What is exception handling in C++?

Table of Contents

• Introduction
• Basics of Exception Handling
  • How Exception Handling Works
• Example of Exception Handling
• Detailed Explanation
• Practical Examples
  • Example 1: Exception Handling in Functions
  • Example 2: Multiple Catch Blocks
• Conclusion

Introduction

Exception handling in C++ is a mechanism that allows programs to handle runtime errors and exceptional situations in a structured and controlled manner. It helps maintain the flow of the program and ensures that errors are managed gracefully without crashing the application. This guide explains the basics of exception handling in C++, including the use of try, catch, and throw keywords, and provides practical examples.

Basics of Exception Handling

In C++, exception handling is used to detect and manage runtime errors and unexpected situations. The basic components of exception handling are:

• try Block: Contains code that might throw an exception. It is the code that you want to monitor for errors.
• catch Block: Catches and handles exceptions thrown by the try block. You can have multiple catch blocks to handle different types of exceptions.
• throw Keyword: Used to signal that an exception has occurred. It transfers control to the nearest catch block.

How Exception Handling Works

1. Throwing Exceptions: When an error or exceptional situation occurs, the throw keyword is used to create an exception object and pass it to the catch block.
2. Catching Exceptions: The catch block receives the thrown exception and handles it. The program execution resumes after the catch block completes.
3. Unwinding the Stack: If an exception is thrown, the stack is unwound, and destructors for objects are called until a matching catch block is found.

Example of Exception Handling

Basic Example:

Detailed Explanation

1. Throwing Exceptions: The throw keyword is used to throw an exception. In the example, throw std::runtime_error("Division by zero is not allowed"); creates an exception object and throws it.

2. Catching Exceptions: The catch block catches the exception and handles it. The type of exception is matched with the type specified in the catch block. In the example, catch (const std::runtime_error& e) handles exceptions of type std::runtime_error.

3. Exception Handling Hierarchy: C++ provides a hierarchy of exception classes, and you can catch exceptions by base class types to handle multiple derived exception types.

   Example:

Practical Examples

Example 1: Exception Handling in Functions

Example 2: Multiple Catch Blocks

Conclusion

Exception handling in C++ is a robust mechanism for managing runtime errors and exceptional conditions. By using try, catch, and throw, you can handle errors gracefully, ensuring that your program can continue to run or terminate cleanly. Understanding how to use these features effectively helps in writing reliable and maintainable C++ code.