实验1

实验1.2

#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(6,1);
    p1.show();
    
    Point p2=p1;
    p2.show();
    
    Point p3{p2};
    p3.show();
    cout<<p3.get_x()<<endl;
}

实验1.3

#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(11,12,5);
    c1.show_time();
    
    c1=reset();
    c1.show_time();
    
    Clock c2(c1);
    c2.set_time(4);
    c2.show_time();
}

实验1.4

#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(); 
}

分析：第32行调用默认构造函数、第35行调用构造函数、第38行调用复制构造函数、第41行调用移动构造函数

析构函数在程序结束时被调用顺序为，x4-x3-x2-x1.

实验1.5

#include <iostream>
#include <iomanip>
class Rectangle{
    public:
        Rectangle(double length=2.0,double wideth=1.0);
        Rectangle(const Rectangle& rect);
        ~Rectangle()=default;
        double len()const;
        double wide()const ; 
        double area()const ;
        double circumference()const ;
        void resize(auto t=1);
        void resize(double l_t=1.0,double w_t=1.0);
        
        
    private:
        double l;double w;double times;double l_times;double w_times;
};
Rectangle::Rectangle(double length,double wideth):l{length},w{wideth}{
}
Rectangle::Rectangle(const Rectangle& rect){
    l=rect.l;
    w=rect.w;

}
void Rectangle::resize(auto t){
    times=t;
    l*=times;
    w*=times;
}
void Rectangle::resize(double l_t,double w_t){
    l_times=l_t;
    w_times=w_t;
    l*=l_times;
    w*=w_times;
}
double Rectangle::len()const{
    
     return l;
}
double Rectangle::wide()const{

     return w;
}
double Rectangle::area()const{
    return l*w;
}
double Rectangle::circumference()const{
    return 2*(l+w);
}
void output(const Rectangle &rect){
    using namespace std;
    cout<<"矩阵信息：\n";
    cout<<fixed<<setprecision(2);
    cout<<"长：    "<<rect.len()<<endl
        <<"宽：    "<<rect.wide()<<endl
        <<"面积：    "<<rect.area()<<endl
        <<"周长：    "<<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);

}