Which of the following are reasons to test an interface?

Testing an interface is crucial for several reasons, and ensuring that the interface functions as a standalone object is indeed a key reason. When an interface is designed, it often serves as a separate component that should work correctly independently before it integrates with other parts of an application. This functionality is essential to validate that it operates as intended, which includes its logic, user interactions, and data manipulations. By testing it in isolation, developers can identify issues that need to be resolved before it is combined with other application elements.

This standalone testing ensures not only that the interface behaves correctly but also that it is resilient to potential changes or issues that may arise when it interacts with other components later on. It helps in maintaining the integrity and reliability of the overall application, thus providing a solid foundation before proceeding with more complex integrations.

Other reasons listed, while important, do not capture the essence of what makes testing an interface as a standalone object critical for developers. These aspects fall under broader categories of user feedback, issue resolution, and data type validation—each valuable in its own right but not specifically about the core functionality of the interface itself.