实验二 类和对象

#pragma once
#include<iostream>
#include<cmath>
using namespace std;
class complex {
public:
    complex(double r = 0.0, double i = 0.0) :real(r), imag(i){}
    complex(complex& p) :real(p.real), imag(p.imag){}
    double get_real() const { return real; }
    double get_imag() const { return imag; }
    void add(const complex& p) { real += p.real; imag += p.imag; }
    void show() const;
private:
    double real, imag;
    friend complex add(const complex& p1,const  complex& p2);
    friend bool is_equal (const complex& p1, const complex& p2);
    friend double abs(const complex& p);
};
void complex::show()const {
    cout << real;
    if (imag > 0) cout << "+" << imag << "i";
    else if (imag < 0) cout << imag << "i";
}
complex add(const complex& p1, const  complex& p2) {
    complex p;
    p.real =p1.real + p2.real;
    p.imag = p1.imag +p2.imag;
    return p;
}
bool is_equal (const complex& p1, const  complex& p2) {
    if (p1.real == p2.real && p1.imag == p2.imag)
        return true;
    else return false;
}
double abs(const complex& p) {
    double m = sqrt(p.real * p.real + p.imag * p.imag);
    return m;
}

task.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();
}

user.hpp

#pragma once
#include<iostream>
#include<string>
#include<cstring>
using namespace std;
class user {
private:
    string name;
    string passwd;
    string email;
    static int n;
public:
    user(string name0, string passwd0 = "111111", string email0 = "111111");
    void set_email() { cout << "enter email address: "; cin >> email; cout << "email is set successfully..." << endl; }
    void change_passwd();
    void print_info() const;
    void static print_n() { cout << "there are "<<n <<" users" << endl; }
};
user::user(string name0, string passwd0, string email0) :name(name0), passwd(passwd0), email(email0) { n++; }
int user::n = 0;
void user::change_passwd () {
    string old = passwd;
    int count;
    cout <<  "enter old password: ";
    cin >> passwd;
    count = 1;
    while (old!=passwd&&count<3) {
        cout << "password input error.please re-enter again: ";
        cin >> passwd;
        count++;
        if (count == 3) {
            cout << "password input error.please try after a while." << endl;
        }
    }
    if (count != 3) {
        cout << "enter new passwd: ";
        cin >> passwd;
        cout << "new passwd is set successfully..." << endl;
    }
}
void user::print_info() const {
    int m;
    cout << "name: " << name << endl;
    cout << "passwd: ";
    m = size(passwd);
    while (m--) cout << "*";
    cout << endl;
    cout << "email: " << email << endl;
}

task.cpp

#include<iostream>
#include"user.hpp"
void test() {
    using std::cout;
    using std::endl;
    cout << "testong 1......\n";
    user user1("jonny", "92197", "[email protected]");
    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();
}