实验任务2
源代码：
1 #include <iostream>
2 using std::cout;
3 using std::endl;
4
5 class Point
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 cout << "constructor called." << endl;
21 }
22
23 Point::Point(const Point& p): x{p.x}, y{p.y}
24 {
25 cout << "copy constructor called." << endl;
26 }
27 void Point::show() const
28 {
29 cout << "(" << x << ", "
30 << y << ")" << endl;
31 }
32 int main()
33 {
34 Point p1(4, 5);
35 p1.show();
36 Point p2 = p1;
37 p2.show();
38 Point p3{p2};
39 p3.show();
40 cout << p3.get_x() << endl;
41 }
运行结果：
修改数据后运行结果
实验任务3
源代码：
1 #include <iostream>
2 #include <iomanip>
3 using std::cout;
4 using std::endl;
5 class Clock
6 {
7 public:
8 Clock(int h = 0, int m = 0, int s = 0);
9 Clock(const Clock& t);
10 ~Clock() = default;
11 void set_time(int h, int m = 0, int s = 0);
12 void show_time() const;
13 private:
14 int hour, minute, second;
15 };
16
17 Clock::Clock(int h, int m, int s): hour{h}, minute{m}, second{s}
18 {
19 cout << "constructor called" << endl;
20 }
21 Clock::Clock(const Clock& t): hour{t.hour}, minute{t.minute},
22 second{t.second}
23 {
24 cout << "copy constructor called" << endl;
25 }
26 void Clock::set_time(int h, int m, int s)
27 {
28 hour = h;
29 minute = m;
30 second = s;
31 }
32 void Clock::show_time() const
33 {
34 using std::setw;
35 using std::setfill;
36 cout << setfill('0') << setw(2) << hour << ":"
37 << setw(2) << minute << ":"
38 << setw(2) << second << endl;
39 }
40
41 Clock reset()
42 {
43 return Clock(0, 0, 0);
44 }
45 int main()
46 {
47 Clock c1(12, 0, 5);
48 c1.show_time();
49 c1 = reset();
50 c1.show_time();
51 Clock c2(c1);
52 c2.set_time(6);
53 c2.show_time();
54 }
运行结果：
更改数据后运行结果：
实验任务4
源代码：
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 private:
12 int data;
13 };
14 X::X() : data{ 42 }
15 {
16 std::cout << "default constructor called.\n";
17 }
18 X::~X()
19 {
20 std::cout << "destructor called.\n";
21 }
22 X::X(int m) : data{ m }
23 {
24 std::cout << "constructor called.\n";
25 }
26 X::X(const X& obj) : data{ obj.data }
27 {
28 std::cout << "copy constructor called.\n";
29 }
30 X::X(X&& obj) noexcept : data{ obj.data }
31 {
32 std::cout << "move constructor called.\n";
33 }
34 void X::show() const
35 {
36 std::cout << data << std::endl;
37 }
38 int main() {
39 X x1;
40 x1.show();
41 X x2{ 2049 };
42 x2.show();
43 X x3{ x1 };
44 x3.show();
45 X x4{ std::move(x2) };
46 x4.show();
47 }
运行结果：
分析：
line39调用默认构造函数；line41调用构造函数；line43调用复制构造函数；line45调用移动构造函数；
line47析构函数被调用了4次，销毁和清理了对象x1、x2、x3、x4占用的资源。
实验任务5
源代码：
1 #include <iostream>
2 #include <iomanip>
3
4 class Rectangle
5 {
6 public:
7 Rectangle();
8 Rectangle(double l , double w );
9 Rectangle(const Rectangle& rect);
10 ~Rectangle()=default;
11 double len()const{return length;}
12 double wide()const { return width; }
13 double area()const { return length * width; }
14 double circumference()const { return 2 * length + 2 * width; }
15 void resize(int times);
16 void resize(int l_times, int w_times);
17 private:
18 double length, width;
19 };
20 Rectangle::Rectangle()
21 {
22 length = 2.0;
23 width = 1.0;
24 }
25 Rectangle::Rectangle(double l, double w)
26 {
27 length = l;
28 width = w;
29 }
30 Rectangle::Rectangle(const Rectangle& rect)
31 {
32 length = rect.length;
33 width = rect.width;
34 }
35 void Rectangle::resize(int times)
36 {
37 length *= times;
38 width *= times;
39 }
40 void Rectangle::resize(int l_times, int w_times)
41 {
42 length *= l_times;
43 width *= w_times;
44 }
45
46
47 void output(const Rectangle& rect)
48 {
49 using namespace std;
50 cout << "矩形信息: \n";
51 cout << "长: " << fixed << setprecision(2) << rect.len() << endl;
52 cout << "宽: " << fixed << setprecision(2) << rect.wide() << endl;
53 cout << "面积: " << fixed << setprecision(2) << rect.area() << endl;
54 cout << "周长: " << fixed << setprecision(2) << rect.circumference() << endl;
55 }
56 int main()
57 {
58 Rectangle rect1;
59 output(rect1);
60 Rectangle rect2(10, 5);
61 output(rect2);
62 Rectangle rect3(rect1);
63 rect3.resize(2);
64 output(rect3);
65 rect3.resize(5, 2);
66 output(rect3);
67 }
运行结果：
标签：const,int,times,width,length,实验,Rectangle From： https://www.cnblogs.com/dyb20030328/p/16738892.html