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
标签：const,对象,double,编程,int,Complex,实验,Fraction,include From： https://www.cnblogs.com/ltrbky/p/18509218