实验一

#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 + "1");
    v1.push_back(s4 + "3");

    cout << "output1: " << endl;
    for (auto item : v1)
        cout << item << endl;

    cout << "output2: ";
    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;
}

#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);
    }

#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(9, 9);
    p1.show();
    Point p2 = p1;
    p2.show();
    Point p3{ p2 };
    p3.show();
    cout << p3.get_x() << endl;
}

#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(13, 13, 13);
    c1.show_time();
    c1 = reset();
    c1.show_time();
    Clock c2(c1);
    c2.set_time(23,59,59);
    c2.show_time();
}

#include<iostream>
class X {
public:
    X();
    ~X();
    X(int m);
    X(const X& obj);
    X(X&& obj) noexcept;
    void show() const;
private:
    int date;
};
X::X() :date{ 42 } {
    std::cout << "default constructor called.\n";
}
X::~X() {
    std::cout << "destructor called.\n";
}
X::X(int m) :date{ m } {
    std::cout << "constructor called.\n";
}
X::X(const X& obj) : date{ obj.date } {
    std::cout << "copy constructor called.\n";
}
X::X(X&& obj) noexcept : date{ obj.date } {
    std::cout << "move constructor called.\n";
}
void X::show() const {
    std::cout << date << 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();
}

 X x1;默认构造函数被编译器自动调用；

X x2{2049};构造函数被编译器自动调用；

X x3{x1};复制构造函数被编译器自动调用；

X x4{ std::move(x2) };移动函数被编译器调用；

运行结束前调用析构函数。

#include<iostream>
#include<iomanip>
class rectangle {
public:
    rectangle();
    rectangle(double l, double w);
    rectangle(const rectangle& rect);
    ~rectangle() {}
    double len() const { return length; }
    double wide() const { return width; }
    double area() const { return length * width; }
    double circumference() const { return 2 * (length + width); }
    void resize(int times);
    void resize(int l_times, int w_times);
private:
    double length, width;
};
rectangle::rectangle() {
    length = 2.0;
    width = 1.0;
}
rectangle::rectangle(double l, double w) {
    length = l;
    width = w;
}
rectangle::rectangle(const rectangle& rect) {
    length = rect.length;
    width = rect.width;
}
void rectangle::resize(int times) {
    length = length * times;
    width = width * times;
}
void rectangle::resize(int l_times, int w_times) {
    length = length * l_times;
    width = width * w_times;
}
rectangle output(const rectangle& rect)
{
    using namespace std;
    cout << "矩形信息：" << endl;
    cout << "长：    " << fixed << setprecision(2) << rect.len() << endl;
    cout << "宽：    " << fixed << setprecision(2) << rect.wide() << endl;
    cout << "面积：  " << fixed << setprecision(2) << rect.area() << endl;
    cout << "周长：  " << fixed << setprecision(2) << rect.circumference() << endl;
    cout << 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);
}