实验2 类和对象（2）

实验任务4

#pragma once

#include<iostream>
#include<cmath>

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

class Complex{
    public:
        //构造函数 
        Complex(float r = 0.0, float i = 0.0): real{r}, imag{i} {}
        Complex(const Complex &obj): real{obj.real}, imag{obj.imag} {}
    
    public:
        //普通成员函数
        float get_real() const { return real; }
        float get_imag() const { return imag; } 
        void show() const;
        void add(const Complex &obj); 
        
        //友源函数
        friend Complex add(const Complex &c1, const Complex &c2) ;
        friend bool is_equal(const Complex &c1, const Complex &c2);
        friend double abs(const Complex &obj); 
        
    private:
        float real; // 复数的实部
        float imag; // 复数的虚部 
};
 
void Complex::show() const {
    if(imag > 0){
        cout << real << " + " << imag << "i";
    }
    else if(imag < 0){
        cout << real << " - " << abs(imag) << "i";
    }
    else{
        cout << real ;  
    } 
     
}

void Complex::add(const Complex &obj) {
    real += obj.real;
    imag += obj.imag;
}

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

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 &obj) {
    return sqrt(obj.real * obj.real + obj.imag * obj.imag);
}

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

// 类测试
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();
}

测试结果截图：

 

 

 

 

实验任务5

#pragma once

#include<iostream>
#include<string> 

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

class User{
    public:
        User(string n, string p = "111111", string e = "");
        void set_email() ;
        void change_passwd();
        void print_info();
        static void print_n() { cout << "there are " << count << " users" <<endl; }
    
    public:
        static int count;
        
    private:
        string name;
        string passwd;
        string email;
};

int User::count = 0;

User::User(string n, string p /*= "111111"*/, string e /*= "111111"*/){
    name = n;
    passwd = p;
    email = e;
    count++;
}

void User::set_email() {
    string s1;
    cout << "Enter email address: ";
    cin >> s1; 
    email = s1;
    cout << "email is set successfully..." << endl;
}

void User::change_passwd() {
    cout << "Enter old password: ";
    int times = 0;
    while(times < 3){
        string s1;
        cin >> s1;
        if(s1 == passwd){
            cout << "Enter new passwd: ";
            string s1;
            cin >> s1;
            passwd = s1;
            cout << "new passwd is set successfully..." << endl; 
            break;
        }
        if(times < 2)
        cout << "password input error. Please re-enter again:";
        times++;
    }
    if(times >= 3) cout << "passwd input error. Please try affter a while." << endl;
}

void User::print_info(){
    cout << "name: " << name << endl;
    cout << "passwd: ";
    string s1(passwd.length(), '*');
    cout << s1 << endl;
    cout << "email: " << email << endl;
}

#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();
}

测试代码：