Error Handling Inside Functions Quiz Quiz

Assess your understanding of error handling within functions, including common techniques, best practices, and exception scenarios. This quiz helps solidify your grasp on controlling function behavior when encountering errors and unexpected inputs.

1. Catching Exceptions Locally

   When a function contains a try-catch block to handle potential division by zero, what is the main benefit of handling the exception locally within the function?

   1. The function is no longer required to return any value.
   2. The function can prevent program termination by resolving or logging errors close to their source.
   3. This guarantees the function will always return the correct result even if an error occurs.
   4. It makes the function automatically faster during execution.

   Explanation: Catching exceptions within a function allows the error to be managed or logged locally, preventing unhandled exceptions that could terminate the program. It does not guarantee correctness after an error occurs, so option two is incorrect. Local error handling does not inherently speed up execution, making option three inaccurate. Functions may still need to return values even when handling errors, so option four is misleading.

2. Propagating Errors Upward

   Why might a function choose to re-raise an error instead of handling it completely inside the function?

   1. To eliminate the need for calling code to ever use its own try-catch blocks.
   2. To allow calling code to decide on appropriate action based on broader context.
   3. Because the function cannot contain any type of error handling mechanism.
   4. Because re-raising errors will automatically fix the issue in the function.

   Explanation: Re-raising errors allows higher-level code that called the function to apply context-specific handling, such as user feedback or resource cleanup. Option two is wrong because functions can have their own error handling. Option three is inaccurate because re-raising does not remove the usefulness of error handling in calling code. Option four is incorrect since re-raising does not solve errors; it simply passes them on.

3. Returning Error Codes

   A function sometimes returns an error code (like -1 or null) instead of throwing an exception. Which is a potential drawback of this approach?

   1. Error codes can be accidentally ignored, resulting in hidden issues in the program.
   2. All programming languages require exceptions instead of error codes.
   3. Error codes prevent the function from ever executing successfully.
   4. The approach always crashes the entire application immediately.

   Explanation: Returning error codes poses the risk that calling code may not check for them, leading to subtle bugs or undefined behavior. Option two is wrong; the function can still work normally when successful. Option three is inaccurate—some languages use error codes, while others prefer exceptions. Option four is untrue because returning error codes does not, by itself, cause the application to crash.

4. Default Values in Error Situations

   If a function returns a default value when an error is caught, such as zero when an input is invalid, what is a potential risk of this practice?

   1. This enforces strict type safety in all circumstances.
   2. The program will immediately stop executing due to the default value.
   3. It may produce misleading results that go undetected by the calling code.
   4. It guarantees the function will never have side effects.

   Explanation: Returning a default value might hide the fact that an error occurred, leading to logical errors or incorrect output that is not easily traced by the caller. Option two is incorrect since this approach does not necessarily enforce type safety. Option three is wrong, as side effects may still happen elsewhere in the function. Option four misstates the effect—the program will not stop just because a default value is returned.

5. Custom Error Types in Functions

   What is the advantage of defining custom error types for a function's specific failures (e.g., InvalidParameterError)?

   1. It allows precise identification of the error source for targeted exception handling in calling code.
   2. Using custom errors means the function does not need to document its expected errors.
   3. Custom error types remove the need for testing the function.
   4. It forces all errors in the program to be identical.

   Explanation: Custom error types provide detailed information about the specific failure, making targeted exception handling possible for functions with varied error conditions. Option two is incorrect because custom errors enhance, not eliminate, diversity of error types. Documenting expected errors remains important even with custom errors, so option three is wrong. Option four is false, as proper testing is still required regardless of error handling style.