It is not nonsense. You use that expression if you want to check if a variable exists or not (as opposed to being set to an empty string) which is an extremely common problem.
That what I meant by "I can see what they were trying to do". It's would have been correct if the "+x" was inside the braces, even in context. He did in fact want to check if the variable was unset and error out, and that's what hurts so much.
There was a real and correct analysis that, hey, I want to make sure the variable is set here. Only to then drop it because you get told the syntax is wrong. The response I'm looking for when I say "This syntax won't do what you're looking to do" would be something like "what am I trying to do? and why wont this do it?" not "well it's just some AI code, I'll just remove it".
It is not nonsense. You use that expression if you want to check if a variable exists or not (as opposed to being set to an empty string) which is an extremely common problem.