Error code
An error code is a numerical or alphanumerical value that represents the status or outcome of an operation in a program. Unlike exceptions, which interrupt the flow of a program, error codes are returned as the result of a function or method call to indicate success, failure, or some specific condition. Programs that rely on error codes require explicit checks after each operation to determine whether it was successful and to decide how to proceed based on the returned error code.
When to Use Error Codes and Exceptions
When to Use Error Codes and Exceptions
HTTP Stack
In the HTTP, status codes serve as a standardized way of communicating the result of a client’s request to a server. These status codes are well-defined, universally understood, and cover a broad range of scenarios from success (
200 OK) to client errors (404 Not Found) and server errors (500 Internal Server Error). Using status codes in HTTP is important for interoperability, as multiple clients and servers across different platforms and languages interact with each other.Within Your Programs
In contrast, within your own program, using exceptions over error codes can be more beneficial for several reasons:
Readability: Using exceptions makes it easier to follow the program’s logic. You can write the main path of execution in a straightforward manner without littering the code with error-checking conditionals.
Maintainability: With exceptions, you separate the error-handling code from the regular code, making it easier to update or extend functionality without risking the introduction of errors.
Rich Context: Exceptions can carry more context about the error, as they can include not just a status but also additional metadata. This can be helpful for debugging or for providing more descriptive error messages.
Stack Unwinding: When an exception is thrown, the runtime system searches back through the call stack to find the nearest enclosing exception handler. This makes it easier to handle errors at the appropriate level of abstraction.
Hybrid Approaches
Some modern languages and frameworks use a combination of both error codes and exceptions for different scenarios. For example, in asynchronous programming or when dealing with third-party libraries, error codes might be more appropriate for indicating status without disrupting the flow of execution.
Summary
While HTTP and similar protocols make effective use of error codes for cross-system communication, within your own programs, using exceptions generally leads to cleaner, more maintainable code. However, the choice between exceptions and error codes can also depend on the programming language, performance considerations, and specific use cases.
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