实验三

#include <iostream>
using namespace std;

class Space
{
	public:
		Space();
		Space(double x0, double y0);
		Space(Space &s0);
		~Space();
		double area()  {return l*w ; }
	
	private:
		double l;
		double w;
};

Space::Space()
{
	cout<<"Constructor(default) is called!"<<endl;
	l=0;
	w=0;
}

Space::Space(double x0, double y0)
{
	cout<<"Constructor is called!"<<endl;
	l=x0;
	w=y0;
}

Space::Space(Space &s0)
{
	cout<<"Copy constructor is called!"<<endl;
	l=s0.l;
	w=s0.w;
}

Space::~Space()
{
	cout<<"Destructor is called!"<<endl;
}

int main()
{
	Space s1;
	cout<<"S="<<s1.area()<<endl;
	
	double x, y;
	cout<<"请输入长和宽:";
	cin>>x>>y;
	Space s2(x, y);
	cout<<"S="<<s2.area()<<endl;
	
	Space s3(s2);
	cout<<"S="<<s3.area()<<endl;
	
	return 0;
}

　　

#include<iostream>
using namespace std;

class Complex
{
    public:
        Complex(double r0,double i0); 
        Complex(double r0);
        void add(Complex &c0); 
        void show(){cout<<i<<'+'<<r<<'i'<<endl;}
        
        
    private:
        double r;//实部 real
        double i;//虚部 imaginary
        
};
 
Complex::Complex(double r0,double i0)
{
    r=r0;
	i=i0;
}
 
Complex::Complex(double r0)
{
    r=r0;
	i=0;
}
 
void Complex::add(Complex &c0)
{
    r+=c0.r;
	i+=c0.i;
}
 
int main()
{
    Complex c1(3,5);
    Complex c2=4.5;
    c1.add(c2);
    c1.show();
    return 0;
}