实验一之5

#include <iostream>
#include <iomanip>

class rectangle{
public:
rectangle(double l=2.00,double w=1.00):length{l },width{w} {};
rectangle(const rectangle& obj):length{obj.length},width{obj.width}{};
~rectangle()=default;
double len() const{return length;}
double wide()const{return width;}
double area()const{return length*width;}
double circumference() const{return (length+width)*2;}
void resize (int times);
void resize (int l_times,int w_times);
private:
double length,width;
};
void rectangle::resize(int times){
length*=times;
width*=times;
}
void rectangle::resize(int l_times,int w_times){
length*=l_times;
width*=w_times;
}

void output(const rectangle &rect)
{ using namespace std;
cout << "矩形信息: \n";
cout << fixed << setprecision(2);
cout<<std::left<<setw(8)<<"长："<<rect.len()<<endl;
cout<<std::left<<setw(8)<<"宽:" <<rect.wide()<<endl;
cout<<std::left<<setw(8)<<"面积:" <<rect.area()<<endl;
cout<<std::left<<setw(8)<< "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);
}