2023 4 27

 2 #include <iostream>
 3 #include <string>
 4 using namespace std;
 5 class Shape
 6 {
 7     virtual void setvalues() = 0;
 8     virtual void floatarea() = 0;
 9 };
10 class rectangle:public Shape
11 {
12 public:
13     void setvalues()
14     {
15         cout<<"请输入矩形的底和高："<<endl;
16         cin>>x>>y;
17     }
18     void floatarea()
19     {
20         cout<<"矩形的面积为："<<x*y<<endl;
21     }
22     float x;
23     float y;
24 };
25 class arctangle:public Shape
26 {
27 public:
28     void setvalues()
29     {
30         cout<<"请输入三角形的底和高："<<endl;
31         cin>>x>>y;
32     }
33     void floatarea()
34     {
35         cout<<"三角形的面积为："<<x*y/2<<endl;
36     }
37     float x;
38     float y;
39 };
40 class square:public Shape
41 {
42 public:
43     void setvalues()
44     {
45         cout<<"请输入正方形的边长："<<endl;
46         cin>>x;
47     }
48     void floatarea()
49     {
50         cout<<"正方形的面积为："<<x*x<<endl;
51     }
52     float x;
53 };
54 class circle:public Shape
55 {
56 public:
57     void setvalues()
58     {
59         cout<<"请输入圆形的半径："<<endl;
60         cin>>r;
61     }
62     void floatarea()
63     {
64         cout<<"圆形的面积为："<<3.1415*r*r<<endl;
65     }
66     float r;
67 };
68 void test()
69 {
70     rectangle r;
71     arctangle a;
72     square s;
73     circle c;
74     r.setvalues();
75     a.setvalues();
76     s.setvalues();
77     c.setvalues();
78     if(r.x<=0||r.y<=0||a.x<=0||a.y<=0||s.x<=0||c.r<=0)
79     {
80         cout<<"Set Value Error!"<<endl;
81         exit(0);
82     }
83     r.floatarea();
84     a.floatarea();
85     s.floatarea();
86     c.floatarea();
87 }
88 int main()
89 {
90     test();
91     return 0;
92 }

#include <iostream>
using namespace std;
//利用多态，实现计算器
//多态的好处
//1、组织结构清晰
//2、可读性强
//3、对于前期和后期扩展以及维护性高
class AbstractCalculator
{
public:
    int m_Num1;
    int m_Num2;
    virtual int getResult()
    {
        return 0;
    }
};
class AddCalculate : public AbstractCalculator
{
    int getResult()
    {
        return m_Num1 + m_Num2;
    }
};
class SubCalculate : public AbstractCalculator
{
    int getResult()
    {
        return m_Num1 - m_Num2;
    }
};
class MulCalculate : public AbstractCalculator
{
    int getResult()
    {
        return m_Num1 * m_Num2;
    }
};
void test()
{
    //创建加法计算器
    AbstractCalculator *abc = new AddCalculate;
    abc->m_Num1 = 10;
    abc->m_Num2 = 10;
    cout<<abc->m_Num1<<" + "<<abc->m_Num2<<" = "<<abc->getResult()<<endl;
    delete abc;
    //创建加法计算器
    abc = new SubCalculate;
    abc->m_Num1 = 10;
    abc->m_Num2 = 10;
    cout<<abc->m_Num1<<" - "<<abc->m_Num2<<" = "<<abc->getResult()<<endl;
    //创建乘法计算器
    abc = new MulCalculate;
    abc->m_Num1 = 10;
    abc->m_Num2 = 10;
    cout<<abc->m_Num1<<" * "<<abc->m_Num2<<" = "<<abc->getResult()<<endl;
}
int main()
{
    test();
    return 0;
}