实验任务1：
botton.hpp代码：
1 #pragma once
2
3 #include <iostream>
4 #include <string>
5
6 using std::string;
7 using std::cout;
8
9 // 按钮类
10 class Button {
11 public:
12 Button(const string &text);
13 string get_label() const;
14 void click();
15
16 private:
17 string label;
18 };
19
20 Button::Button(const string &text): label{text} {
21 }
22
23 inline string Button::get_label() const {
24 return label;
25 }
26
27 void Button::click() {
28 cout << "Button '" << label << "' clicked\n";
29 }
View Code
window.hpp代码:
1 #pragma once
2 #include "button.hpp"
3 #include <vector>
4 #include <iostream>
5
6 using std::vector;
7 using std::cout;
8 using std::endl;
9
10 // 窗口类
11 class Window{
12 public:
13 Window(const string &win_title);
14 void display() const;
15 void close();
16 void add_button(const string &label);
17
18 private:
19 string title;
20 vector<Button> buttons;
21 };
22
23 Window::Window(const string &win_title): title{win_title} {
24 buttons.push_back(Button("close"));
25 }
26
27 inline void Window::display() const {
28 string s(40, '*');
29
30 cout << s << endl;
31 cout << "window title: " << title << endl;
32 cout << "It has " << buttons.size() << " buttons: " << endl;
33 for(const auto &i: buttons)
34 cout << i.get_label() << " button" << endl;
35 cout << s << endl;
36 }
37
38 void Window::close() {
39 cout << "close window '" << title << "'" << endl;
40 buttons.at(0).click();
41 }
42
43 void Window::add_button(const string &label) {
44 buttons.push_back(Button(label));
45 }
View Code
task1.cpp代码：
1 #include "window.hpp"
2 #include <iostream>
3
4 using std::cout;
5 using std::cin;
6
7 void test() {
8 Window w1("new window");
9 w1.add_button("maximize");
10 w1.display();
11 w1.close();
12 }
13
14 int main() {
15 cout << "用组合类模拟简单GUI:\n";
16 test();
17 }
View Code
运行结果截图：
问题1：
自定义了两个类Botton 类和Window类
标准库类：使用iostream类、string类、vector类
Button类代表一个按钮，具有显示标签和点击的功能；Window类代表一个窗口，可以包含多个按钮，Window类中包含Button类的对象，用于表示窗口中的按钮。
问题2：
构造函数不需要 const，因为构造函数会修改对象的状态，初始化成员变量和添加初始按钮。不需要 inline，构造函数通常不适合内联。
click() display() close() add_button不需要 const，函数会输出信息并触发其他状态变化。不需要 inline，函数包含 I/O 操作和容器访问，不适合内联。
问题3：
调用window中的成员函数display时，通过字符串s显示四十个'*'分割界面。
实验任务2：
test2代码：
1 #include <iostream>
2 #include <vector>
3
4 using namespace std;
5
6 void output1(const vector<int> &v) {
7 for(auto &i: v)
8 cout << i << ", ";
9 cout << "\b\b \n";
10 }
11
12 void output2(const vector<vector<int>> v) {
13 for(auto &i: v) {
14 for(auto &j: i)
15 cout << j << ", ";
16 cout << "\b\b \n";
17 }
18 }
19
20 void test1() {
21 vector<int> v1(5, 42);
22 const vector<int> v2(v1);
23
24 v1.at(0) = -999;
25 cout << "v1: "; output1(v1);
26 cout << "v2: "; output1(v2);
27 cout << "v1.at(0) = " << v1.at(0) << endl;
28 cout << "v2.at(0) = " << v2.at(0) << endl;
29 }
30
31 void test2() {
32 vector<vector<int>> v1{{1, 2, 3}, {4, 5, 6, 7}};
33 const vector<vector<int>> v2(v1);
34
35 v1.at(0).push_back(-999);
36 cout << "v1: \n"; output2(v1);
37 cout << "v2: \n"; output2(v2);
38
39 vector<int> t1 = v1.at(0);
40 cout << t1.at(t1.size()-1) << endl;
41
42 const vector<int> t2 = v2.at(0);
43 cout << t2.at(t2.size()-1) << endl;
44 }
45
46 int main() {
47 cout << "测试1:\n";
48 test1();
49
50 cout << "\n测试2:\n";
51 test2();
52 }
View Code
运行截图：
问题1:
vector<int> 类型的向量 v1，并用值 42 初始化了它的5个元素。
常量向量 v2，它是 v1 的拷贝。由于 v2 是常量，其内容不可修改。
修改 v1 的第一个元素为 -999。
问题2：
vector 类型的向量 v1，并初始化为包含两个子向量的向量。
常量向量 v2，它是 v1 的拷贝。由于 v2 是常量，所以不可修改。
向 v1 的第一个子向量添加元素 -999。
问题3：
获取v1里的第一个子向量赋值给t1
输出t1的最后一个元素-999，验证-999已经被添加
获取v2里的第一个子向量赋值给t2
输出t2的最后一个元素3
问题4：
标准库模板类vector的复制函数使用深复制，不需要至少提供一个const成员函数作为接口。
实验任务3：
task3代码：
1 #include "vectorInt.hpp"
2 #include <iostream>
3
4 using std::cin;
5 using std::cout;
6
7 void output(const vectorInt &vi) {
8 for(auto i = 0; i < vi.get_size(); ++i)
9 cout << vi.at(i) << ", ";
10 cout << "\b\b \n";
11 }
12
13
14 void test1() {
15 int n;
16 cout << "Enter n: ";
17 cin >> n;
18
19 vectorInt x1(n);
20 for(auto i = 0; i < n; ++i)
21 x1.at(i) = i*i;
22 cout << "x1: "; output(x1);
23
24 vectorInt x2(n, 42);
25 vectorInt x3(x2);
26 x2.at(0) = -999;
27 cout << "x2: "; output(x2);
28 cout << "x3: "; output(x3);
29 }
30
31 void test2() {
32 const vectorInt x(5, 42);
33 vectorInt y(10, 0);
34
35 cout << "y: "; output(y);
36 y.assign(x);
37 cout << "y: "; output(y);
38
39 cout << "x.at(0) = " << x.at(0) << endl;
40 cout << "y.at(0) = " << y.at(0) << endl;
41 }
42
43 int main() {
44 cout << "测试1: \n";
45 test1();
46
47 cout << "\n测试2: \n";
48 test2();
49 }
View Code
运行截图：
问题1：
深复制
问题2：
不能正常运行，返回值类型是常数且不可以被修改
会存在安全隐患，可以通过返回值修改数据，破坏函数的封装性和数据的完整性。
问题3：
可以，但会存在额外的内存开销，因为存在复制。
实验任务4：
matrix.cpp代码：
1 #pragma once
2
3 #include <iostream>
4 #include <cassert>
5
6 using std::cout;
7 using std::endl;
8
9 // 类Matrix的声明
10 class Matrix {
11 public:
12 Matrix(int n, int m); // 构造函数，构造一个n*m的矩阵, 初始值为value
13 Matrix(int n); // 构造函数，构造一个n*n的矩阵, 初始值为value
14 Matrix(const Matrix &x); // 复制构造函数， 使用已有的矩阵X构造
15 ~Matrix();
16
17 void set(const double *pvalue); // 用pvalue指向的连续内存块数据按行为矩阵赋值
18 void clear(); // 把矩阵对象的值置0
19
20 const double& at(int i, int j) const; // 返回矩阵对象索引(i,j)的元素const引用
21 double& at(int i, int j); // 返回矩阵对象索引(i,j)的元素引用
22
23 int get_lines() const; // 返回矩阵对象行数
24 int get_cols() const; // 返回矩阵对象列数
25
26 void display() const; // 按行显示矩阵对象元素值
27
28 private:
29 int lines; // 矩阵对象内元素行数
30 int cols; // 矩阵对象内元素列数
31 double *ptr;
32 };
33
34 // 类Matrix的实现：待补足
35 Matrix::Matrix(int n,int m):lines(n),cols(m),ptr(new double[n*m]()){}
36
37 Matrix::Matrix(int n):lines(n),cols(n),ptr(new double[n*n]()){}
38
39 Matrix::Matrix(const Matrix &x):lines(x.lines),cols(x.cols),ptr(new double[lines*cols]()){
40 for(int i=0;i<lines*cols;i++)
41 ptr[i]=x.ptr[i];
42 }
43
44 Matrix::~Matrix(){
45 delete[] ptr;
46 }
47
48 void Matrix::set(const double *pvalue){
49 for(int i=0;i<lines*cols;i++)
50 ptr[i]=pvalue[i];
51 }
52
53 void Matrix::clear(){
54 for(int i=0;i<lines*cols;i++)
55 ptr[i]=0.0;
56 }
57
58 const double& Matrix::at(int i,int j) const
59 {
60 assert(i>=0&&i<lines&&j>=0&&j<cols);
61 return ptr[i*cols+j];
62 }
63
64 double &Matrix::at(int i,int j)
65 {
66 assert(i>=0&&i<lines&&j>=0&&j<cols);
67 return ptr[i*cols+j];
68 }
69
70 int Matrix::get_lines() const{
71 return lines;
72 }
73
74 int Matrix::get_cols() const{
75 return cols;
76 }
77
78 void Matrix::display() const{
79 for(int i=0;i<lines;i++){
80 for(int j=0;j<cols;j++){
81 cout<<at(i,j)<<" ";
82 }
83 cout<<endl;
84 }
85 }
86 Matrix.hpp
View Code
tesk4代码：
1 #include "matrix.hpp"
2 #include <iostream>
3 #include <cassert>
4
5 using std::cin;
6 using std::cout;
7 using std::endl;
8
9
10 const int N = 1000;
11
12 // 输出矩阵对象索引为index所在行的所有元素
13 void output(const Matrix &m, int index) {
14 assert(index >= 0 && index < m.get_lines());
15
16 for(auto j = 0; j < m.get_cols(); ++j)
17 cout << m.at(index, j) << ", ";
18 cout << "\b\b \n";
19 }
20
21
22 void test1() {
23 double x[1000] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
24
25 int n, m;
26 cout << "Enter n and m: ";
27 cin >> n >> m;
28
29 Matrix m1(n, m); // 创建矩阵对象m1, 大小n×m
30 m1.set(x); // 用一维数组x的值按行为矩阵m1赋值
31
32 Matrix m2(m, n); // 创建矩阵对象m1, 大小m×n
33 m2.set(x); // 用一维数组x的值按行为矩阵m1赋值
34
35 Matrix m3(2); // 创建一个2×2矩阵对象
36 m3.set(x); // 用一维数组x的值按行为矩阵m4赋值
37
38 cout << "矩阵对象m1: \n"; m1.display(); cout << endl;
39 cout << "矩阵对象m2: \n"; m2.display(); cout << endl;
40 cout << "矩阵对象m3: \n"; m3.display(); cout << endl;
41 }
42
43 void test2() {
44 Matrix m1(2, 3);
45 m1.clear();
46
47 const Matrix m2(m1);
48 m1.at(0, 0) = -999;
49
50 cout << "m1.at(0, 0) = " << m1.at(0, 0) << endl;
51 cout << "m2.at(0, 0) = " << m2.at(0, 0) << endl;
52 cout << "矩阵对象m1第0行: "; output(m1, 0);
53 cout << "矩阵对象m2第0行: "; output(m2, 0);
54 }
55
56 int main() {
57 cout << "测试1: \n";
58 test1();
59
60 cout << "测试2: \n";
61 test2();
62 }
View Code
运行截图：
实验任务5：
user.cpp代码：
1 #include<bits/stdc++.h>
2 using namespace std;
3 class User{
4 private:
5 string name;
6 string password;
7 string email;
8
9 public:
10 User(const string &name,const string &password="123456", const string &email=""):name(name),password(password),email(email){}
11 void set_email(){
12 string _email;
13 int tag=0;
14 cout<<"Enter email address: ";
15 while(tag==0){
16 cin>>_email;
17 int len=sizeof(_email);
18 for(int i=0;i<len;i++){
19 if(_email[i]=='@')
20 tag=1;
21 }
22 if(tag)
23 cout<< "email is set successfully..."<<endl;
24 else
25 cout<<"illegal email. Please re-enter email:";
26 }
27
28 }
29
30 void change_password(){
31 int attempt=3;
32 string old_password , new_password;
33 cout<<"Enter old password: ";
34 while(attempt>0){
35 attempt--;
36 cin>>old_password;
37 if(old_password==password){
38 cout<<"Enter new password: ";
39 cin>>new_password;
40 password=new_password;
41 cout<<"new password is set successfully..."<<endl;
42 return ;
43 }
44 else{
45 cout<<"password input error. Please re-enter again: ";
46 }
47 }
48 cout<<"password input error. Please try after a while. "<<endl;
49 }
50
51 void display() const {
52 cout<<"name: "<<name<<endl;
53 cout<<"pass: ";
54 int length=sizeof(password);
55 for(int i=1;i<=length;i++)
56 cout<<"*";
57 cout<<endl;
58 cout<<"email: "<<email<<endl;
59 }
60 };
View Code
tesk5:
1 #include "user.hpp"
2 #include <iostream>
3 #include <vector>
4 #include <string>
5
6 using std::cin;
7 using std::cout;
8 using std::endl;
9 using std::vector;
10 using std::string;
11
12 void test() {
13 vector<User> user_lst;
14
15 User u1("Alice", "2024113", "[email protected]");
16 user_lst.push_back(u1);
17 cout << endl;
18
19 User u2("Bob");
20 u2.set_email();
21 u2.change_password();
22 user_lst.push_back(u2);
23 cout << endl;
24
25 User u3("Hellen");
26 u3.set_email();
27 u3.change_password();
28 user_lst.push_back(u3);
29 cout << endl;
30
31 cout << "There are " << user_lst.size() << " users. they are: " << endl;
32 for(auto &i: user_lst) {
33 i.display();
34 cout << endl;
35 }
36 }
37
38 int main() {
39 test();
40 }
View Code
运行结果截图：
实验任务6：
data.h代码：
1 #pragma once
2 class Date{
3 private:
4 int year;
5 int month;
6 int day;
7 int totalDays;
8 public:
9 Date(int year, int month, int day) ;
10 int getYear() const {return year;}
11 int getMonth() const {return month;}
12 int getDay() const {return day;}
13 int getMaxDay() const;
14 bool isLeapYear() const {
15 return year%4==0 &&year%100 !=0 || year%400==0;
16 }
17 void show() const;
18 int distance(const Date& date) const {
19 return totalDays-date.totalDays;
20 }
21 };
22 date.h
View Code
data.cpp代码：
#include "date.h"
#include <iostream>
#include <cstdlib>
using namespace std;
namespace {
const int DAYS_BEFORE_MONTH[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
}
Date::Date(int year, int month, int day) : year(year), month(month), day(day) {
if (day <= 0 || day > getMaxDay()) {
cout << "Invalid date:";
show();
cout << endl;
exit(1);
}
int years = year - 1;
totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFORE_MONTH[month - 1] + day;
if (isLeapYear() && month > 2)
totalDays++;
}
int Date::getMaxDay()const {
if (isLeapYear() && month == 2)
return 29;
else
return DAYS_BEFORE_MONTH[month] - DAYS_BEFORE_MONTH[month - 1];
}
void Date::show() const {
cout << getYear() << " - " << getMonth() << " - " << getDay();
}
View Code
accout.h代码：
1 #ifndef __ACCOUNT_H__
2 #define __ACCOUNT_H__
3 #include "date.h"
4 #include <string>
5 class SavingsAccount {
6
7 private:
8 std::string id;
9 double balance,rate,accumulation;
10 Date lastDate;
11 static double total;
12
13 void record(const Date& date, double amount, const std::string& desc);
14
15 void error(const std::string& msg) const;
16
17 double accumulate(const Date& date) const {
18 return accumulation + balance * date.distance(lastDate);
19 }
20 public:
21 SavingsAccount(const Date& date, const std::string& id, double rate);
22 const std::string& getId() const {
23 return id;
24 }
25 double getBalance() const {
26 return balance;
27 }
28 double getRate() const {
29 return rate;
30 }
31 static double getTotal() {
32 return total;
33 }
34
35 void deposit(const Date& date, double amount, const std::string& desc);
36
37 void withdraw(const Date& date, double amount, const std::string& desc);
38
39 void settle(const Date& date);
40
41 void show() const;
42 };
43 #endif
View Code
accout.cpp代码：
1 #include "account.h"
2 #include <cmath>
3 #include <iostream>
4 using namespace std;
5 double SavingsAccount::total = 0;
6 SavingsAccount::SavingsAccount(const Date& date, const string& id, double rate) :id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
7 date.show();
8 cout << "\t#" << id << "created" << endl;
9 }
10 void SavingsAccount::record(const Date& date, double amount, const string& desc) {
11 accumulation = accumulate(date);
12 lastDate = date;
13 amount = floor(amount * 100 + 0.5) / 100;
14 balance += amount;
15 total += amount;
16 date.show();
17 cout << "t\#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
18 }
19 void SavingsAccount::error(const string& msg) const {
20 cout << "Error(# " << id << " ): " << msg << endl;
21 }
22 void SavingsAccount::deposit(const Date & date, double amount, const string & desc) {
23 record(date, amount, desc);
24 }
25 void SavingsAccount::withdraw(const Date & date, double amount, const string& desc) {
26 if (amount > getBalance())
27 error("not enough money");
28 else
29 record(date, -amount, desc);
30 }
31 void SavingsAccount::settle(const Date& date) {
32 double interest = accumulate(date) * rate//计算年息
33 / date.distance(Date(date.getYear() - 1, 1, 1));
34 if (interest != 0)
35 record(date, interest, "interest");
36 accumulation = 0;
37 }
38 void SavingsAccount::show() const {
39 cout << "ID: "<< id << "\tBalance:" << balance;
40 }
View Code
6_25.cpp代码：
1 #include "account.h"
2 #include <iostream>
3 using namespace std;
4 int main() {
5
6 Date date(2008, 11, 1);
7 SavingsAccount accounts[] = {
8 SavingsAccount(date,"03755217",0.015),
9 SavingsAccount(date, "02342342", 0.015)
10 };
11 const int n = sizeof(accounts) / sizeof(SavingsAccount);
12
13 accounts[0].deposit(Date(2008, 11, 5), 5000, "salary");
14 accounts[1].deposit(Date(2008, 11, 25), 10000, "sell stock 0323");
15
16 accounts[0].deposit(Date(2008, 12, 5), 5500, "salary");
17 accounts[1].withdraw(Date(2008, 12, 20), 4000, "buy a laptop");
18
19 cout << endl;
20 for (int i = 0; i < n; i++) {
21 accounts[i].settle(Date(2009, 1, 1));
22 accounts[i].show();
23 cout << endl;
24 }
25 cout << "Total: " << SavingsAccount::getTotal() << endl;
26 return 0;
27 }
View Code
运行截图：
标签：std,const,cout,对象,int,实验,include,string From： https://www.cnblogs.com/yr123/p/18525842