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> Reduce also forces you to conjure up a "zero" value of the relevant type, which isn't usually difficult but it does constitute some extra mental overhead.

It's always worthwhile to consider what the result will be when you pass in an empty list.

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Right. It's just one more thing you have to think about with Reduce that's not something you have to consider with Map/Filter.

If you have need of a reducing operation though, you will still need to think about that value. If you are summing up a list of numbers, it doesn't matter whether you use reduce or a loop, you need to set some initial value.

I agree, although most of the time you do end up needing to consider it with Map/Filter. It's just, it doesn't force you to. Which means either you think about it later, or it bites you in the ass because you didn't consider the empty case. Not always—and for those cases where you don't end up needing the empty case, Reduce is probably not necessary, and Map/Filter is sufficient.

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