guan34523

#include <iostream>
#include <string>
using namespace std;
class Square{
	double side,area;
	public:
		Square(){
			side=0;area=0;
		}
		Square(double a){
			if(a<0) throw -1;
			side=a;area=a*a;
		}
		void print(){
			cout<<"Square: side= "<<side<<"area= "<<area<<"\n";
		}
		Square& set_side(double a){
			if(a<0) throw -1;
			side=a;area=a*a;
			return *this;
		}
};
int main(){
	Square s1;
	s1.print();
	s1.set_side(2);
	s1.print();

	Square s2(2);
	try{
		s2.set_side(-555);
	}
	catch(...){
		cerr<<"Wyjatek\n";
	}
	try{
		Square s3(-5);
	}
	catch(...){
		cerr<<"Wyjatek\n";
	}
	return 0;
}