What is the For-Case Antipattern?

Today's TDWTF article starts with a confession from the author: I didn’t know what the For-Case anti-pattern was until relatively recently, when there were a spate of articles condemning it as an anti-pattern. I’m sure I’ve probably used it, at some point, but I never knew it by name. It’s thought of as a textbook antipattern that generally implies a misunderstanding of for loop, case statements, the problem being solved, or some combination of all three. He then proceeds as if the reader, naturally, knows what the For-Case anti-pattern is without any further explanation being needed. But I don't! I haven't seen the "spate of articles" that Remy talks about, and the only significant reference that I can find on Google (besides Remy's article) is a blog post by Raymond Chen about the for-if antipattern, which is apparently related. He doesn't define the "for-case anti-pattern" either, though. What is this "For-Case anti-pattern" that these guys are talking about, and what makes it an anti-pattern?

Mar 5, 2025 - 21:07

Today's TDWTF article starts with a confession from the author:

I didn’t know what the For-Case anti-pattern was until relatively recently, when there were a spate of articles condemning it as an anti-pattern. I’m sure I’ve probably used it, at some point, but I never knew it by name. It’s thought of as a textbook antipattern that generally implies a misunderstanding of for loop, case statements, the problem being solved, or some combination of all three.

He then proceeds as if the reader, naturally, knows what the For-Case anti-pattern is without any further explanation being needed.

But I don't! I haven't seen the "spate of articles" that Remy talks about, and the only significant reference that I can find on Google (besides Remy's article) is a blog post by Raymond Chen about the for-if antipattern, which is apparently related. He doesn't define the "for-case anti-pattern" either, though.

What is this "For-Case anti-pattern" that these guys are talking about, and what makes it an anti-pattern?