Which guideline is flagged when an API returns null instead of an empty collection?

Which guideline is flagged when an API returns null instead of an empty collection?

• A. G9 Avoid overly clever APIs
• B. G21 Fail fast; don't fail silently
• C. G11 Pay attention to edge cases
• D. G13 Design/document for inheritance or prohibit it

Answer: (C)

When an API returns null instead of an empty collection, it can lead to confusion for developers who consume the API. An empty collection clearly represents the concept of "no items" and allows the client to iterate over it safely without additional null checks. By adhering to the principle of paying attention to edge cases, the API design can handle scenarios where no data is available more intuitively. This practice enables clients to write cleaner, less error-prone code, as they can treat the API responses in a consistent manner, specifically by differentiating between the absence of data (empty collection) and an unexpected state (null). Recognizing these edge cases ensures a more predictable and user-friendly API experience.

When an API returns null instead of an empty collection, it can lead to confusion for developers who consume the API. An empty collection clearly represents the concept of "no items" and allows the client to iterate over it safely without additional null checks. By adhering to the principle of paying attention to edge cases, the API design can handle scenarios where no data is available more intuitively. This practice enables clients to write cleaner, less error-prone code, as they can treat the API responses in a consistent manner, specifically by differentiating between the absence of data (empty collection) and an unexpected state (null). Recognizing these edge cases ensures a more predictable and user-friendly API experience.