任务1:
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1:t.h 中不能去掉line36
原因:友元函数要通过相应的类或对象名来访问,直接访问会使编译器找不到声明。
问题2:t.h中
line 9 :普通构造函数,在对象被创建时利用特定的值构造对象,将对象初始化为一个特殊的状态。 调用时机:在对象被创建时自动调用。
line10:复制构造函数:使用一个已经存在的对象,去初始化同类的一个新对象 调用时机:当用类的一个对象去初始化该类的另一个对象时;如果函数的形参是类的对象,调用函数时,进行形参和实参结合时;如果函数的返回值是类的对象,函数执行完成返回调用者时。
line11:通过引用已有对象来安全地构造新对象。调用时机:当引用对象用于构造新对象时。
line12:析构函数:用来完成对象被删除前的清理工作,释放相应内存空间。调用时机:在对象的生存期即将结束的时候。
问题3:不能。
任务2:
Complex.h
#include <stdlib.h> #include <string> #include <cmath> using namespace std; class Complex { public: Complex(); Complex(double r, double i); Complex(double r); Complex(const Complex& c); static const string doc; double const get_real(); double const get_imag(); void add(const Complex& c); 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 void output(Complex c); friend double abs(Complex c); private: double real; double imag; };
Complex.cpp
#include "Complex.h" #include<iostream> using namespace std; const string Complex::doc{ "a simplified Complex calss" }; Complex::Complex(double r, double i) { real = r; imag = i; } Complex::Complex(double r) { real = r; imag = 0; } Complex::Complex() { real = 0; imag = 0; } Complex::Complex(const Complex& c) { real = c.real; imag = c.imag; } double const Complex::get_real() { return real; } double const Complex::get_imag() { return imag; } void Complex::add(const Complex& c) { real += c.real; imag += c.imag; } Complex add(const Complex& c1, const Complex& c2) { Complex s; s.real += c1.real + c2.real; s.imag += c1.imag + c2.imag; return s; } bool is_equal(const Complex& c1, const Complex& c2) { if (c1.real == c2.real && c1.imag == c2.imag) return true; else return false; } bool is_not_equal(const Complex& c1, const Complex& c2) { if (c1.real == c2.real && c1.imag == c2.imag) return false; else return true; } void output(Complex c) { cout << c.real; if (c.imag < 0) cout << " - " << -c.imag << 'i' << endl; else cout << " + " << c.imag << 'i' << endl; } double abs(Complex c) { return sqrt(c.real * c.real + c.imag * c.imag); }
test.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(); }
任务3:
#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(); }
标准模板库的complex类使用十分简洁,清晰,各种运算也十分方便
任务4
Fraction.h
#pragma once #include<iostream> #include<string> using namespace std; class Fraction { public: Fraction(); Fraction(int a); Fraction(int a, int b); Fraction(const Fraction& f); static const string doc; private: int up, down; public: int get_up()const; int get_down()const; Fraction negative(); friend void output(Fraction f); friend Fraction add(Fraction f1, Fraction f2); friend Fraction sub(Fraction f1, Fraction f2); friend Fraction mul(Fraction f1, Fraction f2); friend Fraction div(Fraction f1, Fraction f2); };
Fraction.cpp
#include"Fraction.h" using namespace std; const string Fraction::doc{ "Fraction类 v 0.01版. 目前仅支持分数对象的构造、输出、加 / 减 / 乘 / 除运算." }; int gcd(int x, int y) { if (x == 0 || y == 0) { return x ? y == 0 : y; } if (x % y == 0) return y; else return gcd(y, x % y); } Fraction::Fraction() { up = 1; down = 1; } Fraction::Fraction(int a) { up = a; down = 1; } Fraction::Fraction(int a, int b) { up=a/gcd(a, b); down = b / gcd(a, b); } Fraction::Fraction(const Fraction& f) { up = f.up; down = f.down; } int Fraction::get_up()const { return up; } int Fraction::get_down()const { return down; } Fraction Fraction::negative() { Fraction f3; f3.up = -up; f3.down = down; return f3; } void output(Fraction f) { if (f.down == 0) cout << "分母不能为0" << endl; else if (f.up == 0) { cout << "0" << endl; } else if (f.down == 1)cout << f.up << endl; else if (f.down == -1) cout << -f.up << endl; else if (f.down<0) cout <<- f.up << "/" << -f.down << endl; else cout << f.up << "/" << f.down << endl; } Fraction add(Fraction f1, Fraction f2) { return Fraction(f1.up * f2.down + f2.up * f1.down, f1.down * f2.down); } Fraction sub(Fraction f1, Fraction f2) { return Fraction(f1.up * f2.down-f2.up*f1.down, f1.down * f2.down); } Fraction mul(Fraction f1, Fraction f2) { return Fraction(f1.up * f2.up, f1.down * f2.down); } Fraction div(Fraction f1, Fraction f2) { return Fraction(f1.up * f2.down, f1.down * f2.up); }
test.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(); }
任务5:
account.h
#pragma once 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; };
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; }
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; }
标签:const,对象,double,编程,int,Complex,实验,Fraction,include From: https://www.cnblogs.com/bearrrr/p/18494374