实验2 类和对象_基础编程2

//第一个任务简单Complex类

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

class Complex {
public:
    Complex(double x0 = 0, double y0 = 0); // 构造函数
    Complex(const Complex& c); // 拷贝构造函数
    ~Complex(){}; // 析构函数
    double get_real() const; // 获取实部
    double get_imag() const; // 获取虚部
    void show() const; // 显示复数
    void add(const Complex &c); // 复数相加
    friend Complex add(const Complex &c1, const Complex &c2); // 友元函数，复数相加
    friend bool is_equal(const Complex &c1, const Complex &c2); // 友元函数，判断两个复数是否相等
    friend void abs(const Complex &c); // 友元函数，计算复数的模

private:
    double real, imag; // 实部和虚部
};
Complex::Complex(double x0, double y0) : real{x0}, imag{y0} {} // 构造函数的实现

Complex::Complex(const Complex& c) : real{c.real}, imag{c.imag} {} // 拷贝构造函数的实现

double Complex::get_real() const {
    return real;
}

double Complex::get_imag() const {
    return imag;
}

void Complex::show() const {
    std::cout << real;
    if (imag > 0)
        std::cout << "+" << imag << "i";
    if (imag < 0)
        std::cout << imag << "i";
}

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

Complex add(const Complex& c1, const Complex& c2) {
    Complex c3;
    c3.real = c1.real + c2.real;
    c3.imag = c1.imag + c2.imag;
    return c3;
}

void abs(const Complex& c) {
    double mo = sqrt(c.real * c.real + c.imag * c.imag);
    std::cout << mo;
}

bool is_equal(const Complex& c1, const Complex& c2) {
    return c1.real == c2.real && c1.imag == c2.imag;
}
#pragma once
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)=";
    abs(c1);
    cout << 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;
}

#include"Complex.hpp"
int main() {
    test();
    return 0;
}

//第二个User类简单版本

#pragma once

#include<iostream>
#include <string>
#include <vector>

using namespace std; 

class User {
public:
    // 构造函数，包含密码和电子邮件的默认值
    User(const string& name0, const string& passwd0 = "111111", const string& email0 = "");

    // 析构函数
    ~User();

    // 设置用户的电子邮件地址
    void set_email();

    // 更改用户的密码
    void change_passwd();

    // 打印用户信息
    void print_info() const;

    // 静态方法，用于打印用户对象的数量
    static void print_n();

private:
    string name, email, passwd; // 用户数据
    int c = 3; // 最大密码更改尝试次数设置成私有，防止篡改无限多次 

    // 验证电子邮件地址有没有@ 
    void isValidEmail(const stri

//Usermain.cpp
#include "User1.hpp"
#include<iostream>
using namespace std;
void test() {
    cout << "测试 1......\n";
    User user1("Jonny", "92197", "xyz@hotmail.com");
    user1.print_info();
    cout << endl << "测试 2......\n\n";
    User user2("Leonard");
    user2.change_passwd();
    user2.set_email();
    user2.print_info();
    cout << endl;
    User::print_n();
}

int main() {
    test();
}

ng& oldEmail0, const string& newEmail0);

private:
    static int n; // 用户对象数量的静态成员变量
};

int User::n = 0;

User::User(const string& name0, const string& passwd0, const string& email0)
    : name(name0), passwd(passwd0), email(email0) {
    ++n;
}

User::~User() {
    --n;
}

//错误1：//默认形参只能声明时候写  
void User::isValidEmail(const string& oldEmail0, const string& newEmail0) {
    string newEmail = newEmail0;
    string oldEmail = oldEmail0;
    vector<string> v{oldEmail, newEmail};
    for (auto& s : v) {
        //s.npos 是std::string类中的一个很大的静态成员变量 
        auto pos = s.find("@");
        if (pos == string::npos)// 
         {
            cout << "Email format is missing @" << endl;
        } else {
            email = newEmail;
            cout << "Email is set successfully" << endl;
        }
    }
}

void User::set_email() {
    cout << "Enter email address: ";
    string newEmail;
    cin >> newEmail;
    cout << newEmail;
    isValidEmail(email, newEmail);
}

void User::change_passwd() {
    cout << "Name: " << name << endl;
    string hidden_passwd(passwd.size(), '*');
    cout << "Password: " << hidden_passwd << endl;
    cout << "Email: " << email;
    cout << "Enter old password: ";
    string oldPasswd, newPasswd;
    int i = c;
    while (i) {
        cin >> oldPasswd;
        if (oldPasswd == passwd) {
            cout << "Enter new password: ";
            cin >> newPasswd;
            passwd = newPasswd;
            cout << "New password is set successfully..." << endl;
            break;
        } else {
            i--;
            if (i != 0)
                cout << "Password input error. Please re-enter: ";
        }
        if (i == 0) {
            cout << "Password input error. Please try again later.";
            exit(1);//强行退出函数 
        }
    }
}

void User::print_info() const {
    cout << "Name: " << name << endl;
    string hidden_passwd(passwd.size(), '*');
    cout << "Password: " << hidden_passwd << endl;
    cout << "Email: " << email << endl;
}

void User::print_n() {
    cout << "There are " << n << " users." << endl;
}

//Usermain.cpp
#include "User1.hpp"
#include<iostream>
using namespace std;
void test() {
    cout << "测试 1......\n";
    User user1("Jonny", "92197", "xyz@hotmail.com");
    user1.print_info();
    cout << endl << "测试 2......\n\n";
    User user2("Leonard");
    user2.change_passwd();
    user2.set_email();
    user2.print_info();
    cout << endl;
    User::print_n();
}

int main() {
    test();
}

//第三个任务课本银行类

//account.h
#pragma once
class SavingsAccount{ //储存账户类
  private:
  int id;                      //账号
  double balance;              //余额
  double rate;                 //存款年利率
  int lastDate;                //上次变更余额时期 
  double accumulation;         //余额按日累加之和
  static double total;
  //记录一笔账，date为日期，amount为余额，desc为说明
  void record(int date,double amount);
  //获得到指定日期为止的存款金额按日累计值
  double accumulate(int date) const{
return accumulation + balance * (date-lastDate);}
  
  public:
  //构造函数
  SavingsAccount(int date, int id, double rate);
  int getId()const{return id;}
  double getBalance()const{return balance;}
  double getRate()const{return rate;}
  static double getTotal(){ return total;}
  void deposit (int date, double amount);  //存入现金 
  void withdraw(int date, double amount) ; //取出现金 
  void settle(int date);
  //显示账户信息
  void show() const;
      
}; 

//account.cpp
#include"account.h" 
#include<cmath>
#include<iostream>
using namespace std;

 double SavingsAccount::total=0;
//SavingAccount 类相关成员函数的实现
SavingsAccount::SavingsAccount(int date, int id, double rate)
: id{id},balance{0},rate{rate},lastDate{date},accumulation{0}{
cout<<date<<"\t#"<<id<<"is created"<<endl;}


 void SavingsAccount::record(int date,double amount){
     accumulation=accumulate(date);
     lastDate=date;
     amount=floor(amount*100+0.5)/100;
     balance+=amount;
     total+=amount;
     cout<<date<<"\t#"<<id<<"\t"<<amount<<"\t"<<balance<<endl;
 }
 
 void SavingsAccount::deposit(int date,double amount){
     record(date,amount);
 }
 
 void SavingsAccount::withdraw(int date,double amount) {
     if(amount>getBalance())
     cout<<"Error:not enough money"<<endl;
     else 
     record(date,-amount);
 }
 void SavingsAccount::settle(int date){
     double interest=accumulate(date) * rate/365;
     if(interest !=0)
       record(date,interest);
       accumulation=0; }
 
 void SavingsAccount::show()const{
 cout<<"#"<<id<<"\tBalance:  "<<balance;
 }
 

//5_11.cpp
#include"account.h"
#include<iostream>
using namespace std;
int main(){
    //
    SavingsAccount sa0(1,21325302,0.015);
    SavingsAccount sa1{1,58320212,0.015};
    //
    sa0.deposit(5,5000);
    sa1.deposit(25,10000);
    sa0.deposit(45,5500);
    sa1.withdraw(60,4000);
    //
    sa0.settle(90);
    sa1.settle(90);
    //
    sa0.show();cout<<endl;
    sa1.show();cout<<endl;
    cout<<"Total:"<<SavingsAccount::getTotal()<<endl;
    return 0;
}

实验一错误

在编程的时候忘记初始化析构函数，多文件编程的时候造成编译器报错但不知道如何找原因，放在单文件的时候报错信息才发现问题。

实验二收获

一：学习了运用sring类的find函数，查找字符 二：学习了如何隐藏密码  三：运用了exit（）函数返回1为异常，返回0为正常

四：运用容器for循环  编程错误：默认形参写了两遍