C++ — Exceptions

Basic try-catch

#include <iostream>
#include <stdexcept>

int main() {
    try {
        throw std::runtime_error("Something went wrong");
    } catch (const std::exception& e) {
        std::cout << "Error: " << e.what() << std::endl;
    }
}

Custom exceptions

class InsufficientFunds : public std::exception {
    double amount;
public:
    InsufficientFunds(double a) : amount(a) {}
    const char* what() const noexcept override {
        return "Insufficient funds";
    }
    double getAmount() const { return amount; }
};

Multiple catch blocks

try {
    // code
} catch (const std::out_of_range& e) {
    std::cout << "Out of range" << std::endl;
} catch (const std::exception& e) {
    std::cout << "General: " << e.what() << std::endl;
} catch (...) {
    std::cout << "Unknown error" << std::endl;
}

Exception specifications

void safeFunction() noexcept {
    // Promise not to throw
}

void riskyFunction() {
    throw std::runtime_error("Error");
}

Mini Practice

Write C++ code that:

1. Uses try-catch for error handling
2. Creates a custom exception class
3. Handles multiple exception types
4. Uses noexcept

Up Next

In the next lesson, you'll learn about File I/O — reading and writing files.