实验一 类和对象

#include<iostream>
#include<iomanip>
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(3,4);
    p1.show();
    
    Point p2=p1;
    p2.show();
    
    Point p3{p2};
    p3.show();
    cout<<p3.get_x()<<endl;
}

实验3

#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(2, 0, 51); 
        c1.show_time();

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

        Clock c2(c1); 
        c2.set_time(3); 
        c2.show_time();
    }

实验四

#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; 
    x1.show(); 
    
    X x2{2049}; 
    x2.show();

    X x3{x1}; 
    x3.show(); 

    X x4{ std::move(x2) }; 
    x4.show();
}

32行：调用默认构造函数

35行：调用构造函数

38行：调用复制构造函数

41行：调用移动构造函数

析构函数在对象被销毁时被调用

实验五

#include <iostream>
#include <iomanip>
using namespace std;
class Rectangle
{
public:
    Rectangle(double l = 2.0, double w = 1.0) : length(l), width(w) {}

    Rectangle(const Rectangle& rect) : length(rect.length), width(rect.width){}

    ~Rectangle() {};

    double len() 
    {
        return length;
    }
    double wide() 
    {
        return width;
    }
    double area() 
    {
        return length * width;
    }
    double circumference() const
    {
        return (length + width) * 2;
    }
    void resize(int times)
    {
        length *= times;
        width *= times;
    }
    void resize(int l_times, int w_times)
    {
        length *= l_times;
        width *= w_times;
    }
 
private:
    double length, width;
};

void output(const Rectangle& rect)
{
    using namespace std;
    cout << "矩阵信息:\n";
    cout << fixed << setprecision(2);
    cout << "长:" << rect.len() << endl;
    cout << "宽:" << rect.wide() << endl;
    cout << "面积:" << rect.area() << endl;
    cout << "周长:" << rect.circumference() << 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);

}