实验任务一
源码
1 #pragma once
2
3 #include<string>
4
5 class T {
6 public:
7 T(int x = 0, int y = 0);
8 T(const T& t);
9 T(T&& t);//移动构造函数
10 ~T();
11 void adjust(int ratio);//按系数成倍调整数据
12 void display()const;//以（m1,m2)形式显示对象信息
13
14 private:
15 int m1, m2;
16
17 public:
18 static int get_cnt();//显示对象总数
19
20 public:
21 static const std::string doc;//描述信息
22 static const int max_cnt;//对象上限
23
24 private:
25 static int cnt;//对象数目
26 friend void func();
27 };
28
29 void func();
t.h
1 #include "t.h"
2 #include <iostream>
3 #include <string>
4
5 using std::cout;
6 using std::endl;
7 using std::string;
8
9 // static成员数据类外初始化
10 const std::string T::doc{ "a simple class sample" };
11 const int T::max_cnt = 999;
12 int T::cnt = 0;
13
14
15 // 对象方法
16 T::T(int x, int y) : m1{ x }, m2{ y } {
17 ++cnt;
18 cout << "T constructor called.\n";
19 }
20
21 T::T(const T& t) : m1{ t.m1 }, m2{ t.m2 } {
22 ++cnt;
23 cout << "T copy constructor called.\n";
24 }
25
26 T::T(T&& t) : m1{ t.m1 }, m2{ t.m2 } {
27 ++cnt;
28 cout << "T move constructor called.\n";
29 }
30
31 T::~T() {
32 --cnt;
33 cout << "T destructor called.\n";
34 }
35
36 void T::adjust(int ratio) {
37 m1 *= ratio;
38 m2 *= ratio;
39 }
40
41 void T::display() const {
42 cout << "(" << m1 << ", " << m2 << ")";
43 }
44
45 // 类方法
46 int T::get_cnt() {
47 return cnt;
48 }
49
50 // 友元
51 void func() {
52 T t5(42);
53 t5.m2 = 2049;
54 cout << "t5 = "; t5.display(); cout << endl;
55 }
t.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 << "t4 = "; t4.display(); cout << endl;
34
35 cout << "T objects'current count: " << T::get_cnt() << endl;
36
37 func();
38 }
task1.cpp
运行结果
问题一：
如果func()没有被调用，并且没有其他地方依赖于它的实现，那么从项目中移除func()的定义或调用通常不会影响编译和运行。然而，如果func()的声明（作为友元）被保留，但实现被移除，并且其他代码（如测试代码或未来的开发）试图调用func()，那么这将导致链接错误，因为找不到func()的实现。
问题二：
1.T(int x = 0, int y = 0);为带有默认参数的默认构造函数。
功能：当创建对象时没有提供任何初始化参数时，使用此构造函数。它允许对象以某种默认状态被创建。
调用时机：在创建对象时，如果没有提供足够的参数来匹配其他构造函数，则调用默认构造函数。
2.T(const T& t);为拷贝构造函数。
功能：用于创建一个新对象，作为另一个同类型对象的副本。它接受一个对同类型对象的常量引用作为参数。
调用时机：当使用另一个同类型对象初始化新对象时（如T obj2 = obj1;）；
当对象作为函数参数按值传递时；
当对象从函数按值返回时。
3.T(T&& t);为移动构造函数。
功能：从t中窃取资源并初始化新对象，为避免不必要的资源复制
调用时机：当使用std::move显式地将对象转换为右值，并用于初始化新对象时。
4.~T();为析构函数。
功能：析构函数在对象生命周期结束时自动调用，用于执行清理操作，如释放对象占用的资源（如动态分配的内存、文件句柄等）。
调用时机：当对象的生命周期结束时，如离开作用域（对于局部变量）、被删除（对于动态分配的对象）、或容器（如std::vector）被销毁且包含该类型的对象时。
问题三：
不行
实验任务二
源码
1 #pragma once
2
3 #include<string>
4
5 class Complex {
6 public:
7 static const std::string doc;
8 private:
9 double real; double imag;
10 public:
11 Complex(double r = 0, double i = 0);
12 Complex(const Complex& c);
13
14 double get_real()const;
15 double get_imag()const;
16
17 void add(const Complex& other);
18
19 friend Complex add(const Complex& c1, const Complex& c2);
20 friend bool is_equal(const Complex& c1, const Complex& c2);
21 friend bool is_not_equal(const Complex& c1, const Complex& c2);
22 friend double abs(const Complex& c);
23 friend void output(const Complex& c);
24 };
Complex.h
1 #include"Complex.h"
2 #include<iostream>
3 #include<string>
4
5 using std::cout;
6 using std::endl;
7 using std::cin;
8 using std::string;
9
10 const std::string Complex::doc{ "a simplified complex class" };
11
12 Complex::Complex(double r,double i):real{r},imag{i}{}
13 Complex::Complex(const Complex& comp) :real{ comp.real }, imag{ comp.imag } {};
14
15 double Complex::get_real()const { return real; }
16 double Complex::get_imag()const { return imag; }
17
18 void Complex::add(const Complex& other) {
19 real += other.real;
20 imag += other.imag;
21 }
22
23 Complex add(const Complex& c1, const Complex& c2) {
24 return Complex(c1.real + c2.real, c1.imag + c2.imag);
25 }
26
27 bool is_equal(const Complex& c1, const Complex& c2) {
28 if (c1.real == c2.real)
29 if (c1.imag == c2.imag)
30 return true;
31 return false;
32 }
33
34 bool is_not_equal(const Complex& c1, const Complex& c2) {
35 if (c1.real == c2.real)
36 if (c1.imag == c2.imag)
37 return false;
38 return true;
39 }
40
41 double abs(const Complex& c) {
42 return sqrt(c.real * c.real + c.imag * c.imag);
43 }
44
45 void output(const Complex& c) {
46 cout << c.real << "+" << c.imag;
47 }
Complex.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 }
task2.cpp
运行结果
实验任务三
源码
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complex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 }
task3.cpp
运行结果
思考：
1.提供了：构造函数（能自定义对象类型），取模，比较
2.可以提供接口自定义对象类型
实验任务四
源码
1 #pragma once
2 #include<iostream>
3 #include<string>
4 #include<algorithm>
5
6 class Fraction {
7 private:
8 int up;
9 int down;
10 public:
11 static const std::string doc;
12
13 Fraction(int u = 0, int d = 1);
14 Fraction(const Fraction& other);
15
16 int get_up() const;
17 int get_down() const;
18
19 Fraction negative() const;
20
21 friend void simplify(Fraction&f);
22
23 friend void output(const Fraction& f);
24 friend Fraction add (const Fraction& f1, const Fraction& f2);
25 friend Fraction sub(const Fraction& f1, const Fraction& f2);
26 friend Fraction mul(const Fraction& f1, const Fraction& f2);
27 friend Fraction div(const Fraction& f1, const Fraction& f2);
28
29 };
Fraction.h
1 #include"Fraction.h"
2 #include<iostream>
3
4
5 const std::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.";
6
7 Fraction::Fraction(int u, int d) :up(u), down(d) { simplify(*this); };
8 //用this指针
9 Fraction::Fraction(const Fraction& other) :up(other.up), down(other.down) {};
10
11 int Fraction::get_up() const{
12 return up;
13 }
14 int Fraction::get_down() const{
15 return down;
16 }
17
18 //求负分数
19 Fraction Fraction:: negative() const{
20 return Fraction(-up, -down);
21 }
22
23 void simplify(Fraction& f) {
24 //化简，先求最大公约数
25 int a = f.up, b = f.down;
26 int temp;
27 while (b != 0) {
28 temp = b;
29 b = a % b;
30 a = temp;
31 }
32 int gcd = a;//最大公约数
33 f.up /= gcd;
34 f.down /= gcd;
35
36 //确保分母为正
37 if (f.down < 0) {
38 f.up = -f.up;
39 f.down = -f.down;
40 }
41 }
42
43 //输出分数
44 void output(const Fraction& f) {
45 if (f.down == 0)return;
46 if (f.down == 1) {
47 std::cout << f.up << std::endl;
48 return;
49 }
50 std::cout << (f.up<0?"-" :"") <<std::abs(f.up)<< "/" << f.down << std::endl;
51 }
52
53 //分数加法
54 Fraction add(const Fraction& f1, const Fraction& f2) {
55 Fraction result;
56 result.up = f1.up * f2.down + f2.up * f1.down;
57 result.down = f1.down * f2.down;
58 simplify(result);
59 return result;
60 }
61
62 //分数减法
63 Fraction sub(const Fraction& f1, const Fraction& f2) {
64 Fraction result(f1.up * f2.down - f2.up * f1.down, f1.down * f2.down);
65 simplify(result);
66 return result;
67 }
68
69 //分数乘法
70 Fraction mul(const Fraction& f1, const Fraction& f2) {
71 Fraction result(f1.up * f2.up, f1.down * f2.down);
72 simplify(result);
73 return result;
74 }
75
76 //分数除法
77 Fraction div(const Fraction& f1, const Fraction& f2) {
78 if (f2.up == 0) {
79 std::cout<<"分母不能为0"<<std::endl;
80 return Fraction(0,0);
81 }
82 Fraction result;
83 result.up = f1.up * f2.down; // 分子相乘（f1的分子乘以f2的分母）
84 result.down = f1.down * f2.up; // 分母相乘（f1的分母乘以f2的“分子”，但f2的分子在这里视为其倒数的分母部分）
85 simplify(result); // 化简
86 return result;
87 }
Fraction.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 }
task4.cpp
运行结果
实验任务五
源码
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 return accumulation + balance * (date - lastDate);
13 }
14 public:
15 SavingsAccount(int date, int id, double rate);
16 int getId() const { return id; }
17 double getBalance() const { return balance; }
18 double getRate() const { return rate; }
19 static double getTotal() { return total; }
20 void deposit(int date, double amount);
21 void withdraw(int date, double amount);
22 void settle(int date);
23 void show() const;
24 };
accout.h
1 #include "account.h"
2 #include <cmath>
3 #include <iostream>
4 using namespace std;
5
6 double SavingsAccount::total = 0;
7 SavingsAccount::SavingsAccount(int date, int id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
8 cout << date << "\t#" << id << " is created" << endl;
9 }
10 void SavingsAccount::record(int date, double amount) {
11 accumulation = accumulate(date);
12 lastDate = date;
13 amount = floor(amount * 100 + 0.5) / 100;
14 balance += amount;
15 total += amount;
16 cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl;
17 }
18
19 void SavingsAccount::deposit(int date, double amount) {
20 record(date, amount);
21 }
22
23
24 void SavingsAccount::withdraw(int date, double amount) {
25 if (amount > getBalance())
26 cout << "Error:not enough money" << endl;
27 else
28 record(date, -amount);
29 }
30 void SavingsAccount::settle(int date) {
31 double interest = accumulate(date) * rate / 365;
32 if (interest != 0)
33 record(date, interest);
34 accumulation = 0;
35 }
36 void SavingsAccount::show() const {
37 cout << "#" << id << "\tBalance:" << balance;
38 }
account.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
17 sa0.show(); cout << endl;
18 sa1.show(); cout << endl;
19 cout << "Total:" << SavingsAccount::getTotal() << endl;
20 return 0;
21 }
5.11.cpp
运行结果
标签：std,const,对象,编程,int,Complex,实验,Fraction,include From： https://www.cnblogs.com/yrx0415/p/18494453