实验三

 1 #include<iostream>
 2 using namespace std;
 3 class Rectangle
 4 {
 5     public:
 6         Rectangle(float len,float wid)
 7         {length=len;
 8          width=wid;
 9         
10         }
11         float getarea()
12         {
13             return length*width;
14             
15         }
16         Rectangle(Rectangle &r)
17         {}//没搞懂哪个地方能用到复制构造函数。。求大神解解惑O(∩_∩)O ，灰常感谢！ 
18         ~ Rectangle() {}
19     private:
20         float length;
21         float width;
22 };
23  int main()
24  {  float x,y;
25     cout<<"输入长和宽"<<endl; 
26     cin>>x >>y;
27      Rectangle rec(x,y);
28      cout<<"矩形面积："<<rec.getarea()<<endl; 
29      return 0;
30  }

 1 #include<iostream>
 2 using namespace std;
 3 class Complex
 4 {
 5 public:
 6     Complex(double r0,double i0)
 7     {
 8         real=r0,imaginary=i0;
 9     };
10     Complex(double r0)
11     {
12         real=r0;
13     }; 
14     Complex(Complex &c0);
15     void add(Complex &c0);
16     void show();
17 private:
18     double real,imaginary;
19 };
20 
21 void Complex::add(Complex &c0)
22 {
23 real+=c0.real,imaginary+=c0.imaginary;
24 }
25 void Complex::show()
26 {
27 cout<<real<<(imaginary>0 ? ‘+‘:‘-‘)<<imaginary<<‘i‘<<endl;
28 }
29 int main()
30 {
31 Complex c1(3,5);
32 Complex c2(4.5);
33 c1.add(c2);
34 c1.show();
35 return 0;
36 }