[Groxx]

and god help you if those loops are pairing People and Products.

though now that I write that out... it would be really nice if you could optionally type iteration vars so they couldn't be used on other collections / as plain integers. I haven't seen any languages that do that though, aside from it being difficult to do by accident in proof-oriented languages.

[jayd16]

You usually don't need an index that can't be used elsewhere. If you don't then you can abstract it away entirely and use an iterator or foreach features.

[Groxx]

Depends on the language. Doing that is a huge pain in Go (until fairly recently, and it's still quite abnormal or closure-heavy), so the vast majority of code there does manual index-pairing instead of e.g. a zip iterator when going through two paired arrays.