第三次实验

四.实验
4-11
#include<iostream> 
using namespace std;
class R{
    public:
        R(double a,double b);
        double area();
    private:
        double l,w;
};
 R::R(double a,double b){
     l=a;
     w=b;
 }
 double R::area(){
 return l*w;}
 int main()
 {
     double l,w,s;
     cout<<"请输入长和宽：";
     cin>>l>>w;
     R c(l,w) ;
     s=c.area();
     cout<<"矩形的面积为："<<s<<endl;
     return 0;
 }
4-20

#include<iostream>
using namespace std;
class complex{
	public:
	  complex(double a,double b);
	  void add(complex c2);
	  void show();
	private:
	  double real,imaginary;
		
};
complex::complex(double a,double b){
	real=a;
	imaginary=b;
}
void complex::add(complex c2){
	real+=c2.real;
	imaginary+=c2.imaginary;
}
void complex::show(){
	cout<<real<<"+";
	cout<<imaginary<<"i"<<endl;
}
int main()
{
	complex c1(3,5);
	complex c2(4.5,0);
	c1.add(c2);
	c1.show();
	return 0;
}

五.实验结论
通过本次实验，了解了构造函数，复制构造函数，析构函数的用法以及加深了对类和对象的体会，实验中对照课本例题进行理解和修改，感觉掌握的不是很好。4-20例题输入c2=4.5还不能编译不知道是为什么。