實驗一 類與對象

實驗任務三

// Complex.hpp

#include<iostream>
#include<cmath> 
using namespace std;

class Complex
{
    public:
        Complex(double r = 0, double m = 0) : real(r), imag(m) {} ;
        Complex(Complex &c) : real(c.real), imag(c.imag) {} ;
        double get_real() const
        {
            return real;
        }
        double get_imag() const
        {
            return imag;
        }
        void show() const
        {
            cout<<real<<" + "<<imag<<"i"<<endl;
        }
        void add(Complex const &c)
        {
            real += c.real;
            imag += c.imag;
        }
        friend Complex add(Complex const &c1, Complex const &c2);
        friend bool is_equal(Complex const &c1, Complex const &c2);
        friend double abs(Complex const &c);
    private:
        double real;
        double imag;
};

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

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

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

// task3.cpp

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

int main()
{
    using namespace std;

    Complex c1(2, -4);
    const Complex c2(5.5);
    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(c3) = ";
    cout << abs(c3) << 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;
}

 

 

// 實驗任務四

User.hpp

#include<iostream>
#include<string>
using namespace std;

class User
{
    public:
        User(string a, string p = "111111", string e = "") : name(a), password(p), email(e) { n++; }
        User(User &u) : name(u.name), password(u.password), email(u.email) { n++; }
        void set_email()
        {
            cout<<"Enter email address:";
            cin>>email;
            while(email.find('@') == -1)
            {
                cout<<"The @ should be included. Plesae input again:";
                cin>>email; 
            }
            cout<<"email is set sucessfully..."<<endl; 
        }
        void change_passwd();
        void print_info()
        {
            cout<<"name: "<<name<<endl;
            cout<<"passwd:******"<<endl;
            cout<<"email :"<<email<<endl;
        }
        static void print_n()
        {
            cout<<"there are "<<n<<" users."<<endl;
        }
        ~User() { n--; }
    private:
        string name;
        string password;
        string email;
        static int n;
};

int User::n = 0;

void User::change_passwd()
{
    int i = 0;
    string temp;
    while(i != 3)
    {
        if(i == 0)
            cout<<"Enter old password:";
        else
            cout<<"Please re_enter again:";
        cin>>temp;
        if(temp == password)
        {
            cout<<"Enter new password:";
            cin>>password;
            while(password.length() != 6)
            {
                cout<<"The length of the new password should be six.";
                cout<<"Please input again:";
                cin>>password;
            }
            cout<<"new password is set sucessfully..."<<endl;
            return;
        }
        else
        {
            cout<<"password input error.";
            i++;
        } 
    }
    if(i == 3)
        cout<<"Please try after a while."<<endl; 
}

 

//task4.cpp

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

int main()
{
    using namespace std;

    cout << "testing 1......" << endl;
    User user1("Jonny", "273274", "[e-mail]");
    user1.print_info();
    cout << endl
         << "testing 2......" << endl
         << endl;
    User user2("Leonard");
    user2.change_passwd();
    user2.set_email();
    user2.print_info();

    User::print_n();
}