What methods and practices are used to check and prevent errors in code and systems?

The following methods and practices are used to check and prevent errors in code and systems:

• Unit testing — writing tests for individual functions or components to ensure their correct operation.
• Integration testing — checking the interaction between modules.
• Static code analysis — using tools that analyze code without executing it, identifying potential errors, memory leaks, and style violations.
• Dynamic analysis — running code with tools that monitor behavior during execution (e.g., Valgrind for C/C++).
• Code review — collective review of code to identify errors and improve quality.
• Using version control systems — allows tracking changes and quickly reverting in case of errors.
• Exception handling and error checking — in C++ this is try-catch, in C — checking return values of functions.

Example of error handling in C++:

#include <iostream>
#include <stdexcept>

int divide(int a, int b) {
    if (b == 0) {
        throw std::invalid_argument("Division by zero");
    }
    return a / b;
}

int main() {
    try {
        std::cout << divide(10, 0) << std::endl;
    } catch (const std::invalid_argument& e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }
    return 0;
}

This approach helps prevent program crashes and handle errors correctly.