实验一

实验2

 1 #include <iostream>
 2    using std::cout;
 3    using std::endl;
 4    class Point
 5 
 6 {
 7       public:
 8           Point(int x0 = 0, int y0 = 0);
 9           Point(const Point&p );
10           ~Point() = default;
11           int get_x() const { return x; }
12           int get_y() const { return y; }
13           void show() const;
14           private:
15           int x, y;
16 };
17 
18 Point::Point(int x0, int y0): x{x0}, y{y0}
19 
20 {
21            cout << "constructor called." << endl;
22 }
23 
24 Point::Point(const Point& p): x{p.x}, y{p.y}
25 
26 {
27            cout << "copy constructor called." << endl;
28 }
29 
30 void Point::show() const
31 
32 {
33           cout << "(" << x << ", "
34           << y << ")" << endl;
35 }
36    int main()
37 
38 {
39              Point p1(4, 5);
40              p1.show();
41              Point p2 = p1;
42              p2.show();
43              Point p3{p2};
44              p3.show();
45              cout << p3.get_x() << endl;
46 }

运行结果以及更换数据元素后的结果。                                                                             

 实验3

 1 #include <iostream>
 2 #include <iomanip>
 3     using std::cout;
 4     using std::endl;
 5 
 6        class Clock
 7 
 8 {
 9        public:
10            Clock(int h = 0, int m = 0, int s = 0);
11            Clock(const Clock& t);
12            ~Clock() = default;
13            void set_time(int h, int m = 0, int s = 0);
14 
15            void show_time() const;
16       private:
17             int hour, minute, second;
18 };
19 
20 Clock::Clock(int h, int m, int s): hour{h}, minute{m}, second{s}
21 
22 {
23         cout << "constructor called" << endl;
24 }
25 Clock::Clock(const Clock& t): hour{t.hour}, minute{t.minute},
26 second{t.second}
27 
28 {
29          cout << "copy constructor called" << endl;
30 }
31 void Clock::set_time(int h, int m, int s)
32 
33 {
34         hour = h;
35         minute = m;
36         second = s;
37 }
38 void Clock::show_time() const
39 
40 {
41        using std::setw;
42        using std::setfill;
43        cout << setfill('0') << setw(2) << hour << ":"
44        << setw(2) << minute << ":"
45        << setw(2) << second << endl;
46 }
47 
48 Clock reset()
49 
50 {
51        return Clock(0, 0, 0);
52 }
53 int main()
54 {
55        Clock c1(12, 0, 5);
56        c1.show_time();
57        c1 = reset();
58        c1.show_time();
59        Clock c2(c1);
60        c2.set_time(6);
61        c2.show_time();
62 }

运行结果以及更换数据元素后的实验结果

 实验4

 1 #include <iostream>
 2    class X
 3 {
 4        public:
 5               X();
 6               ~X();
 7               X(int m);
 8               X(const X& obj);
 9               X(X&& obj)  noexcept; 
10               void show() const;
11               
12        private:
13            int data;
14            
15 };
16    
17    X::X(): data{42}
18    {
19        std::cout<<"default constructor called.\n";
20    }
21    X::~X()
22    {
23        std::cout<<"destructor called.\n";
24    }
25    X::X(int m): data{m} 
26    {
27     std::cout<<"constructor called.\n";
28    }
29    X::X(const X& obj): data{obj.data}

30    {
31     std::cout<<"copy constructor called.\n";
32    }
33    X::X(X&& obj) noexcept:data{obj.data} 
34    {
35     std::cout<<"move constructor called.\n";
36    }
37        void X::show() const 
38 {
39    std::cout<<data<<std::endl;
40 }
41       int main() 
42       {
43           X x1; 
44           x1.show();
45            X x2{2049};
46           x2.show(); 
47           X x3{x1}; 
48           x3.show();
49           X x4{ std::move(x2) }; 
50           x4.show();
51      }

运行结果以及修改元素后的运行结果

   分析

     1.第43行，程序自动调用类中的X（）默认构造函数。45行中，调用了X（int m）的构造函数。47行中，调用了复制构造函数。49行调用了移动构造函数。这些都可以从conmstructor called中可以看出来调用的时候。

     2.程序结束前，系统调用析构函数。

实验5

 1 #include<iostream>
 2 #include<iomanip>
 3 class Rectangle
 4 {
 5     public:
 6         Rectangle(double l=2.0,double w=1.0);
 7         Rectangle(const Rectangle& obj);
 8         ~Rectangle()=default;
 9         double len() const 
10         {
11            return length;
12         }
13         double wide() const 
14         {
15            return width;
16         } 
17         double area() const 
18         {
19            return length*width;
20         }
21         double circumference() const 
22         {
23            return 2*(length+width);
24         }
25         void resize(int times);
26         void resize(int l_times,int w_times);
27     private:
28         double length, width;
29 };
30   Rectangle::Rectangle(double l,double w)
31   {
32       length=l;
33       width=w;
34   }
35   Rectangle::Rectangle(const Rectangle& obj)
36   {
37       length=obj.length;
38       width=obj.width;
39   }
40     void Rectangle::resize(int times)
41 {
42     length*=times;
43     width*=times;
44 }
45     void Rectangle::resize(int l_times,int w_times)
46 {
47     length*=l_times;
48     width*=w_times;
49 }
50 
51 void output(const Rectangle &rect)
52 {
53     using namespace std;
54 
55     cout<<"矩阵信息:\n";
56     cout<< fixed << setprecision(2);
57     cout<<std::left<<setw(8)<<"长:"<<std::right<<setw(8)<<rect.len()<<endl;
58     cout<<std::left<<setw(8)<<"宽:"<<std::right<<setw(8)<<rect.wide()<<endl;
59     cout<<std::left<<setw(8)<<"面积:"<<std::right<<setw(8)<<rect.area()<<endl;
60     cout<<std::left<<setw(8)<<"周长"<<std::right<<setw(8)<<rect.circumference()<<endl;
61     cout<<endl;
62 }
63 
64 int main() 
65 {
66     Rectangle rect1;
67     output(rect1);
68     Rectangle rect2(10, 5);
69     output(rect2);
70     Rectangle rect3(rect1);
71     rect3.resize(2);
72     output(rect3);
73     rect3.resize(5, 2);
74     output(rect3);
75 }

运行结果