Select topics to narrow your question pool, then enable Random to jump to a random question matching your filters.

C++ Quiz #146

Destroyed Once or Twice

mediumExceptions

The second Sensor throws from its constructor. How many times does destroyed print, and for which object?

📄 Code

1#include <iostream>
2#include <stdexcept>
3 
4class Sensor {
5public:
6    Sensor(int id) {
7        std::cout << "building " << id << "\n";
8        if (id < 0) {
9            throw std::invalid_argument("bad id");
10        }
11    }
12    ~Sensor() { std::cout << "destroyed\n"; }
13};
14 
15int main() {
16    try {
17        Sensor a(1);
18        Sensor b(-1);
19        std::cout << "both ready\n";
20    } catch (const std::exception& e) {
21        std::cout << "caught: " << e.what() << "\n";
22    }
23    return 0;
24}