- 实验任务二
1 #include<iostream>
2
3 using std::cout;
4 using std::cin;
5 using std::endl;
6 class Point {
7 public:
8 Point(int x0 = 0, int y0 = 0);
9 Point(const Point& p);
10 ~Point() = default;
11
12 int get_x()const { return x; }
13 int get_y()const { return y; }
14 void show()const;
15 private:
16 int x, y;
17
18 };
19 //point 类的实现
20 //构造带有默认形参值的函数
21 Point::Point(int x0, int y0) :x{x0}, y{y0}{
22 cout << "constructor called." << endl;
23 }
24 //复制构造函数
25 //参数必须是自身对象的引用类型
26 Point::Point(const Point& p) :x{ p.x }, y{ p.y }{
27 cout << "copy constructor called." << endl;
28 }
29 void Point::show()const {
30 cout << "(" << x << "," << y << ")" << endl;
31 }
32 int main()
33 {
34 int x, y;
35 cin >> x >> y;
36 Point p1(x, y);
37 p1.show();
38 Point p2 = p1; //复制构造函数被调用
39 p2.show();
40 Point p3{ p2 };//复制构造函数被调用
41 p3.show();
42 cout << p3.get_x() << endl;
43 }
- 实验任务三
1 #include<iostream>
2 #include<iomanip>
3 using std::cout;
4 using std::endl;
5 //定义时钟类型clock
6 class Clock {
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 , int s );
12 void show_time()const;
13 private:
14 int hour, minute, second;
15 };
16 Clock::Clock(int h, int m, int s) :hour{ h }, minute{ m }, second{ s }{
17 cout << "constructor called."<< endl;
18 }
19 Clock::Clock(const Clock& t) :hour{ t.hour }, minute{ t.minute }, second{ t.second }{
20 cout << "copy constructor called." << endl;
21 }
22 void Clock::set_time(int h, int m=0, int s=0) {
23 hour = h;
24 minute = m;
25 second = s;
26 }
27 void Clock::show_time()const {
28 using std::setw;
29 using std::setfill;
30
31 cout << setfill('0') << setw(2) << hour << ":"
32 << setw(2) << minute << ":"
33 << setw(2) << second << endl;
34 }
35 Clock reset() {
36 return Clock(0, 0, 0);
37 }
38 int main()
39 {
40 Clock c1(8,9,4);
41 c1.show_time();
42
43 c1 = reset();
44 c1.show_time();
45
46 Clock c2(c1);//复制构造函数被调用
47 c2.set_time(7, 5);
48 c2.show_time();
49 }
- 实验任务四
1 #include<iostream>
2 //定义一个简单抽象类X
3 class X {
4 public:
5 X();//默认构造函数
6 ~X();//析构函数
7 X(int m);
8 X(const X& obj);//复制构造函数
9 X(X&& obj)noexcept;//移动构造函数
10 void show()const;
11 private:
12 int data;
13 };
14 X::X() :data{ 42 } {
15 std::cout << "default constructor called." << std::endl;
16 }
17 X::~X() {
18 std::cout << "destructor called." << std::endl;
19 }
20 X::X(int m) :data{ m } {
21 std::cout << "constructor called." << std::endl;
22 }
23 X::X(const X& obj) :data{ obj.data } {
24 std::cout << "copy constructor called." << std::endl;
25 }
26 X::X(X&& obj)noexcept :data{ obj.data } {
27 std::cout << "move constructor called." << std::endl;
28 }
29 void X::show()const {
30 std::cout << data << std::endl;
31 }int main()
32 {
33 X x1;//默认构造函数被编译器自动调用
34 x1.show();
35 X x2{ 2049 };//构造函数被编译器自动调用
36 x2.show();
37 X x3{ x1 };//复制构造函数被编译器自动调用
38 x3.show();
39 X x4{ std::move(x2) };//移动构造函数被编译器调用
40 x4.show();
41 }
line33,调用默认构造函数X();
line35,调用构造函数X(int m);
line37,调用复制构造函数X(const X& obj);
line39,调用移动构造函数X(X&& obj)..
析构函数会在对应对象的作用域最后被调用..例如在main里声明了一个类，那么这个类就会在main结束时被调用..
- 实验五
1 #include<iostream>
2 #include<iomanip>
3 class Rectangle {
4 public:
5 Rectangle();
6 Rectangle(double l, double w);
7 Rectangle(const Rectangle& obj);
8 ~Rectangle()=default;
9 double len()const { return length; }
10 double wide()const { return width; }
11 double area() const{ return length * width; }
12 double circumference()const { return 2 * (length + width); }
13 void resize(double times);
14 void resize(double l_times, double w_times);
15 private:
16 double length,width;
17 };
18 Rectangle::Rectangle():length{2.0},width{1.0}{}
19 Rectangle::Rectangle(double l,double w):length{l},width{w}{}
20 Rectangle::Rectangle(const Rectangle& obj):length{obj.length},width{obj.width}{}
21 void Rectangle::resize(double times)
22 {
23 length *= times;
24 width *= times;
25 }
26 void Rectangle::resize(double l_times, double w_times)
27 {
28 length *= l_times;
29 width *= w_times;
30 }
31 void output(const Rectangle& rect) {
32 using namespace std;
33 cout << "矩阵信息： " << endl;
34 cout<<fixed << setprecision(2);
35 cout.width(8);
36 cout.setf(ios::left);
37 cout << "长：" <<rect.len() << endl;
38 cout.width(8);
39 cout.setf(ios::left);
40 cout << "宽：" << rect.wide() << endl;
41 cout.width(8);
42 cout.setf(ios::left);
43 cout << "面积：" << rect.area() << endl;
44 cout.width(8);
45 cout.setf(ios::left);
46 cout << "周长：" <<rect.circumference() << endl;
47 cout << endl;
48 }
49 int main()
50 {
51 Rectangle rect1;
52 output(rect1);
53 Rectangle rect2(10, 5);
54 output(rect2);
55 Rectangle rect3(rect1);
56 rect3.resize(2);
57 output(rect3);
58 rect3.resize(5, 2);
59 output(rect3);
60 }
标签：const,Point,int,double,实验,Rectangle,构造函数 From： https://www.cnblogs.com/zzzys/p/16740715.html