Welcome to the realm of exceptions in JavaScript functions! In this journey, you will learn how exceptions operate within a function, how to handle these unexpected events using try-catch, and how to rethrow exceptions. We will also examine the consequences of unhandled exceptions. This knowledge will aid you in crafting robust JavaScript functions.

We will delve into the workings of exceptions inside functions. Exceptions can be thrown from any location in a function using the throw keyword. For instance:

In this scenario, an exception is thrown if the baseID is invalid. An exception interrupts normal function execution until it is caught.

Alternatively, we could throw new Error("Invalid ID!"); - in that case, the error message when catching the error will be accessible in the message field.

The common pattern in functions is catching an exception, implementing a handling action (like logging or processing the error case), and then optionally rethrowing it if we need to allow the exception to signal an issue to the function's caller. See the following example: