实验2 类和对象 基础编程1
1，实验任务1
t.cpp
1 // 类T: 实现 2 // 普通函数实现 3 4 #include "t.h" 5 #include <iostream> 6 #include <string> 7 8 using std::cout; 9 using std::endl; 10 using std::string; 11 12 // static成员数据类外初始化 13 const std::string T::doc{"a simple class sample"}; 14 const int T::max_cnt = 999; 15 int T::cnt = 0; 16 17 18 // 对象方法 19 T::T(int x, int y): m1{x}, m2{y} { 20 ++cnt; 21 cout << "T constructor called.\n"; 22 } 23 24 T::T(const T &t): m1{t.m1}, m2{t.m2} { 25 ++cnt; 26 cout << "T copy constructor called.\n"; 27 } 28 29 T::T(T &&t): m1{t.m1}, m2{t.m2} { 30 ++cnt; 31 cout << "T move constructor called.\n"; 32 } 33 34 T::~T() { 35 --cnt; 36 cout << "T destructor called.\n"; 37 } 38 39 void T::adjust(int ratio) { 40 m1 *= ratio; 41 m2 *= ratio; 42 } 43 44 void T::display() const { 45 cout << "(" << m1 << ", " << m2 << ")" ; 46 } 47 48 // 类方法 49 int T::get_cnt() { 50 return cnt; 51 } 52 53 // 友元 54 void func() { 55 T t5(42); 56 t5.m2 = 2049; 57 cout << "t5 = "; t5.display(); cout << endl; 58 }
t.h
1 #pragma once 2 3 #include <string> 4 5 // 类T: 声明 6 class T { 7 // 对象属性、方法 8 public: 9 T(int x = 0, int y = 0); // 普通构造函数 10 T(const T &t); // 复制构造函数 11 T(T &&t); // 移动构造函数 12 ~T(); // 析构函数 13 14 void adjust(int ratio); // 按系数成倍调整数据 15 void display() const; // 以(m1, m2)形式显示T类对象信息 16 17 private: 18 int m1, m2; 19 20 // 类属性、方法 21 public: 22 static int get_cnt(); // 显示当前T类对象总数 23 24 public: 25 static const std::string doc; // 类T的描述信息 26 static const int max_cnt; // 类T对象上限 27 28 private: 29 static int cnt; // 当前T类对象数目 30 31 // 类T友元函数声明 32 friend void func(); 33 }; 34 35 // 普通函数声明 36 void func();
task.cpp
1 #include "t.h" 2 #include <iostream> 3 4 using std::cout; 5 using std::endl; 6 7 void test(); 8 9 int main() { 10 test(); 11 cout << "\nmain: \n"; 12 cout << "T objects'current count: " << T::get_cnt() << endl; 13 } 14 15 void test() { 16 cout << "test class T: \n"; 17 cout << "T info: " << T::doc << endl; 18 cout << "T objects'max count: " << T::max_cnt << endl; 19 cout << "T objects'current count: " << T::get_cnt() << endl << endl; 20 21 22 T t1; 23 cout << "t1 = "; t1.display(); cout << endl; 24 25 T t2(3, 4); 26 cout << "t2 = "; t2.display(); cout << endl; 27 28 T t3(t2); 29 t3.adjust(2); 30 cout << "t3 = "; t3.display(); cout << endl; 31 32 T t4(std::move(t2)); 33 cout << "t3 = "; t4.display(); cout << endl; 34 35 cout << "T objects'current count: " << T::get_cnt() << endl; 36 37 func(); 38 }
问题一:重新编译后不能正确运行
原因是task1.cpp中的test函数以及main函数中调用了func函数，如果类外部不声明func函数，编译器无法识别该函数的定义位置
普通构造函数：T（int x=0,int y=0）
2.实验任务2
Complex.h
1 #pragma once 2 #include <string> 3 4 class Complex { 5 public: 6 static const std::string doc; 7 Complex(double r = 0, double i = 0); 8 Complex(const Complex& c); 9 double get_real() const; 10 double get_imag() const; 11 Complex add(const Complex& c) const; 12 friend Complex add(const Complex& c1, const Complex& c2); 13 friend bool is_equal(const Complex& c1, const Complex& c2); 14 friend bool is_not_equal(const Complex& c1, const Complex& c2); 15 friend double abs(const Complex& c); 16 friend void output(const Complex& c); 17 private: 18 double real; 19 double imag; 20 };
Complex.cpp
1 #include "Complex.h" 2 #include <iostream> 3 #include <cmath> 4 5 const std::string Complex::doc = "a simplified complex class"; 6 7 Complex::Complex(double r, double i) : real{r}, imag{i} {} 8 Complex::Complex(const Complex& c) : real{c.real}, imag{c.imag} {} 9 double Complex::get_real() const { return real; } 10 double Complex::get_imag() const { return imag; } 11 Complex Complex::add(const Complex& c) const { 12 return Complex(real + c.real, imag + c.imag); 13 } 14 Complex add(const Complex& c1, const Complex& c2) { 15 return Complex(c1.real + c2.real, c1.imag + c2.imag); 16 } 17 bool is_equal(const Complex& c1, const Complex& c2) { 18 return c1.real == c2.real && c1.imag == c2.imag; 19 } 20 bool is_not_equal(const Complex& c1, const Complex& c2) { 21 return!(c1.real == c2.real && c1.imag == c2.imag); 22 } 23 double abs(const Complex& c) { 24 return std::sqrt(c.real * c.real + c.imag * c.imag); 25 } 26 void output(const Complex& c) { 27 std::cout << c.real; 28 if (c.imag >= 0) std::cout << "+"; 29 std::cout << c.imag << "i"; 30 }
task2.cpp
1 #include <iostream> 2 #include "Complex.h" 3 4 using std::cout; 5 using std::endl; 6 using std::boolalpha; 7 8 void test() { 9 cout << "类成员测试: " << endl; 10 cout << Complex::doc << endl; 11 12 cout << endl; 13 14 cout << "Complex对象测试: " << endl; 15 Complex c1; 16 Complex c2(3, -4); 17 const Complex c3(3.5); 18 Complex c4(c3); 19 20 cout << "c1 = "; output(c1); cout << endl; 21 cout << "c2 = "; output(c2); cout << endl; 22 cout << "c3 = "; output(c3); cout << endl; 23 cout << "c4 = "; output(c4); cout << endl; 24 cout << "c4.real = " << c4.get_real() << ", c4.imag = " << c4.get_imag() << endl; 25 26 cout << endl; 27 28 cout << "复数运算测试: " << endl; 29 cout << "abs(c2) = " << abs(c2) << endl; 30 c1.add(c2); 31 cout << "c1 += c2, c1 = "; output(c1); cout << endl; 32 cout << boolalpha; 33 cout << "c1 == c2 : " << is_equal(c1, c2) << endl; 34 cout << "c1 != c3 : " << is_not_equal(c1, c3) << endl; 35 c4 = add(c2, c3); 36 cout << "c4 = c2 + c3, c4 = "; output(c4); cout << endl; 37 } 38 39 int main() { 40 test(); 41 }
实验任务3
构造函数：使用了带参数的构造函数来创建对象
访问实部和虚部的接口：c4.real()和c4.imag()用于获取复数对象的实部和虚部
加法运算接口 自加运算接口 相等判断接口 取模运算接口
对比任务2 代码写法不同更加简洁
实验任务4
Fraction.h
1 #pragma once 2 #include <string> 3 4 class Fraction { 5 public: 6 // 类的描述信息 7 static const std::string doc; 8 // 构造函数 9 Fraction(int up = 0, int down = 1); 10 Fraction(const Fraction& f); 11 // 接口函数 12 int get_up() const; 13 int get_down() const; 14 Fraction negative() const; 15 // 友元函数声明 16 friend void output(const Fraction& f); 17 friend Fraction add(const Fraction& f1, const Fraction& f2); 18 friend Fraction sub(const Fraction& f1, const Fraction& f2); 19 friend Fraction mul(const Fraction& f1, const Fraction& f2); 20 friend Fraction div(const Fraction& f1, const Fraction& f2); 21 private: 22 int up; 23 int down; 24 };
Fraction.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(); return 0; }
实验任务5
account.h
1 #include<iostream> 2 3 class SavingsAccount{ 4 private: 5 int id; 6 double balance; 7 double rate; 8 int lastDate; 9 double accumulation; 10 static double total; 11 12 void record(int date,double amount); 13 double accumulate(int date) const{ 14 return accumulation+balance*(date-lastDate); 15 } 16 17 public: 18 SavingsAccount(int date,int id,double rate); 19 int getId() const {return id;} 20 double getBalance() const{return balance;} 21 double getRate() const{return rate;} 22 static double getTotal(){return total;} 23 void deposit(int rate,double amount); 24 void withdraw(int rate,double amount); 25 void settle(int date); 26 void show() const; 27 28 };
account.cpp
#include "account.h" #include<cmath> #include<iostream> using std::cout; using std::endl; 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<<"Erroe: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; }
