Exceptions (Try...Catch)

Relax. We'll talk through this in plain words — no textbook voice.

Exception handling lets you gracefully deal with error situations that can occur while a program is running. In cases like a missing file, invalid input, or dividing by zero, you can stop the whole program from crashing using try, throw, catch.

cpp

#include <iostream>
using namespace std;

int main() {
    try {
        int age = 15;

        if (age < 18) {
            throw string("You must be at least 18 years old.");
        }

        cout << "Access granted.";
    } catch (string message) {
        cout << "Access denied: " << message;
    }
    return 0;
}

try contains the logic that could error out. If age doesn't meet the minimum, throw fires off an error message, and catch handles it.

You should see

Access denied: You must be at least 18 years old.

Info

Exceptions are meant for expected error flows. You shouldn't write every ordinary condition check as an exception.

Easy traps

If the type you throw doesn't match the type the catch expects, the catch won't catch it.