实验二

task4

Complex.hpp

#pragma once
#include<iostream>
#include<cmath>

using std::cout;
using std::endl;

class Complex
{
	public:
		Complex(float x=0,float y=0):
		    real{x},imag{y}{}
		Complex(const Complex& obj) :
			real{ obj.real }, imag{ obj.imag } {}
		
		double get_real() const {return real;}
		double get_imag() const {return imag;}
		void show() const ;
		void add(const Complex &obj);
		
		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,imag;
};
void Complex::show() const
{
	if (imag > 0)
		cout << real << '+' << imag << 'j';
	else if (imag < 0)
		cout << real << imag << 'j';
	else
		cout << real;
}
void Complex::add(const Complex &obj)
{
	real+=obj.get_real();
	imag+=obj.get_imag();
}
Complex add(const Complex &c1,const Complex &c2)
{
	float add_real=c1.real+c2.real;
	float add_imag=c1.imag+c2.imag;
	Complex c(add_real,add_imag);
	return c;
}
bool is_equal(const Complex &c1,const Complex &c2)
{
	if(c1.real==c2.real&&c1.imag==c2.imag)
	    return true;
	return false;
}
double abs(const Complex &c)
{
	return sqrt(pow(c.real,2)+pow(c.imag,2));
}

　　task4.cpp

#include "Complex.hpp"
#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 = ";
    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();
}

　　实验结果

 

 

task5

User.hpp

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

using std::string;
using std::cin;
using std::cout;
using std::endl;
using std::setw;

class User
{
    public:
        User(string x,string y="666666", string z="\0") :
            name{ x }, password{ y }, email{ z } {n++;}
        ~User() { n--;}
        void set_email();
        void change_passwd();
        void print_info() const;
        static void print_n() { cout <<"There are " <<n <<" users" << endl; }
    private:
        string name, password, email;
        static int n;
};

int User::n = 0;

void User::set_email()
{
    string s;
    cout << "Enter email address ：";
    cin >> s;
    email = s;
    cout << "email is set successfully" << endl;
}
void User::change_passwd()
{
    string old_password;
    cout << "Enter old password : ";
    int num;
    for (num=1;num<=3;++num)
    {
        cin >> old_password;
        if (password == old_password)
        {
            password = old_password;
            cout << "password is changed successfully" << endl;
            break;
        }
        else
            cout << "password input error.";

        if(num<=2)
            cout << "Please re-enter again : ";
    }
    if (num > 3)
        cout << "Please try after a while." << endl;
}
void User::print_info() const
{
    cout << std::left<<setw(12) << "name:" <<  name<<endl;
    cout << std::left<< setw(12) << "password:";
    for (int i = 1; i <= password.size(); ++i)
        cout<<"*";
    cout << endl;
    cout << std::left<< setw(12) << "email:" << email << endl;
}

　　

　task5.cpp

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

// 测试User类
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();
}

　　实验结果