实验1 类和对象(1)

#include<iostream>
#include<string>
#include<vector>

int main()
{
    using namespace std;
    
    string s1;
    string s2{"c plus plus"};
    string s3{s2};
    string s4 = s2;
    
    s1 = "oop";
    
    vector<string> v1;
    v1.push_back(s1);
    v1.push_back(s2 + "1");
    v1.push_back(s3 + "2");
    v1.push_back(s4 + "3");
    
    cout << "ouput1: " << endl;
    for(auto item: v1)
        cout << item << endl;
        
        
        
    cout << "ouput2: ";
    for(auto p = v1.begin(); p != v1.end(); ++p)
        cout << *p << endl;
        
        
    
    cout << "ouput3: " << endl;
    for(auto i = 0; i < v1.size(); ++i)
        cout << v1[i] << endl;
        
        
    vector<string> v2{v1.rbegin(), v1.rend()};
    
    
    cout << "v2: " << endl;
    for(auto item: v2)
        cout << item << endl; 
}

#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <cstdlib>
#include <time.h>


template<typename T>
void output(const T& obj)
{
    for(auto item: obj)
        std::cout << item << " ";
    std::cout << std::endl;
}

int main()
{
    using namespace std;
    
    vector<int> v1{1, 9, 8, 4};
    v1.insert(v1.begin(), 2022);
    v1.insert(v1.end(), 2023);
    
    cout << "v1: ";
    output(v1);
    
    v1.pop_back();
    v1.erase(v1.begin());
    cout << "v1: ";
    output(v1);
    
    vector<string> v2{"《1984》", "《动物农场》", "《美丽新世界》"};
    cout << "v2: ";
    output(v2);
}

#include <iostream>
using std::cout;
using std::endl;


class Point {
public: 
    Point(int x0 = 0, int y0 = 0);
    Point(const Point&p );
    ~Point() = default;
    
    int get_x() const { return x; }
    int get_y() const { return y; }
    void show() const;
    
private: 
    int x, y;
};

Point::Point(int x0, int y0): x{x0}, y{y0} {
    cout << "constructor called" << endl;
}

Point::Point(const Point& p): x{p.x}, y{p.y} {
     cout << "copy constructor called." << endl;
}

void Point::show() const {
    cout << "(" << x << ", "
                << y << ")" << endl;
}

int main()
{
    Point p1(4, 5);
    p1.show();
    
    Point p2 = p1;
    p2.show();
    
    Point p3{p2};
    p3.show();
    cout << p3.get_x() << endl;    
}

#include <iostream>
#include <iomanip>

using std::cout;
using std::endl;


class Clock {
public:
    Clock(int h = 0, int m = 0, int s = 0);
    Clock(const Clock& t);
    ~Clock() = default;
    
    void set_time(int h, int m = 0, int s = 0);
    
    void show_time() const;
    
private:
    int hour, minute, second;
    
};


Clock::Clock(int h, int m, int s): hour{h}, minute{m}, second{s} {
    cout << "constructor called" << endl;
}

Clock::Clock(const Clock& t): hour{t.hour}, minute{t.minute}, second{t.second} {
    cout << "copy constructor called" << endl;
}

void Clock::set_time(int h, int m, int s) {
    hour = h;
    minute = m;
    second = s;
}

void Clock::show_time() const {
    using std::setw;
    using std::setfill;

    cout << setfill('0') << setw(2) << hour << ":"
         << setw(2) << minute << ":"
         << setw(2) << second << endl;
}

Clock reset() {
    return Clock(0, 0, 0);
}

int main() 
{
    Clock c1(12, 0, 5);
    c1.show_time();

    c1 = reset();
    c1.show_time();

    Clock c2(c1);
    c2.set_time(6);
    c2.show_time();
}

#include <iostream>

class X {
public:
     X();
     ~X();
     X(int m);
     X(const X& obj);
     X(X&& obj) noexcept;
     void show() const;

private:
    int data;  
};

X::X(): data{42} {
    std::cout << "default constructor called.\n"; 
}

X::~X() {
    std::cout << "destructor called.\n";
}

X::X(int m) : data{m} {
    std::cout << "constructor called.\n";
}

X::X(const X& obj): data{obj.data} {
    std::cout << "copy constructor called.\n";
}

X::X(X&& obj) noexcept : data{obj.data} {
    std::cout << "move constructor called.\n";
}

void X::show() const {
    std::cout << data << std::endl;
}

int main()
{
    X x1;/*调用了默认构造函数X()*/
    x1.show();/*调用了显示数据的无返回值的show()函数*/

    X x2{2049};/*调用了有参数的构造函数X(int m)*/
    x2.show();

    X x3{x1};/*调用了复制构造函数X(const X& obj)*/
    x3.show(); 

    X x4{ std::move(x2) };/*调用了X(X&& obj) noexcept函数*/
    x4.show(); }

#include <iostream>
#include <iomanip>

class Rectangle {
public:
    Rectangle() { length = 2.0, width = 1,0; }
    Rectangle(double l, double w) { length = l; width = w; }
    Rectangle(Rectangle& rect) { length = rect.length, width = rect.width; }
    ~Rectangle() { }
    double len() const { return length; }
    double wide() const { return width; }
    double area() const { return length * width; }
    double circumference() const { return 2 * ( length + width ); }
    void resize(int times);
    void resize(int l_times, int w_times);

private:
    double length, width; 
};

void Rectangle::resize(int times) { length =  length * times,  width = width * times; }
void Rectangle::resize(int l_times, int w_times) { length = length * l_times,width = width * w_times; }


void output(const Rectangle &rect) {
    using namespace std;

    cout << "矩形信息: \n";
    cout << fixed << setprecision(2);

    cout << "长："<< setw(10) << rect.len() << endl;
    cout << "宽：" << setw(10) << rect.wide() << endl;
    cout << "面积: " << setw(8) << rect.area() << endl;
    cout << "周长: " << setw(8) << rect.circumference() << endl;
    cout << endl;
}

int main()
{
    Rectangle rect1;
    output(rect1);

    Rectangle rect2(10, 5);
    output(rect2);

    Rectangle rect3(rect1);
    rect3.resize(2);
    output(rect3);

    rect3.resize(5, 2);
    output(rect3);
}