Custom Exception Class in C++

1#include <iostream>
2#include <exception>
3#include <string>
4using namespace std;
5
6// Custom exception class
7class MyException : public exception {
8private:
9    string message;
10
11public:
12    MyException(const string& msg) : message(msg) {}
13    
14    const char* what() const noexcept override {
15        return message.c_str();
16    }
17};
18
19class AgeException : public exception {
20private:
21    int age;
22
23public:
24    AgeException(int a) : age(a) {}
25    
26    const char* what() const noexcept override {
27        if (age < 0) {
28            return "Age cannot be negative";
29        } else if (age > 150) {
30            return "Age is unrealistic";
31        }
32        return "Invalid age";
33    }
34    
35    int getAge() const { return age; }
36};
37
38void checkAge(int age) {
39    if (age < 0 || age > 150) {
40        throw AgeException(age);
41    }
42    cout << "Valid age: " << age << endl;
43}
44
45int main() {
46    try {
47        checkAge(25);
48        checkAge(-5);
49    } catch (const AgeException& e) {
50        cout << "AgeException caught: " << e.what() << endl;
51    }
52    
53    try {
54        throw MyException("This is a custom exception");
55    } catch (const MyException& e) {
56        cout << "\nCustom exception: " << e.what() << endl;
57    }
58    
59    return 0;
60}