[andrewbinstock]

Author here. Zero-length arrays are used in the narrow domain you mention. but they are rare in bread-and-butter Java programming. Given some of the other comments on this page, you can see that this aspect is new to multiple readers. And in my experience speaking to Java devs, the reaction of surprise is far more common than "of course, I use them."

[SeanLuke]

Thing is, practically every modern programming language has zero-length arrays or lists. This is derived from Lisp, which had zero-length arrays (and of course zero-length lists). It's not at all surprising. What ought to be surprising is that among languages developed in the last 40 years, C++ almost uniquely does not have them. I use zero-length arrays all the time in my coding, as does everyone I know. I think they're probably much more common than you imagine.