C++ handling unanticipated errors

I need to learn C++ basics for a research project, and I'm experimenting with error/exception handling. I did use the `throw` command successfully to anticipate on events that might occur (like divide by zero), but I cannot figure out how to catch unanticipated exceptions. Take this example code: ``` #include <iostream> #include <exception> #include <stdexcept> using namespace std; void arrayOutOfBound() { int a[3] = {1, 2, 3}; try { cout << "This should not display: " << a[5] << endl; } catch(runtime_error &e) /* catch(exception &e) // also does not work */ { cout << "Error: " << e.what() << endl; } } int main() { arrayOutOfBound(); } ``` I guess I have to use `throw` statements somewhere, but suppose I really did not know that `a[5]` wouldn't work (or the user entered this index and I did not check for the array size), then how can I prevent the program from crashing? (as this happens in the Visual C++ Express 2010 debugger) Note: if I would do `try { int result = a[5]; }` first, outside the block, and try to use `cout << result` at the end, the program does not compile. The compiler is trying to help me, but therefore I cannot try the exception handling.