实验2 类和对象_基础编程1

1.实验任务1

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();

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 }

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 }

运行结果截图：

问题1：

不能正常运行；

原因：友元函数func只在类当中声明，主函数找不到此函数。

问题2：

普通构造函数：用于初始化对象，在创建对象时调用

复制构造函数：通过复制已经存在的对象来初始化新对象，当对象复制时调用

移动构造函数：通过已存在对象的属性来初始化对象，当对象移动时调用

析构函数：清理对象，对象生命周期结束时被调用

问题3：

不能正确编译运行

实验任务2：

Complex.h

 1 #pragma once
 2 #include<string>
 3 using namespace std;
 4 class Complex{
 5     private:
 6         double real;
 7         double imag;
 8     public:
 9         static const string doc;
10         Complex(double r=0,double i=0);
11         Complex(const Complex &c);
12         double get_real()const;
13         double get_imag()const;
14         void add(const Complex &c);
15         //友元函数声明 
16         friend Complex add(const Complex &c1,const Complex &c2);
17         friend bool is_equal(const Complex &c1,const Complex &c2);
18         friend bool is_not_equal(const Complex &c1,const Complex &c2);
19         friend double abs(const Complex &c);
20         friend void output(const Complex &c);
21 };
22 //友元函数类外声明 
23 Complex add(const Complex &c1,const Complex &c2);
24 bool is_equal(const Complex &c1,const Complex &c2);
25 bool is_not_equal(const Complex &c1,const Complex &c2);
26 double abs(const Complex &c);
27 void output(const Complex &c);

Complex.cpp

 1 #include"Complex.h"
 2 #include<iostream>
 3 #include<string>
 4 #include<math.h>
 5 using namespace std;
 6 
 7 const string Complex::doc{"a simplified Complex class"};
 8 
 9 Complex::Complex(double r,double i):real{r},imag{i}{
10 }
11 Complex::Complex(const Complex &c):real{c.real},imag{c.imag}{
12 }
13 double Complex::get_real()const{
14     return real;
15 }
16 double Complex::get_imag()const{
17     return imag;
18 }
19 void Complex::add(const Complex &c){
20     real+=c.real;
21     imag+=c.imag;
22 
23 }
24 Complex add(const Complex &c1,const Complex &c2){
25     Complex c3;
26     c3.real = c1.real + c2.real;
27     c3.imag = c1.imag + c2.imag;
28     return c3;
29 }
30 bool is_equal(const Complex &c1,const Complex &c2){
31     if(c1.real==c2.real&&c1.imag==c2.imag)
32         return true;   
33     else return false;
34 }
35 bool is_not_equal(const Complex &c1,const Complex &c2){
36     if(c1.real==c2.real&&c1.imag==c2.imag)
37         return false;    
38     else   return true;
39 }
40 void output(const Complex &c){
41     if(c.imag>=0)
42     cout<<c.real<<"+"<<c.imag<<"i";
43     else
44     cout<<c.real<<c.imag<<"i";
45 }
46 double abs(const Complex &c){
47     return  sqrt(c.real*c.real + c.imag + c.imag);    
48 }

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 }

运行结果截图：

实验任务3：

task3.cpp

 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 }

运行结果截图：

使用的接口：成员函数c.real、c.imag,abs(),c1+=c2,c4=c2+c3,c1==c2,c1!=c3.

对比q1：可以调用real()和imag（）成员函数，直接访问复数的实部和虚部，无需定义get函数。

可以直接使用cout进行输出，无需定义输出函数

构造函数更简单

实验任务4：

Fraction.h

 1 #pragma once
 2 #include <string>
 3 
 4 using std::string;
 5 
 6 class Fraction {
 7 private:
 8     int up, down;
 9 
10 public:
11     static const string doc;
12     Fraction(int u, int d = 1);
13     Fraction(const Fraction &other);
14     ~Fraction();
15 
16     int get_up() const;
17     int get_down() const;
18     Fraction negative() const;
19     //友元函数声明 
20     friend void output(const Fraction &f);
21     friend Fraction add(const Fraction &f1, const Fraction &f2);
22     friend Fraction sub(const Fraction &f1, const Fraction &f2);
23     friend Fraction mul(const Fraction &f1, const Fraction &f2);
24     friend Fraction div(const Fraction &f1, const Fraction &f2);
25 };
26     void output(const Fraction &f);
27     Fraction add(const Fraction &f1, const Fraction &f2);
28     Fraction sub(const Fraction &f1, const Fraction &f2);
29     Fraction mul(const Fraction &f1, const Fraction &f2);
30     Fraction div(const Fraction &f1, const Fraction &f2);

Fraction.cpp

 1 #include "Fraction.h"
 2 #include <iostream>
 3 #include <string>
 4 
 5 using namespace std; 
 6 
 7 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."};
 8 
 9 Fraction::Fraction(int u, int d): up{u}, down{d} {
10 }
11 
12 Fraction::Fraction(const Fraction& other): up{other.up}, down{other.down} {}
13 
14 Fraction::~Fraction() {}
15 
16 int Fraction::get_up() const{
17     int a = up, b = down;
18     int u = up, d = down;
19     while (b != 0) {
20         int temp = b;
21         b = a % b;
22         a = temp;
23     }
24     int gcd = a;
25     u /= gcd;
26     d /= gcd;
27     if (d < 0) {
28         d = -d;
29         u = -u;
30     }
31     return u;
32 }
33 
34 int Fraction::get_down() const{
35     int a = up, b = down;
36     int u = up, d = down;
37     while (b != 0) {
38         int temp = b;
39         b = a % b;
40         a = temp;
41     }
42     int gcd = a;
43     u /= gcd;
44     d /= gcd;
45     if (d < 0) {
46         d = -d;
47         u = -u;
48     }
49     return d;
50 }
51 
52 Fraction Fraction::negative() const{
53     return Fraction(-up, down);
54 }
55 
56 void output(const Fraction &f) {
57     if(f.down == 0) {
58         cout << "分母不能为0";
59         return;
60     }
61 
62     int a = f.up, b = f.down;
63     int u = f.up, d = f.down;
64     while (b != 0) {
65         int temp = b;
66         b = a % b;
67         a = temp;
68     }
69     int gcd = a;
70     u /= gcd;
71     d /= gcd;
72     if (d < 0) {
73         d = -d;
74         u = -u;
75     }
76     if(u == 0)
77         cout << 0;
78     else if(d == 1)
79         cout << u;
80     else
81         cout << u << "/" << d ;
82 }
83 
84 Fraction add(const Fraction& f1, const Fraction& f2) {
85     return Fraction(f1.up * f2.down + f2.up * f1.down, f1.down * f2.down);
86 }
87 
88 Fraction sub(const Fraction& f1, const Fraction& f2) {
89     return Fraction(f1.up * f2.down - f2.up * f1.down, f1.down * f2.down);
90 }
91 
92 Fraction mul(const Fraction& f1, const Fraction& f2) {
93     return Fraction(f1.up * f2.up, f1.down * f2.down);
94 }
95 
96 Fraction div(const Fraction& f1, const Fraction& f2) {
97     return Fraction(f1.up * f2.down, f1.down * f2.up);
98 }

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 }

运行结果截图：

实验任务5：

account.h

 1 #ifndef __ACCOUNT_H__
 2 #define __ACCOUNT_H__
 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   
14     double accumulate(int date) const {
15         return accumulation + balance * (date - lastDate);
16     }
17 public:
18    
19     SavingsAccount(int date, int id, double rate);
20     int getId() const { return id; }
21     double getBalance() const { return balance; }
22     double getRate() const { return rate; }
23     static double getTotal() { return total; }
24     void deposit(int date, double amount);         
25     void withdraw(int date, double amount);     
26     
27     void settle(int date);
28    
29     void show() const;
30 };
31 #endif

account.cpp

 1 #include "account.h"
 2 #include <cmath>
 3 #include <iostream>
 4 using namespace std;
 5 
 6 double SavingsAccount::total = 0;
 7 
 8 SavingsAccount::SavingsAccount(int date, int id, double rate)
 9         : id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
10     cout << date << "\t#" << id << " is created" << endl;
11 }
12 void SavingsAccount::record(int date, double amount) {
13     accumulation = accumulate(date);
14     lastDate = date;
15     amount = floor(amount * 100 + 0.5) / 100;    
16     balance += amount;
17     total += amount;
18     cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl;
19 }
20 void SavingsAccount::deposit(int date, double amount) {
21     record(date, amount);
22 }
23 void SavingsAccount::withdraw(int date, double amount) {
24     if (amount > getBalance())
25         cout << "Error: not enough money" << endl;
26     else
27         record(date, -amount);
28 }
29 void SavingsAccount::settle(int date) {
30     double interest = accumulate(date) * rate / 365;    
31     if (interest != 0)
32         record(date, interest);
33     accumulation = 0;
34 }
35 void SavingsAccount::show() const {
36     cout << "#" << id << "\tBalance: " << balance;
37 }

task5.cpp

 1 #include "account.h"
 2 #include <iostream>
 3 using namespace std;
 4 int main() {
 5 
 6     SavingsAccount sa0(1, 21325302, 0.015);
 7     SavingsAccount sa1(1, 58320212, 0.015);
 8   
 9     sa0.deposit(5, 5000);
10     sa1.deposit(25, 10000);
11     sa0.deposit(45, 5500);
12     sa1.withdraw(60, 4000);
13   
14     sa0.settle(90);
15     sa1.settle(90);
16     sa0.show();    cout << endl;
17     sa1.show();    cout << endl;
18     cout << "Total: " << SavingsAccount::getTotal() << endl;
19     return 0;
20 }

运行结果截图：

合理

改进建议：部分数据还需要进行进行判断是否合法。

在类包含的头文件中，对友元函数进行声明

posted @ 2024-10-27 23:41 你午睡了ma 阅读(8) 评论(0) 编辑收藏举报

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实验2 类和对象_基础编程1

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