实验二 类和对象
任务1
代码:
t.h:
1 #pragma once 2 #include<string> 3 4 class T { 5 public: 6 T(int x = 0, int y = 0); 7 T(const T& t); 8 T(T&& t); 9 ~T(); 10 void adjust(int ratio); 11 void display()const; 12 private: 13 int m1, m2; 14 15 public: 16 static int get_cnt(); 17 18 public: 19 static const std::string doc; 20 static const int max_cnt; 21 22 private: 23 static int cnt; 24 friend void func(); 25 }; 26 27 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:
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 }
运行截图:
问题1:不能, 原因可能是没有声明函数。
问题2:普通构造函数实现了对类的初始化,复制构造函数主要用于初始化一个新的对象,使其成为另一个同类型对象的副本,它会将引用的源对象的值复制到新对象中。移动构造函数的作用是提高程序的效率,其通过右值引用创建新对象,它避免了深拷贝,直接转移原始对象的资源到新对象中,从而减少了复制的时间。析构函数作用是在对象生命周期结束时进行资源清理。当前三种构造函数全部结束时析构函数会自动调用多遍。
问题3:不能正确编译。
任务2
代码:
Complex.h:
1 class Complex{ 2 3 public: 4 static string doc; 5 Complex(double r=0,double i=0); 6 Complex(const Complex &c); 7 double get_real(); 8 double get_imag(); 9 void add(Complex &c); 10 friend Complex add(const Complex &c1,const Complex &c2); 11 friend bool is_equal(const Complex &c1,const Complex &c2); 12 friend bool is_not_equal(const Complex &c1,const Complex &c2); 13 friend void output(const Complex &c1); 14 friend double abs(const Complex &c1); 15 private: 16 double real; 17 double imag; 18 19 }; 20 21 #endif
Complex.cpp:
1 #include <bits/stdc++.h> 2 #include "Complex.h" 3 using namespace std; 4 5 string Complex::doc="a simplified complex class"; 6 Complex::Complex(double r,double i):real{r},imag{i}{} 7 Complex::Complex(const Complex &c):real{c.real},imag{c.imag}{} 8 double Complex::get_real(){return real;} 9 double Complex::get_imag(){return imag;} 10 void Complex::add(Complex &c){ 11 real+=c.real; 12 imag+=c.imag; 13 } 14 Complex add(const Complex &c1,const Complex &c2) 15 { 16 Complex c3; 17 c3.real=c1.real+c2.real; 18 c3.imag=c1.imag+c2.imag; 19 return c3; 20 } 21 22 bool is_equal(const Complex &c1,const Complex &c2) 23 { 24 if(c1.real==c2.real&&c1.imag==c2.imag) 25 return true; 26 return false; 27 } 28 29 bool is_not_equal(const Complex &c1,const Complex &c2) 30 { 31 if(c1.real==c2.real&&c1.imag==c2.imag) 32 return false; 33 return true; 34 } 35 36 void output(const Complex &c1) 37 { 38 cout<<c1.real<<" + "<<c1.imag<<"i"<<endl; 39 } 40 41 double abs(const Complex &c1) 42 { 43 return sqrt(c1.real*c1.real+c1.imag*c1.imag); 44 }
task2.cpp:
1 #include "Complex.h" 2 #include <iostream> 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 }
运行截图:
任务3
代码:
1 #include <iostream> 2 #include <complex> 3 4 using std::cout; 5 using std::endl; 6 using std::boolalpha; 7 using std::complex; 8 9 void test() { 10 cout << "标准库模板类comple测试: " << endl; 11 complex<double> c1; 12 complex<double> c2(3, -4); 13 const complex<double> c3(3.5); 14 complex<double> c4(c3); 15 16 cout << "c1 = " << c1 << endl; 17 cout << "c2 = " << c2 << endl; 18 cout << "c3 = " << c3 << endl; 19 cout << "c4 = " << c4 << endl; 20 cout << "c4.real = " << c4.real() << ", c4.imag = " << c4.imag() << endl; 21 cout << endl; 22 23 cout << "复数运算测试: " << endl; 24 cout << "abs(c2) = " << abs(c2) << endl; 25 c1 += c2; 26 cout << "c1 += c2, c1 = " << c1 << endl; 27 cout << boolalpha; 28 cout << "c1 == c2 : " << (c1 == c2) << endl; 29 cout << "c1 != c3 : " << (c1 != c3) << endl; 30 c4 = c2 + c3; 31 cout << "c4 = c2 + c3, c4 = " << c4 << endl; 32 } 33 34 int main() { 35 test(); 36 }
运行截图:
任务4
代码:
Fraction.h:
View Code
1 #pragma once 2 #include<string> 3 4 class Fraction{ 5 private: 6 int up; 7 int down; 8 9 public: 10 Fraction(int u,int d=1); 11 Fraction(const Fraction &f); 12 13 static const std::string doc; 14 int get_up(); 15 int get_down(); 16 Fraction negative(); 17 friend void output(const Fraction f); 18 friend Fraction add(const Fraction f1,const Fraction f2); 19 friend Fraction sub(const Fraction f1,const Fraction f2); 20 friend Fraction mul(const Fraction f1,const Fraction f2); 21 friend Fraction div(const Fraction f1,const Fraction f2); 22 }; 23 void output(const Fraction f); 24 Fraction add(const Fraction f1,const Fraction f2); 25 Fraction sub(const Fraction f1,const Fraction f2); 26 Fraction mul(const Fraction f1,const Fraction f2); 27 Fraction div(const Fraction f1,const Fraction f2);
Fraction.cpp:
View Code
1 #include <bits/stdc++.h> 2 #include "Fraction.h" 3 using namespace std; 4 5 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.\n"; 6 Fraction::Fraction(int u,int d):up{u},down{d}{} 7 Fraction::Fraction(const Fraction &f):up{f.up},down{f.down}{} 8 int Fraction::get_up() 9 { 10 int a,b; 11 a=abs(up);b=abs(down); 12 13 while (b) 14 { 15 int tmp=a; 16 a=b; 17 b=tmp%b; 18 } 19 return up/a; 20 } 21 int Fraction::get_down() 22 { 23 int a,b; 24 a=abs(up);b=abs(down); 25 26 while (b) 27 { 28 int tmp=a; 29 a=b; 30 b=tmp%b; 31 } 32 return down/a; 33 } 34 Fraction Fraction::negative() 35 { 36 int new_up=-up; 37 Fraction f(new_up,down); 38 return f; 39 } 40 41 void output(const Fraction f) 42 { 43 if (f.down==0) 44 { 45 cout<<"分母不能为0"; 46 return ; 47 } 48 49 int a,b; 50 a=abs(f.up);b=abs(f.down); 51 52 while (b) 53 { 54 int tmp=a; 55 a=b; 56 b=tmp%b; 57 } 58 int new_down=f.down/a; 59 if (new_down==1) 60 cout<<f.up/a; 61 else if (f.up*f.down>0) 62 cout<<abs(f.up)/a<<"/"<<abs(f.down)/a; 63 else 64 cout<<"-"<<abs(f.up)/a<<"/"<<abs(f.down)/a; 65 } 66 67 Fraction add(const Fraction f1,const Fraction f2) 68 { 69 int new_down=f1.down*f2.down; 70 int new_up=f1.up*f2.down+f2.up*f1.down; 71 int a,b; 72 a=abs(new_up);b=abs(new_down); 73 while (b) 74 { 75 int tmp=a; 76 a=b; 77 b=tmp%b; 78 } 79 new_up/=a;new_down/=a; 80 Fraction f(new_up,new_down); 81 return f; 82 } 83 84 Fraction sub(Fraction f1,Fraction f2) 85 { 86 int new_down=f1.down*f2.down; 87 int new_up=f1.up*f2.down-f2.up*f1.down; 88 int a,b; 89 a=abs(new_up);b=abs(new_down); 90 while (b) 91 { 92 int tmp=a; 93 a=b; 94 b=tmp%b; 95 } 96 new_up/=a;new_down/=a; 97 Fraction f(new_up,new_down); 98 return f; 99 } 100 101 Fraction mul(Fraction f1,Fraction f2) 102 { 103 int new_up=f1.up*f2.up; 104 int new_down=f1.down*f2.down; 105 int a,b; 106 a=abs(new_up);b=abs(new_down); 107 while (b) 108 { 109 int tmp=a; 110 a=b; 111 b=tmp%b; 112 } 113 new_up/=a;new_down/=a; 114 Fraction f(new_up,new_down); 115 return f; 116 } 117 118 Fraction div(Fraction f1,Fraction f2) 119 { 120 121 int new_up=f1.up*f2.down; 122 int new_down=f1.down*f2.up; 123 int a,b; 124 a=abs(new_up);b=abs(new_down); 125 while (b) 126 { 127 int tmp=a; 128 a=b; 129 b=tmp%b; 130 } 131 new_up/=a;new_down/=a; 132 Fraction f(new_up,new_down); 133 return f; 134 }
task4.cpp:
1 #include "Fraction.h" 2 #include <iostream> 3 4 using std::cout; 5 using std::endl; 6 7 8 void test1() { 9 cout << "Fraction类测试: " << endl; 10 cout << Fraction::doc << endl << endl; 11 12 Fraction f1(5); 13 Fraction f2(3, -4), f3(-18, 12); 14 Fraction f4(f3); 15 cout << "f1 = "; output(f1); cout << endl; 16 cout << "f2 = "; output(f2); cout << endl; 17 cout << "f3 = "; output(f3); cout << endl; 18 cout << "f4 = "; output(f4); cout << endl; 19 20 Fraction f5(f4.negative()); 21 cout << "f5 = "; output(f5); cout << endl; 22 cout << "f5.get_up() = " << f5.get_up() << ", f5.get_down() = " << f5.get_down() << endl; 23 24 cout << "f1 + f2 = "; output(add(f1, f2)); cout << endl; 25 cout << "f1 - f2 = "; output(sub(f1, f2)); cout << endl; 26 cout << "f1 * f2 = "; output(mul(f1, f2)); cout << endl; 27 cout << "f1 / f2 = "; output(div(f1, f2)); cout << endl; 28 cout << "f4 + f5 = "; output(add(f4, f5)); cout << endl; 29 } 30 31 void test2() { 32 Fraction f6(42, 55), f7(0, 3); 33 cout << "f6 = "; output(f6); cout << endl; 34 cout << "f7 = "; output(f7); cout << endl; 35 cout << "f6 / f7 = "; output(div(f6, f7)); cout << endl; 36 } 37 38 int main() { 39 cout << "测试1: Fraction类基础功能测试\n"; 40 test1(); 41 42 cout << "\n测试2: 分母为0测试: \n"; 43 test2(); 44 }
运行截图:
任务5
代码:
account.h:
View Code
1 #ifndef __ACCOUNT_H__ 2 #define __ACCOUNT_H__ 3 4 class SavingAccount{ 5 private: 6 int id; 7 double balance; 8 double rate; 9 double lastData; 10 double accumulation; 11 12 static double total; 13 14 void record(int data,double amount); 15 double accumulate(int data) const 16 { 17 return accumulation+balance*(data-lastData); 18 } 19 public: 20 SavingAccount(int data,int id,double rate); 21 int getId() const {return id;} 22 double getBalance() const {return balance;} 23 double getRate() const {return rate;} 24 static double getTotal() {return total;} 25 void deposit(int data,double amount); 26 void withdraw(int data,double amount); 27 void settle(int data); 28 void show() const; 29 }; 30 #endif
account.cpp:
View Code
1 #include <bits/stdc++.h> 2 #include "account.h" 3 using namespace std; 4 5 double SavingAccount::total=0; 6 SavingAccount::SavingAccount(int data,int id,double rate) 7 :id(id),balance(0),rate(rate),lastData(data),accumulation(0) 8 { 9 cout<<data<<"\t#"<<id<<"is created"<<endl; 10 } 11 12 void SavingAccount::record(int data,double amount) 13 { 14 accumulation=accumulate(data); 15 lastData=data; 16 amount=floor(amount*100+0.5)/100; 17 balance+=amount; 18 total+=amount; 19 cout<<data<<"\t#"<<id<<"\t"<<amount<<"\t"<<balance<<endl; 20 } 21 22 void SavingAccount::deposit(int data,double amount) 23 { 24 record(data,amount); 25 } 26 27 void SavingAccount::withdraw(int data,double amount) 28 { 29 if (amount>getBalance()) 30 cout<<"Error:not enough money"<<endl; 31 else 32 record(data,-amount); 33 } 34 35 void SavingAccount::settle(int data) 36 { 37 double interest=accumulate(data)*rate/365; 38 if (interest!=0) 39 record(data,interest); 40 accumulation=0; 41 } 42 void SavingAccount::show() const 43 { 44 cout<<"#"<<id<<"\tBalance:"<<balance; 45 }
5_11.cpp:
View Code
1 #include "account.h" 2 #include <iostream> 3 using namespace std; 4 5 int main () 6 { 7 SavingAccount sa0(1,21325302,0.015); 8 SavingAccount sa1(1,58320212,0.015); 9 10 sa0.deposit(5,5000); 11 sa1.deposit(25,10000); 12 sa0.deposit(45,5500); 13 sa1.deposit(60,4000); 14 15 sa0.settle(90); 16 sa1.settle(90); 17 18 sa0.show();cout<<endl; 19 sa1.show();cout<<endl; 20 cout<<"Total:"<<SavingAccount::getTotal()<<endl; 21 return 0; 22 }
运行截图:
好难