			}
		}
	};

	void print_info() 
	{
		cout << "name:" << na << endl;
		string a(pa.length(), '*');
		cout << "passwd:" << a << endl;
		cout << "email:" << em << endl;
	};


	string na, pa, em;
};

　　

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

void test() {
    using std::cout;
    using std::endl;

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

    cout << endl
        << "testing 2......\n\n";

    User user2("Leonard");
    user2.change_passwd();
    user2.set_email();
    user2.print_info();

    cout << endl;
    User::print_n();
}

int main() {
    test();
}