Introduction to Exceptions

Part of the Logic & Flow section of Coddy's C++ journey — lesson 48 of 56.

When programs run, things don't always go as planned. Files might not exist, users might enter invalid input, or calculations might fail. These unexpected situations are called exceptions, and they can cause your program to crash if not handled properly.

Exception handling is a programming technique that allows you to gracefully respond to errors instead of letting your program terminate unexpectedly. Rather than crashing when something goes wrong, you can catch these errors and decide how to handle them - whether that's showing a helpful message to the user, trying an alternative approach, or safely shutting down.

Consider what happens when you try to convert invalid text to a number, or when you attempt to access a file that doesn't exist. Without exception handling, these situations would cause your program to stop abruptly. With proper error handling, you can anticipate these problems and provide a smooth user experience even when things go wrong.

C++ provides a structured way to handle exceptions using the try-catch mechanism, which allows you to separate your normal program logic from your error-handling code. This makes your programs more robust and user-friendly, essential qualities for any reliable software.

Cheat sheet

Exception handling allows programs to gracefully respond to errors instead of crashing unexpectedly. C++ uses the try-catch mechanism to handle exceptions:

try {
    // Code that might throw an exception
} catch (exception_type e) {
    // Handle the exception
}

This separates normal program logic from error-handling code, making programs more robust and user-friendly.

Try it yourself

This lesson doesn't include a code challenge.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Logic & Flow

2Vectors (Dynamic Arrays)

Introducing std::vector Creating a Vector Adding Elements Accessing Elements Vector Size Iterating with a For Loop Range-Based For Loop Removing Elements Recap - Vector Operations

5Project: Inventory Tool

Project Setup Adding and Updating Items

Checking Stock

Removing Stock

Printing the Inventory Report

8Basic Error Handling

Introduction to ExceptionsThe 'try' and 'catch' Blocks The 'throw' Keyword Different Exception Types The Catch-All Handler Recap - Safe Division

3Project: Task List Tool

Project Overview Adding a Task

Viewing Tasks

Removing a Task

Finishing the Tool

6Sets (Unique Elements)

Introducing std::set Create Set & Add Elements Checking for Elements Removing Elements Iterating Over a Set Recap - Unique Numbers

9Final Challenges

Vector Data Filtering Map Value Search Pointer and Dynamic Array