实验1 类和对象(1)

实验五
#include <iostream>
#include <iomanip>
class Rectangle
{
public:
    Rectangle();
    ~Rectangle();
    Rectangle(double l,double w);
    Rectangle( const Rectangle& rect);
    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(double times);
    void resize(double l_times, double w_times);
private:
    double length,width;
};
void Rectangle::resize(double times)
{
    length *=times;
    width *= times;
}
void Rectangle::resize(double l_times, double w_times)
{
    length *= l_times;
    width *= w_times;
}
Rectangle::Rectangle():length{2.0},width{1.0}{}
Rectangle::~Rectangle(){}
Rectangle::Rectangle(double l,double w):length{l},width{w}{}
Rectangle::Rectangle(const Rectangle& rect):length{rect.length},width{rect.width}{}
void output( const Rectangle &rect)
{
    using namespace std;
    
    cout << "矩阵信息: \n";
    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);
}

实验一（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;
 } 

实验一（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);
 } 

实验二

#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(2, 3);
    p1.show();
    Point p2 = p1;
    p2.show();
    Point p3{p2};
    p3.show();
    cout << p3.get_x() << endl;
 } 

 

 

实验三

#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(12, 0, 5);
    c1.show_time();
    c1 = reset();
    c1.show_time();
    Clock c2(c1);
    c2.set_time(6); 
    c2.show_time();
}

 

 

实验四

#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();
}
 
 

x1调用了默认构造函数；

x2调用构造函数；

x3调用复制构造函数;

x4调用移动构造函数

析构函数最后调用，之后对x1,x2,x3,x4进行销毁。