135.异常与类继承

Posted 2020-10-29 喵小喵~

 1 #include <iostream>
 2 using namespace std;
 3 
 4 //如果产生继承,子类的对象也可以被父类捕获.因为子类内部包含父类对象
 5 class outerror
 6 {
 7 public:
 8 };
 9 
10 class newerror:public outerror
11 {
12 public:
13 };
14 
15 class myclass
16 {
17 private:
18     int *p;
19     int n;
20 
21 public:
22     myclass() :p(nullptr), n(0)
23     {
24         
25     }
26 
27     myclass(int i) 
28     {
29         if (i <= 0)
30         {
31             throw newerror();
32         }
33 
34         p = new int[i];
35         for (int j = 0; j < i; j++)
36         {
37             p[j] = j;
38         }
39     }
40 
41     int operator[](int num)
42     {
43         if (num < 0)
44         {
45             throw newerror();
46         }
47 
48         if (num < 0 || num >= n - 1 || p == nullptr)
49         {
50             throw newerror();
51         }
52 
53         if (p == nullptr)
54         {
55             throw newerror();
56         }
57         return p[num];
58     }
59 };
60 
61 void main()
62 {
63     try
64     {
65         myclass my1(1);
66         cout << my1[4];
67     }
68     catch (outerror e)
69     {
70         cout << "outerror e" << endl;
71     }
72     catch (newerror e)
73     {
74         cout << "newerror e" << endl;
75     }
76     
77     
78 
79     cin.get();
80 }