How to ensure that an array is valid#

This is a stub: I intend to write this article, but haven’t yet.

If you need it soon, create an issue saying so and I’ll make it a higher priority.

The text of your issue doesn’t have to be much more than a link to this page, so I can be sure which page you’re referring to. If you add details about how and why you need it, however, I may be able to tailor the text to help you more.