实验任务1：
t.h代码：
1 #pragma once
2 #include <string>
3 // 类T: 声明
4 class T {
5 // 对象属性、方法
6 public:
7 T(int x = 0, int y = 0); // 普通构造函数
8 T(const T &t); // 复制构造函数
9 T(T &&t); // 移动构造函数
10 ~T(); // 析构函数
11 void adjust(int ratio); // 按系数成倍调整数据
12 void display() const; // 以(m1, m2)形式显示T类对象信息
13 private:
14 int m1, m2;
15 // 类属性、方法
16 public:
17 static int get_cnt(); // 显示当前T类对象总数
18 public:
19 static const std::string doc; // 类T的描述信息
20 static const int max_cnt; // 类T对象上限
21 private:
22 static int cnt; // 当前T类对象数目
23 // 类T友元函数声明
24 friend void func();
25 };
26 // 普通函数声明
27 void func();
28
29
30 // static成员数据类外初始化
31 const std::string T::doc{"a simple class sample"};
32 const int T::max_cnt = 999;
33 int T::cnt = 0;
View Code
t.cpp代码：
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 }
View Code
task1.cpp代码：
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 }
View Code
运行结果截图：
问题1：
可以运行，因为在t.cpp中有func函数的定义，主程序运行时可以查找到func函数的定义，那么即使不在类T的定义中再次声明其为友元，编译器也能正确识别和处理func函数对类私有成员的访问。正常情况下，如果func函数在类外部没有任何声明或定义，且尝试在源文件中调用它，那么编译器将会报错，因为它不知道func函数的存在。
问题2：
普通构造函数 (T(int x = 0, int y = 0)):用于创建类T的对象，并初始化成员变量m1和m2为指定的值。在创建对象时自动调用。
复制构造函数 (T(const T& t)):用于创建一个新的对象，并将其初始化为另一个同类型对象的副本。当一个对象以值传递的方式传递给函数、或从函数返回对象、或进行对象赋值操作时。
移动构造函数 (T(T&& t)):用于获得另一个右值对象的资源，而不是复制它们。当右值对象被用作初始值来构造新对象时。
析构函数 (~T()):在对象生命周期结束时自动调用，用于执行清理操作，如释放对象所占用的资源。对象离开其作用域时。
问题3：
我使用的时DevC++中可以运行，调整的代码与t.cpp中其他代码未产生关联，故无影响。
实验任务2：
Complex.h代码:
1 #pragma once
2 #include<string>
3
4 class Complex{
5 public:
6 Complex(double x=0,double y=0);
7 Complex(const Complex &c);
8
9 ~Complex();
10 void display() cosnt;
11
12 double const get_real(){
13 return r;
14 };
15 double const get_imag(){
16 return i;
17 };
18
19 private:
20 double r,i;
21
22 friend Complex add(const Complex& c1,const Complex& c2);
23 friend bool is_equal(const Complex& c1,const Complex& c2);
24 friend bool is_not_equal(const Complex& c1,const Complex& c3);
25 friend double abs(const Complex& c);
26 friend void output(const Complex& c);
27
28 public:
29 static const std::string doc;
30 };
31
32 Complex add();
33 bool is_equal();
34 bool is_not_equal();
35 void output();
36 void abs();
View Code
Complex.cpp代码:
1 #include"Complex.h"
2 #include<bits/stdc++.h>
3
4 using namespace std;
5
6 const string Complex::doc{"a simplified complex class"};
7
8 Complex::Complex(double r,double i):real{r},imag{i}{
9 }
10
11 Complex::Complex(const Complex& c):real{c.real},imag{c.imag}{
12
13 }
14
15
16 Complex Complex::add(const Complex &c){
17 real+=c.real;
18 imag+=c.imag;
19 }
20
21 Complex add(const Complex& c1,const Complex& c2)
22 {
23 Complex c4;
24 c4.imag=c1.imag+c2.imag;
25 c4.real=c1.real+c2.real;
26 return c4;
27 }
28 bool is_equal(const Complex& c1,const Complex& c2){
29 if(c1.imag==c2.imag&&c1.real==c2.real)
30 return true;
31 else
32 return false;
33 }
34 bool is_not_equal(const Complex &c1,const Complex &c3){
35 if(c1.imag==c3.imag&&c1.real==c3.real)
36 return false;
37 else
38 return true;
39 }
40 double abs(const Complex &c)
41 {
42 double s;
43 s=sqrt(c.imag*c.imag+c.real*c.real);
44 return s;
45 }
46 void output(const Complex &c){
47 cout<<c.real;
48 if(c.imag>=0) cout<<" + "<<c.imag<<"i"<<endl;
49 else cout<<" - "<<(-1)*c.imag<<"i"<<endl;
50 }
51 Complex::~Complex(){
52
53 }
View Code
task2.cpp代码:
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 }
View Code
运行结果截图：
实验任务3：
task3.cpp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 }
View Code
运行结果截图：
问题1：
接口有：
complex 模板类的默认构造函数、带实部和虚部的构造函数、带单个实部的构造函数、拷贝构造函数、实部和虚部的访问函数、模的计算 abs()
问题2：
类的定义与声明已经由C++标准库定义和实现，提供了丰富的运算接口，包括加减乘除、取模、相等比较等，且都是经过优化的实现，可以自动管理内存和资源。
成员函数的调用与运算可以直接使用运算符重载进行运算，如 c1 += c2，输出运算符 << 进行输出，如 cout << c1。
问题3：
适当的使用标准库complex模板类，使代码更简洁，因为只需要包含头文件和测试代码。可以直接使用标准库提供的接口，无需手动编写和调试运算函数和输出函数。
实验任务4：
Fraction.h代码：
1 #pragma once
2 #include<string>
3
4 using std::string;
5 class Fraction {
6
7 public:
8 Fraction(int x,int y=1);
9 Fraction(const Fraction &f);
10 ~Fraction();
11
12 public:
13 int get_up() const;
14 int get_down() const;
15 Fraction negative();
16
17 Fraction simplify();
18
19 private:
20 int up,down;
21 friend void output(const Fraction &f);
22 friend Fraction add(const Fraction &f1,const Fraction &f2);
23 friend Fraction sub(const Fraction &f1,const Fraction &f2);
24 friend Fraction mul(const Fraction &f1,const Fraction &f2);
25 friend Fraction div(const Fraction &f1,const Fraction &f2);
26
27 public:
28 static const string doc;
29 };
30
31 void output(const Fraction& f1);
32 Fraction add(const Fraction& f1, const Fraction& f2);
33 Fraction sub(const Fraction& f1, const Fraction& f2);
34 Fraction mul(const Fraction& f1, const Fraction& f2);
35 Fraction div(const Fraction& f1, const Fraction& f2);
View Code
Fraction.cpp代码:
1 #include <iostream>
2 #include <string>
3 #include "Fraction.h"
4
5 using std::cout;
6 using std::endl;
7 using std::string;
8
9 const string Fraction::doc{
10 "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."
11 };
12
13 Fraction::Fraction(int x,int y):up{x},down{y}{}
14 Fraction::Fraction(const Fraction &f):up{f.up},down{f.down}{}
15 Fraction::~Fraction(){}
16
17
18 int Fraction::get_up() const{
19 return up;
20 }
21
22 int Fraction::get_down() const{
23 return down;
24 }
25
26 Fraction Fraction::negative() {
27 Fraction t = simplify();
28 return Fraction(-t.up,t.down);
29 }
30
31 Fraction Fraction::simplify()
32 {
33 int small, x, y, z;
34 if (up >= 0)
35 {
36 x = up;
37 if (down > 0)
38 {
39 y = down;
40 z = 1;
41 }
42 else
43 {
44 y = -down;
45 z = -1;
46 }
47 }
48 else
49 {
50 x = -up;
51 if (down > 0)
52 {
53 y = down;
54 z = -1;
55 }
56 else
57 {
58 y = -down;
59 z = 1;
60 }
61 }
62 if (x > y)
63 small = y;
64 else
65 small = x;
66 int i;
67 for (i = small; i >= 1; i--)
68 if (x % i == 0 && y % i == 0)
69 {
70 x = x / i;
71 y = y / i;
72 break;
73 }
74 if (z == 1)
75 return Fraction(x, y);
76 return Fraction(-x, y);
77 }
78
79 void output(const Fraction& f){
80 Fraction t = Fraction(f.up,f.down);
81 t = t.simplify();
82 if(t.down == 0) cout << "分母不能为0";
83 else {
84 if(t.up == 0)
85 cout << "0";
86 else if(t.up != 0 && t.down == 1)
87 cout << t.up;
88 else
89 cout << t.up << "/" << t.down;
90 cout << endl;
91 }
92 }
93 Fraction add(const Fraction &f1,const Fraction &f2) {
94 int num = f1.up * f2.down + f2.up * f1.down;
95 int denom = f1.down * f2.down;
96 return Fraction(num, denom);
97 }
98 Fraction sub(const Fraction &f1,const Fraction &f2) {
99 int num = f1.up * f2.down - f2.up * f1.down;
100 int denom = f1.down * f2.down;
101 return Fraction(num, denom);
102 }
103 Fraction mul(const Fraction &f1,const Fraction &f2) {
104 return Fraction(f1.up*f2.up,f1.down*f2.down);
105
106 }
107 Fraction div(const Fraction &f1,const Fraction &f2) {
108 return Fraction(f1.up*f2.down,f1.down*f2.up);
109
110 }
View Code
task4.cpp代码:
1 #include "Fraction.h"
2 #include <iostream>
3 using std::cout;
4 using std::endl;
5 void test1() {
6 cout << "Fraction类测试: " << endl;
7 cout << Fraction::doc << endl << endl;
8 Fraction f1(5);
9 Fraction f2(3, -4), f3(-18, 12);
10 Fraction f4(f3);
11 cout << "f1 = ";
12 output(f1);
13 cout << endl;
14 cout << "f2 = ";
15 output(f2);
16 cout << endl;
17 cout << "f3 = ";
18 output(f3);
19 cout << endl;
20 cout << "f4 = ";
21 output(f4);
22 cout << endl;
23 Fraction f5(f4.negative());
24 cout << "f5 = ";
25 output(f5);
26 cout << endl;
27 cout << "f5.get_up() = " << f5.get_up() << ", f5.get_down() = " <<
28 f5.get_down() << endl;
29 cout << "f1 + f2 = ";
30 output(add(f1, f2));
31 cout << endl;
32 cout << "f1 - f2 = ";
33 output(sub(f1, f2));
34 cout << endl;
35 cout << "f1 * f2 = ";
36 output(mul(f1, f2));
37 cout << endl;
38 cout << "f1 / f2 = ";
39 output(div(f1, f2));
40 cout << endl;
41 cout << "f4 + f5 = ";
42 output(add(f4, f5));
43 cout << endl;
44 }
45 void test2() {
46 Fraction f6(42, 55), f7(0, 3);
47 cout << "f6 = ";
48 output(f6);
49 cout << endl;
50 cout << "f7 = ";
51 output(f7);
52 cout << endl;
53 cout << "f6 / f7 = ";
54 output(div(f6, f7));
55 cout << endl;
56 }
57 int main() {
58 cout << "测试1: Fraction类基础功能测试\n";
59 test1();
60 cout << "\n测试2: 分母为0测试: \n";
61 test2();
62 }
View Code
运行结果截图：
实验任务5：
account.h代码：
1 #pragma once
2 class SavingsAccount {
3 private:
4 int id;
5 double balance;
6 double rate;
7 int lastDate;
8 double accumulation;
9 static double total;
10 void record(int date, double amount);
11 double accumulate(int date) const
12 {
13 return accumulation + balance * (date - lastDate);
14 }
15 public:
16 SavingsAccount(int date, int id, double rate);
17 int getId()const { return id; }
18 double getBalance()const { return balance; }
19 double getRate()const { return rate; }
20 static double getTotal() { return total; }
21 void deposit(int date, double amount);
22 void withdraw(int date, double amount);
23 void settle(int date);
24 void show()const;
25 };
View Code
account.cpp代码：
1 #include"account.h"
2 #include<cmath>
3 #include<iostream>
4 using namespace std;
5 double SavingsAccount::total = 0;
6
7
8 SavingsAccount::SavingsAccount(int date, int id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0)
9 {
10 cout << date << "\t#" << id << " is created" << endl;
11 }
12
13 void SavingsAccount::record(int date, double amount)
14 {
15 accumulation = accumulate(date);
16 lastDate = date;
17 amount = floor(amount * 100 + 0.5) / 100;
18 balance += amount;
19 total += amount;
20 cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl;
21 }
22 void SavingsAccount::deposit(int date, double amount) {
23 record(date, amount);
24 }
25 void SavingsAccount::withdraw(int date, double amount) {
26 if (amount > getBalance())
27 cout << "Error:not enough money" << endl;
28 else
29 {
30 record(date, -amount);
31 }
32 }
33 void SavingsAccount::settle(int date) {
34 double interest = accumulate(date) * rate / 365;
35 if (interest != 0)
36 record(date, interest);
37 accumulation = 0;
38 }
39 void SavingsAccount::show()const {
40 cout << "#" << id << "\tBalance:" << balance;
41 }
View Code
5.11.cpp代码：
1 #include"account.h"
2 #include<iostream>
3 using namespace std;
4 int main() {
5 SavingsAccount sa0(1, 21325302, 0.015);
6 SavingsAccount sa1(1, 58320212, 0.015);
7 sa0.deposit(5, 5000);
8 sa1.deposit(25, 10000);
9 sa0.deposit(45, 5500);
10 sa1.withdraw(60, 4000);
11 sa0.settle(90);
12 sa1.settle(90);
13 sa0.show(); cout << endl;
14 sa1.show(); cout << endl;
15 cout << "Total: " << SavingsAccount::getTotal() << endl;
16 return 0;
17 }
View Code
运行结果截图：
理解和体会：
类通过私有成员变量和公有成员函数实现了封装。外界只能通过公有成员函数来访问和操作账户信息，保证了数据的安全性和完整性。程序中使用了静态成员变量来记录总账户数，这是数据共享。同时，通过类的封装和访问权限控制，保护了账户信息不被非法访问和修改。对银行账户进行了抽象，使得代码更加简洁、易于理解和维护。
优化：
可以使用接口或抽象类来定义更多基本的功能，并通过多态性来实现不同的银行账户类型。同时，加强代码的安全性，使用一些加密函数等等。
标签：std,const,对象,int,Complex,实验,Fraction,include From： https://www.cnblogs.com/yr123/p/18514707