What is the exception handling mechanism in C++?

The exception handling mechanism in C++ is a way to catch and handle any unexpected events that occur within a program. When an exception event occurs, the mechanism will interrupt the current flow of the program and hand over control to the exception handling code for appropriate handling.

The exception handling mechanism in C++ is implemented through several key words and statements.

1. try: Used to indicate a code block that may throw an exception. When an exception occurs, the program will search for the nearest catch block to handle the exception starting from where the exception occurred.
2. throw: Used to throw exceptions in a code block. It can throw any type of data, typically an object of an exception class.
3. catch: Used for capturing and handling thrown exceptions. Multiple catch blocks can be defined to handle different types of exceptions. After an exception is caught, the program will continue executing the code following the catch block.
4. std::exception is a base exception class defined in the C++ standard library, used to derive other exception classes. It includes common exception information and methods, allowing for the creation of custom exception classes by inheriting from it.

By defining your own exception class using these keywords and statements, you can use try-catch blocks in your code to catch and handle exceptions. This can improve the stability and reliability of the program, allowing for appropriate handling of exceptions to prevent the program from crashing or exhibiting unpredictable behavior.