实验2 类和对象_基础编程1

实验1

task1.cpp

t.h:
#pragma once

#include <string>

// 类T: 声明
class T {
// 对象属性、方法
public:
    T(int x = 0, int y = 0);   // 普通构造函数
    T(const T &t);  // 复制构造函数
    T(T &&t);       // 移动构造函数
    ~T();           // 析构函数

    void adjust(int ratio);      // 按系数成倍调整数据
    void display() const;           // 以(m1, m2)形式显示T类对象信息

private:
    int m1, m2;

// 类属性、方法
public:
    static int get_cnt();          // 显示当前T类对象总数

public:
    static const std::string doc;       // 类T的描述信息
    static const int max_cnt;           // 类T对象上限

private:
    static int cnt;         // 当前T类对象数目

// 类T友元函数声明
    friend void func();
};

// 普通函数声明
void func();

t.cpp:
// 类T: 实现
// 普通函数实现

#include "t.h"
#include <iostream>
#include <string>

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

// static成员数据类外初始化
const std::string T::doc{"a simple class sample"};
const int T::max_cnt = 999;
int T::cnt = 0;


// 对象方法
T::T(int x, int y): m1{x}, m2{y} { 
    ++cnt; 
    cout << "T constructor called.\n";
} 

T::T(const T &t): m1{t.m1}, m2{t.m2} {
    ++cnt;
    cout << "T copy constructor called.\n";
}

T::T(T &&t): m1{t.m1}, m2{t.m2} {
    ++cnt;
    cout << "T move constructor called.\n";
}    

T::~T() {
    --cnt;
    cout << "T destructor called.\n";
}           

void T::adjust(int ratio) {
    m1 *= ratio;
    m2 *= ratio;
}    

void T::display() const {
    cout << "(" << m1 << ", " << m2 << ")" ;
}     

// 类方法
int T::get_cnt() {
   return cnt;
}

// 友元
void func() {
    T t5(42);
    t5.m2 = 2049;
    cout << "t5 = "; t5.display(); cout << endl;
}

task1.cpp:
#include "t.h"
#include <iostream>

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

void test();

int main() {
    test();
    cout << "\nmain: \n";
    cout << "T objects'current count: " << T::get_cnt() << endl;
}

void test() {
    cout << "test class T: \n";
    cout << "T info: " << T::doc << endl;
    cout << "T objects'max count: " << T::max_cnt << endl;
    cout << "T objects'current count: " << T::get_cnt() << endl << endl;


    T t1;
    cout << "t1 = "; t1.display(); cout << endl;

    T t2(3, 4);
    cout << "t2 = "; t2.display(); cout << endl;

    T t3(t2);
    t3.adjust(2);
    cout << "t3 = "; t3.display(); cout << endl;

    T t4(std::move(t2));
    cout << "t3 = "; t4.display(); cout << endl;

    cout << "T objects'current count: " << T::get_cnt() << endl;

    func();
}

问题1：不能

出错原因可能是类外未声明函数。

问题2：普通构造函数是带有参数的构造函数，允许用户传递参数以自定义对象的初始化。

拷贝构造函数用于从另一个已存在的对象创建新对象。它通常用于复制另一个对象的属性值，而不共享原始对象的数据。

移动构造函数用于从即将销毁的临时对象转移资源到新对象。它通常用于避免不必要的资源复制，并提高性能。

析构函数：当对象的生命周期结束时（例如，对象离开作用域、被删除等），会自动调用析构函数。

问题3：不能正常运行。

 

实验2

task2.cpp

Complex.h:
#pragma once
#include<iostream>
using namespace std;
class  Complex {
public:
    Complex();
    Complex(double a);
    Complex(double a,double b);
    Complex(const Complex &c);
    static string doc;
    const double get_real();
    const double get_imag();
    const void add(const Complex &c);
    friend Complex add(const Complex &a,const Complex &b);
    friend bool is_equal(const Complex &a, const Complex &b);
    friend bool is_not_equal(const Complex &a, const Complex &b);
    friend void output(const Complex &c);
    friend double abs(const Complex &c);
private:
    double real, imag;
};

Complex.cpp:
#include<iostream>
#include"Complex.h"
#include<cmath>
using namespace std;
string Complex::doc = "a simplified Complex class";
Complex::Complex(double a = 0, double b = 0) {
    real = a;
    imag = b;
}
Complex::Complex() {
    real = 0;
    imag = 0;
}
Complex::Complex(double a = 0) {
    real = a;
    imag = 0;
}
const double Complex::get_real() {
    return Complex::real;
}
const double Complex::get_imag(){
    return Complex::imag;
}
Complex::Complex(const Complex &c) {
    real = c.real;
    imag = c.imag;
}
double abs(const Complex& c) {
    double t =pow((c.real * c.real + c.imag * c.imag),0.5);
    return t;
}
void output(const Complex &c) {
    if (c.imag < 0) {
        cout << c.real<< c.imag << "i" << endl;
    }
    else {
        cout << c.real << "+" << c.imag << "i" << endl;
    }
}
bool is_equal(const Complex& a, const Complex& b) {
    if (a.real == b.real && a.imag == b.imag) {
        return true;
    }
    else {
        return false;
    }
}
bool is_not_equal(const Complex & a, const Complex & b) {
    if (a.real == b.real && a.imag == b.imag) {
        return false;
    }
    else {
        return true;
    }
}
Complex add(const Complex& a, const Complex& b) {
    return Complex::Complex(a.real + b.real,a.imag + b.imag);
}
const void Complex::add(const Complex& c) {
    Complex::real += c.real;
    Complex::imag += c.imag;
}

main:
#include"Complex.h"
 #include <iostream>
using std::cout;
using std::endl;
using std::boolalpha;
void test() {
    cout << "类成员测试: " << endl;
    cout << Complex::doc << endl;
    cout << endl;
    cout << "Complex对象测试: " << endl;
    Complex c1;
    Complex c2(3, -4);
    const Complex c3(3.5);
    Complex c4(c3);
    cout << "c1 = "; output(c1); cout << endl;
    cout << "c2 = "; output(c2); cout << endl;
    cout << "c3 = "; output(c3); cout << endl;
    cout << "c4 = "; output(c4); cout << endl;
    cout << "c4.real = " << c4.get_real() << ", c4.imag = " << c4.get_imag()
        << endl;
    cout << endl;
    cout << "复数运算测试: " << endl;
    cout << "abs(c2) = " << abs(c2) << endl;
    c1.add(c2);
    cout << "c1 += c2, c1 = "; output(c1); cout << endl;
    cout << boolalpha;
    cout << "c1 == c2 : " << is_equal(c1, c2) << endl;
    cout << "c1 != c3 : " << is_not_equal(c1, c3) << endl;
    c4 = add(c2, c3);
    cout << "c4 = c2 + c3, c4 = "; output(c4); cout << endl;
}
int main() {
    test();
}

实验3

task3.cpp

 

#include <iostream>
#include <complex>
using std::cout;
using std::endl;
using std::boolalpha;
using std::complex;
void test() {
    cout << "标准库模板类comple测试: " << endl;
    complex<double> c1;
    complex<double> c2(3, -4);
    const complex<double> c3(3.5);
    complex<double> c4(c3);
    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;
    cout << "c3 = " << c3 << endl;
    cout << "c4 = " << c4 << endl;
    cout << "c4.real = " << c4.real() << ", c4.imag = " << c4.imag() <<endl;
    cout << endl;
    cout << "复数运算测试: " << endl;
    cout << "abs(c2) = " << abs(c2) << endl;
    c1 += c2;
    cout << "c1 += c2, c1 = " << c1 << endl;
    cout << boolalpha;
    cout << "c1 == c2 : " << (c1 == c2) << endl;
    cout << "c1 != c3 : " << (c1 != c3) << endl;
    c4 = c2 + c3;
    cout << "c4 = c2 + c3, c4 = " << c4 << endl;
}
int main() {
    test();
}

 对比：标准库中的+运算和输出更为简单。

启发：标准库较实验2写的代码更为简单易懂，更易于操作者理解和使用，而自己写的库由于个人原因，有些代码可能导致多人操作时操作者产生歧义或不理解，而标准库则通俗易懂，一般不会遇到这种情况。

 

实验4

task4.cpp

 

Fraction.h:
#pragma once
#include<iostream>
#include<cmath>
using namespace std;
class Fraction {
public:
    static string doc;
    Fraction(int a);
    Fraction(int a, int b);
    Fraction(const Fraction& f);
    const int get_up();
    const int get_down();
    const Fraction negative();
    friend void output(const Fraction& f);
    friend Fraction add(const Fraction& f1, const Fraction& f2);
    friend Fraction sub(const Fraction& f1, const Fraction& f2);
    friend Fraction mul(const Fraction& f1, const Fraction& f2);
    friend Fraction div(const Fraction& f1, const Fraction& f2);
private:
    int up, down;
};

Fraction.cpp:
#include<iostream>
#include"Fraction.h"
#include<cmath>
using namespace std;
string Fraction::doc = "Fraction 类V0.01版.\n目前仅支持分数对象的构造、输出、加/减/乘/除运算";
Fraction::Fraction(int a) {
    up=a;
    down=1;
}
Fraction::Fraction(int a,int b){
    int i;
    int min;
    if (abs(a) >= abs(b)) {
        min = b;
    }
    else {
        min = b;
    }
    for (i = 1; i <= min; i++) {
        if (a % i == 0 && b % i == 0) {
            a /= i;
            b /= i;
        }
    }
    up = a;
    down = b;
}
const int Fraction::get_up(){
    return up;
}
const int Fraction::get_down(){
    return down;
}
Fraction::Fraction(const Fraction &f){
    up=f.up;
    down=f.down;
}
void output(const Fraction &f){
    if(f.up==0&&f.down!=0){
        cout<<0<<endl;
    }
    else if(f.down==0){
        cout<<"分母不能为0"<<endl;
    }
    else if((f.down<0&&f.up>0)||(f.up<0&&f.down>0)){
        cout<<"-"<<abs(f.up)<<"/"<<abs(f.down)<<endl;
    }
    else if (f.up != 0 && f.down == 1) {
        cout << abs(f.up)<<endl;
    }
    else if (f.up == f.down) {
        cout << 1 << endl;
    }
    else{
        cout<<abs(f.up)<<"/"<<abs(f.down)<<endl;
    }
}
const Fraction Fraction::negative() {
    return Fraction(-up, down);
}
Fraction add(const Fraction& f1, const Fraction& f2) {
    int a, b;
    a = f1.up * f2.down + f1.down * f2.up;
    b = f1.down * f2.down;
    return Fraction(a, b);
}
Fraction sub(const Fraction& f1, const Fraction& f2) {
    int a, b;
    a = f1.up * f2.down-f1.down * f2.up;
    b = f1.down * f2.down;
    return Fraction(a, b);
}
Fraction mul(const Fraction& f1, const Fraction& f2) {
    int a, b;
    a = f1.up * f2.up;
    b = f1.down * f2.down;
    return Fraction(a, b);
}
Fraction div(const Fraction& f1, const Fraction& f2) {
    int a, b;
    a = f1.up * f2.down;
    b = f1.down * f2.up;
    return Fraction(a, b);
}

task4.cpp：
#include "Fraction.h"
#include <iostream>
using std::cout;
using std::endl;
void test1() {
    cout << "Fraction类测试: " << endl;
    cout << Fraction::doc << endl << endl;
    Fraction f1(5);
    Fraction f2(3, -4), f3(-18, 12);
    Fraction f4(f3);
    cout << "f1 = "; output(f1); cout << endl;
    cout << "f2 = "; output(f2); cout << endl;
    cout << "f3 = "; output(f3); cout << endl;
    cout << "f4 = "; output(f4); cout << endl;
    Fraction f5(f4.negative());
        cout << "f5 = "; output(f5); cout << endl;
    cout << "f5.get_up() = " << f5.get_up() << ", f5.get_down() = " << f5.get_down() << endl;
    cout << "f1 + f2 = "; output(add(f1, f2)); cout << endl;
    cout << "f1 - f2 = "; output(sub(f1, f2)); cout << endl;
    cout << "f1 * f2 = "; output(mul(f1, f2)); cout << endl;
    cout << "f1 / f2 = "; output(div(f1, f2)); cout << endl;
    cout << "f4 + f5 = "; output(add(f4, f5)); cout << endl;
}
void test2() {
    Fraction f6(42, 55), f7(0, 3);
    cout << "f6 = "; output(f6); cout << endl;
    cout << "f7 = "; output(f7); cout << endl;
    cout << "f6 / f7 = "; output(div(f6, f7)); cout << endl;
}
int main() {
    cout << "测试1: Fraction类基础功能测试\n";
    test1();
    cout << "\n测试2: 分母为0测试: \n";
    test2();
}

 

实验5

task5.cpp

account.h:
#pragma once
class SavingAccount {
private:
    int id;
    double balance;
    double rate;
    int lastDate;
    double accumulation;
    static double total;
    void record(int date, double amout);
    double accumulate(int date)const {
        return accumulation + balance * (date - lastDate);

    }
public:
    SavingAccount(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);
    void withdraw(int date, double amount);
    void settle(int date);
    void show() const;
};


account.cpp:
#include"account.h"
#include<cmath>
#include<iostream>
using namespace std;
double SavingAccount::total = 0;
SavingAccount::SavingAccount(int date, int id, double rate) :
    id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
    cout << date << "\t#" << id << "is created" << endl;
}
void SavingAccount::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 SavingAccount::deposit(int date, double amount) {
    record(date, amount);

}
void SavingAccount::withdraw(int date, double amount) {
    if (amount > getBalance())
        cout << "Error:not enough money" << endl;
    else
        record(date, -amount);

}
void SavingAccount::settle(int date) {
    double interest = accumulate(date) * rate / 365;
    if (interest != 0)
        record(date, interest);
    accumulation = 0;
}
void SavingAccount::show()const {
    cout << "#" << id << "\tBalance:" << balance;
}


5_11.cpp:
#include"account.h"
#include<iostream>
using namespace std;
int main(){
    SavingAccount sa0(1, 21325302, 0.015);
    SavingAccount 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:" << SavingAccount::getTotal() << endl;
    return 0;

}

 思考：该程序基本功能较为完善，能执行简单的银行账户管理操作，就是输出结果不够直观，可以增加使输出结果更为直观明了的代码来进行完善，否则可能会造成使用者看不懂输出结果的现象。