第一次实验报告

实验报告

实验任务1

(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 << "output1: " << endl;
	for (auto item : v1)
		cout << item << endl;
	cout << "ouput2: ";
	for (auto p = v1.begin(); p != v1.end(); ++p)
		cout << *p << endl;
	cout << "output3: " << 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;


}

(2)

#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);
}

实验任务2

代码如下：

#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(7, 8);
		p1.show();
		Point p2 = p1;
		p2.show();
		Point p3{ p2 };
		p3.show();
		cout << p3.get_x() << endl;
	}

实验任务3

代码如下：
时间修改为：10：12：5 & 7：0：0

#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(10, 12, 5);
	c1.show_time();
	c1 = reset(); 
	c1.show_time();
	Clock c2(c1);
	c2.set_time(7);
	c2.show_time();
}

运行截图如下：

实验任务4

代码如下：

#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();
}

说明如下：

1. x1.show();
   调用默认构造函数;
2. x2.show();
   调用构造函数；
3. X x3{ x1 };
   调用复制构造函数;
4. X x4{ std::move(x2) };
   调用移动构造函数；

实验任务5

代码如下：

#include <iostream>
#include <iomanip>
class Rectangle {
public:
	Rectangle();
	Rectangle(double length,double width);
	Rectangle(Rectangle& rect);
	~Rectangle();


	double len() const { return length; }
	double wide() const { return width; }
	double area() const { return width * length; }
	double circumference() const { return (length + width) * 2; }
	void resize(double times);
	void resize(double length_times, double width_times);

private:
	double length, width;

};


Rectangle::Rectangle() :length { 2.0 },width{ 2.0 }{}
Rectangle::Rectangle(double l, double w): length{ l }, width{ w } {}
Rectangle::Rectangle(Rectangle & rect) : length{ rect.length }, width{ rect.width } {}
Rectangle::~Rectangle() {}

 void Rectangle::resize(double times)
{
	 length = length * times;
	 width = width * times;
 }
 void Rectangle::resize(double length_times, double width_times)
 {
	 length = length * length_times;
	 width = width * width_times;
 }





 void output(const Rectangle& rect) {
	 using namespace std;
	 cout << "矩形信息: \n";
	 cout << fixed << setprecision(2); 
	 cout << setw(2) <<"长度为：" << rect.len() << endl;
	 cout << setw(2) << "宽度为：" << rect.wide() << endl;
	 cout << setw(2) << "周长为：" << rect.circumference() << endl;
	 cout << setw(2) << "面积为： " << rect.area() << 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);
}

实验总结

本次实验我有以下感悟：

1. 我更加深刻的理解了类与对象的意义和其具体的运用方法
2. 反思了格式和书写以及使用方法不对的相关报错