实验一:
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(); }
实验结果:
问题一:
task.cpp调用了func函数,却没有在t.h中声明这个func函数
问题二:
普通构造函数是用给定的参数初始化,在创建对象时被调用;复制构造函数是用一个已存在的对象来初始化一个新对象;移动构造函数:用一个临时对象初始化新创立的对象;析构函数:在对象生命周期结束时,或者动态分配对象被delete调用时。
问题三:
不能正常运行。
实验二:
Complex.h
#pragma once #include <string> class Complex { public: static const std::string doc; Complex(double r = 0, double i = 0); Complex(const Complex& c); double get_real() const; double get_imag() const; Complex add(const Complex& c) const; friend Complex add(const Complex& c1, const Complex& c2); friend bool is_equal(const Complex& c1, const Complex& c2); friend bool is_not_equal(const Complex& c1, const Complex& c2); friend double abs(const Complex& c); friend void output(const Complex& c); private: double real; double imag; };
Complex.cpp
#include "Complex.h" #include <iostream> #include <cmath> const std::string Complex::doc{"a simplified complex class"}; Complex::Complex(double r, double i) : real{r}, imag{i} {} Complex::Complex(const Complex& c) : real{c.real}, imag{c.imag} {} double Complex::get_real() const { return real; } double Complex::get_imag() const { return imag; } Complex Complex::add(const Complex& c) const { return Complex(real + c.real, imag + c.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) { return c1.real == c2.real && c1.imag == c2.imag; } bool is_not_equal(const Complex& c1, const Complex& c2) { return!(c1.real == c2.real && c1.imag == c2.imag); } double abs(const Complex& c) { return std::sqrt(c.real * c.real + c.imag * c.imag); } void output(const Complex& c) { std::cout << c.real; if (c.imag >= 0) { std::cout << "+"; } std::cout << c.imag << "i"; }
main.cpp
#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(); }
实验结果
实验三
#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(); }
实验结果
启示
构造函数和操作符重载的使用使得代码直观而在使用标准库complex模板类时,可以直接使用+操作符标准库模板类的设计考虑了复数的常见需求,提供了简洁、高效的接口。在设计自定义类时,可以参考标准库的设计模式,更好地满足用户需求并提高代码的可读性和可维护性。
实验四
Fraction.cpp
#include "Fraction.h" #include <iostream> #include <string> using std::cout; using std::endl; using std::string; const string Fraction::doc {"Fraction类 v 0.01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 u, int d): up{u}, down{d} { } Fraction::Fraction(const Fraction& other): up{other.up}, down{other.down} {} Fraction::~Fraction() {} int Fraction::get_up() const{ int a = up, b = down; int u = up, d = down; while (b != 0) { int temp = b; b = a % b; a = temp; } int gcd = a; u /= gcd; d /= gcd; if (d < 0) { d = -d; u = -u; } return u; } int Fraction::get_down() const{ int a = up, b = down; int u = up, d = down; while (b != 0) { int temp = b; b = a % b; a = temp; } int gcd = a; u /= gcd; d /= gcd; if (d < 0) { d = -d; u = -u; } return d; } Fraction Fraction::negative() const{ return Fraction(-up, down); } void output(const Fraction &f) { if(f.down == 0) { cout << "分母不能为0"; return; } int a = f.up, b = f.down; int u = f.up, d = f.down; while (b != 0) { int temp = b; b = a % b; a = temp; } int gcd = a; u /= gcd; d /= gcd; if (d < 0) { d = -d; u = -u; } if(u == 0) cout << 0; else if(d == 1) cout << u; else cout << u << "/" << d ; } Fraction add(const Fraction& f1, const Fraction& f2) { return Fraction(f1.up * f2.down + f2.up * f1.down, f1.down * f2.down); } Fraction sub(const Fraction& f1, const Fraction& f2) { return Fraction(f1.up * f2.down - f2.up * f1.down, f1.down * f2.down); } Fraction mul(const Fraction& f1, const Fraction& f2) { return Fraction(f1.up * f2.up, f1.down * f2.down); } Fraction div(const Fraction& f1, const Fraction& f2) { return Fraction(f1.up * f2.down, f1.down * f2.up); }
Fraction.h
#pragma once #include <string> using std::string; class Fraction { private: int up, down; public: static const string doc; Fraction(int u, int d = 1); Fraction(const Fraction &other); ~Fraction(); int get_up() const; int get_down() const; Fraction negative() const; 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); };
test.cpp
#include "C:\Users\DELL\Desktop\新建文件夹\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(); }
实验结果
实验五
main.cpp
#include "C:\Users\DELL\Desktop\新建文件夹\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; }
account.cpp
#include "account.h" #include <cmath> #include <iostream> using namespace std; double SavingsAccount::total = 0; 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; }
account.h
#ifndef __ACCOUNT_H__ #define __ACCOUNT_H__ class SavingsAccount { private: int id; double balance; double rate; int lastDate; double accumulation; static double total; void record(int date, double amount); double accumulate(int date) const { return accumulation + balance * (date - lastDate); } public: 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); void withdraw(int date, double amount); void settle(int date); void show() const; }; #endif
实验结果
数据的安全性和一些关键步骤,比如存取款剩余不足等
改进接口,减少用户的操作复杂度,加强对输入数据的合法性与安全性的验证
标签:std,const,对象,double,编程,int,Complex,实验,Fraction From: https://www.cnblogs.com/hinaou/p/18494308