实验一代码：
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 }
39
40 // 类T: 实现
41 // 普通函数实现
42
43 #include "t.h"
44 #include <iostream>
45 #include <string>
46
47 using std::cout;
48 using std::endl;
49 using std::string;
50
51 // static成员数据类外初始化
52 const std::string T::doc{"a simple class sample"};
53 const int T::max_cnt = 999;
54 int T::cnt = 0;
55
56
57 // 对象方法
58 T::T(int x, int y): m1{x}, m2{y} {
59 ++cnt;
60 cout << "T constructor called.\n";
61 }
62
63 T::T(const T &t): m1{t.m1}, m2{t.m2} {
64 ++cnt;
65 cout << "T copy constructor called.\n";
66 }
67
68 T::T(T &&t): m1{t.m1}, m2{t.m2} {
69 ++cnt;
70 cout << "T move constructor called.\n";
71 }
72
73 T::~T() {
74 --cnt;
75 cout << "T destructor called.\n";
76 }
77
78 void T::adjust(int ratio) {
79 m1 *= ratio;
80 m2 *= ratio;
81 }
82
83 void T::display() const {
84 cout << "(" << m1 << ", " << m2 << ")" ;
85 }
86
87 // 类方法
88 int T::get_cnt() {
89 return cnt;
90 }
91
92 // 友元
93 void func() {
94 T t5(42);
95 t5.m2 = 2049;
96 cout << "t5 = "; t5.display(); cout << endl;
97 }
98
99 #pragma once
100
101 #include <string>
102
103 // 类T: 声明
104 class T {
105 // 对象属性、方法
106 public:
107 T(int x = 0, int y = 0); // 普通构造函数
108 T(const T &t); // 复制构造函数
109 T(T &&t); // 移动构造函数
110 ~T(); // 析构函数
111
112 void adjust(int ratio); // 按系数成倍调整数据
113 void display() const; // 以(m1, m2)形式显示T类对象信息
114
115 private:
116 int m1, m2;
117
118 // 类属性、方法
119 public:
120 static int get_cnt(); // 显示当前T类对象总数
121
122 public:
123 static const std::string doc; // 类T的描述信息
124 static const int max_cnt; // 类T对象上限
125
126 private:
127 static int cnt; // 当前T类对象数目
128
129 // 类T友元函数声明
130 friend void func();
131 };
132
133 // 普通函数声明
134 void func();
View Code
运行截图：
问题1：
不能，func（）函数未声明，所以不存在该友元函数
问题2：构造函数的作用就是在对象被创建时利用特定的值构造对象，将对象初始化为一个特定的状态。1.复制构造函数：其形参是本类的对象的引用。
其作用是使用一个已经存在的对象（由复制构造函数的参数指定），去初始化同类的一个新对象。。2.移动构造函数：左值是位于赋值语句左侧的对象
变量，右值是赋值语句右侧的值，不依附于对象。3.所有构造函数调用完后，析构函数依次调用。
问题3：
不能
实验二代码：
1 #pragma once
2
3 #include<string>
4
5
6 class Complex{
7 public:
8 Complex (double a=0, double b=0);
9 Complex (const Complex &c); friend void output(const Complex &c);
10 const double get_real();
11 const double get_imag();
12 friend double abs(const Complex &c);
13 friend bool is_equal(const Complex &c1, const Complex &c2);
14 friend bool is_not_equal(const Complex &c1, const Complex &c2);
15 friend Complex add(const Complex &c1, const Complex &c2);
16 Complex add(const Complex &c);
17 static std::string doc;
18 ~Complex();
19 private:
20 double real,imag;
21
22 };
23 void output(const Complex &c);
24 double abs(const Complex &c);
25 bool is_equal(const Complex &c1, const Complex &c2);
26 bool is_not_equal(const Complex &c1, const Complex &c2);
27 Complex add(const Complex &c1, const Complex &c2);
28
29
30
31
32 #include "Complex.h"
33 #include<iostream>
34 #include<string>
35 #include<cmath>
36
37 using namespace std;
38
39 Complex::Complex(double a,double b): real{a},imag{b}{}
40 Complex::Complex(const Complex &c){
41 real=c.real;
42 imag=c.imag;
43 }
44 Complex add(const Complex &c1,const Complex &c2){
45 Complex c;
46 c.real=c1.real+c2.real;
47 c.imag=c1.imag+c2.imag;
48 return c;
49 }
50 Complex Complex::add(const Complex &c){
51 real+=c.real;
52 imag+=c.imag;
53 }
54 const double Complex::get_real(){
55 return real;
56 }
57 const double Complex::get_imag(){
58 return imag;
59 }
60 double abs(const Complex &c){
61 double a=0;
62 a=c.real*c.real+c.imag*c.imag;
63 a=sqrt(a);
64 }
65 bool is_equal(const Complex &c1,const Complex &c2){
66 if(c1.real==c2.real && c1.imag==c2.imag)
67 return 1;
68 else
69 return 0;
70 }
71 bool is_not_equal(const Complex &c1,const Complex &c2){
72 if(c1.real!=c2.real || c1.imag!=c2.imag)
73 return 1;
74 else
75 return 0;
76 }
77 Complex::~Complex()=default;
78 string Complex::doc="a simplified Complex class";
79 void output(const Complex &c){
80 if(c.imag<0)
81 cout<<c.real<<c.imag<<"i";
82 else
83 cout<<c.real<<"+"<<c.imag<<"i";
84 }
View Code
运行截图：
实验三代码：
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
运行截图：
实验四代码：
1 #include "Fraction.h"
2
3 #include<iostream>
4
5 using namespace std;
6
7 Fraction::Fraction(int a,int b):up{a},down{b}{}
8 Fraction::Fraction(const Fraction &f){
9 up=f.up;
10 down=f.down;
11 }
12 Fraction Fraction::negative(){
13 Fraction f;
14 f.up=up*-1;
15 f.down=down;
16 return f;
17 }
18 Fraction::~Fraction()=default;
19 int Fraction::get_down(){
20 int a,b,c,d,e;
21 a=up;
22 b=down;
23 d=up;
24 e=down;
25 while(b!=0)
26 {
27 c=b;
28 b=a%b;
29 a=c;
30 }
31 d=d/a;
32 e=e/a;
33 return e;
34 }
35 int Fraction::get_up(){
36 int a,b,c,d,e;
37 a=up;
38 b=down;
39 d=up;
40 e=down;
41 while(b!=0)
42 {
43 c=b;
44 b=a%b;
45 a=c;
46 }
47 d=d/a;
48 e=e/a;
49 return d;
50 }
51 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.";
52 Fraction add(const Fraction &f1,const Fraction &f2){
53 Fraction f;
54 f.down=f1.down*f2.down;
55 f.up=f1.up*f2.down+f2.up*f1.down;
56 return f;
57 }
58 Fraction sub(const Fraction &f1,const Fraction &f2){
59 Fraction f;
60 f.down=f1.down*f2.down;
61 f.up=f1.up*f2.down-f2.up*f1.down;
62 return f;
63 }
64 Fraction mul(const Fraction &f1,const Fraction &f2){
65 Fraction f;
66 f.down=f1.down*f2.down;
67 f.up=f1.up*f2.up;
68 return f;
69 }
70 Fraction div(const Fraction &f1,const Fraction &f2){
71 Fraction f;
72 f.down=f1.down*f2.up;
73 f.up=f1.up*f2.down;
74 return f;
75 }
76 void output(const Fraction &f){
77 int a,b,c,d,e;
78 if(f.down==0)
79 cout<<"分母不能为0";
80 else
81 {
82 a=f.up;
83 b=f.down;
84 d=f.up;
85 e=f.down;
86 while(b!=0)
87 {
88 c=b;
89 b=a%b;
90 a=c;
91 }
92 d=d/a;
93 e=e/a;
94 if(e==1)
95 cout<<d;
96 else if(e<0)
97 cout<<d*-1<<"/"<<e*-1;
98 else
99 cout<<d<<"/"<<e;
100 }
101 }
102
103
104
105
106 #pragma once
107
108 #include<string>
109 class Fraction{
110 public:
111 Fraction(int a=1,int b=1);
112 Fraction(const Fraction &f);
113 int get_up();
114 int get_down();
115 Fraction negative();
116 static std::string doc;
117 friend void output(const Fraction &f);
118 friend Fraction add(const Fraction &f1,const Fraction &f2);
119 friend Fraction sub(const Fraction &f1,const Fraction &f2);
120 friend Fraction mul(const Fraction &f1,const Fraction &f2);
121 friend Fraction div(const Fraction &f1,const Fraction &f2);
122 ~Fraction();
123 private:
124 int up,down;
125 };
126 void output(const Fraction &f);
127 Fraction add(const Fraction &f1,const Fraction &f2);
128 Fraction sub(const Fraction &f1,const Fraction &f2);
129 Fraction mul(const Fraction &f1,const Fraction &f2);
130 Fraction div(const Fraction &f1,const Fraction &f2);
View Code
运行截图：
实验五代码：
1 #include"account.h"
2 #include<cmath>
3 #include<iostream>
4 using namespace std;
5 double SavingsAccount::total = 0;
6 SavingsAccount::SavingsAccount(int date, int id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
7 cout << date << "\t#" << id << "is created" << endl;
8 }
9 void SavingsAccount::record(int date, double amount) {
10 accumulation = accumulate(date);
11 lastDate = date;
12 amount = floor(amount * 100 + 0.5) / 100;
13 balance += amount;
14 total += amount;
15 cout << date << "\t#" << id << "\t" << amount << "\t" << balance << endl;
16 }
17 void SavingsAccount::deposit(int date, double amount) {
18 record(date, amount);
19 }
20 void SavingsAccount::withdraw(int date,double amount) {
21 if (amount > getBalance())
22 cout << "Error:not enough money" << endl;
23 else {
24 record(date, -amount);
25 }
26 }
27 void SavingsAccount::settle(int date) {
28 double interest = accumulate(date) * rate / 365;
29 if (interest != 0)
30 record(date, interest);
31 accumulation = 0;
32 }
33 void SavingsAccount::show()const {
34 cout << "#" << id << "\tBalance:" << balance;
35 }
36
37
38
39 #include"account.h"
40 #include<iostream>
41 using namespace std;
42 int main() {
43 SavingsAccount sa0(1, 21325302, 0.015);
44 SavingsAccount sa1(1, 58320212, 0.015);
45 sa0.deposit(5, 5000);
46 sa1.deposit(25, 10000);
47 sa0.deposit(45, 5500);
48 sa1.withdraw(60, 4000);
49 sa0.settle(90);
50 sa1.settle(90);
51 sa0.show(); cout << endl;
52 sa1.show(); cout << endl;
53 cout << "Total: " << SavingsAccount::getTotal() << endl;
54 return 0;
55 }
56
57
58
59
60 #pragma once
61 class SavingsAccount {
62 private:
63 int id;
64 double balance;
65 double rate;
66 int lastDate;
67 double accumulation;
68 static double total;
69 void record(int date, double amount);
70 double accumulate(int date) const {
71 return accumulation + balance * (date - lastDate);
72 }
73 public:
74 SavingsAccount(int date, int id, double rate);
75 int getId()const { return id; }
76 double getBalance()const { return balance; }
77 double getRate()const { return rate; }
78 static double getTotal() { return total; }
79 void deposit(int date, double amount);
80 void withdraw(int date, double amount);
81 void settle(int date);
82
83 void show()const;
84 };
View Code
运行截图：
标签：const,int,up,down,Complex,实验,Fraction From： https://www.cnblogs.com/ywq121/p/18494463