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There's nothing wrong with Array#map passing callback(val, i, array), it's a legitimate feature, and the two other arguments can be omitted in actual callbacks.

There's nothing wrong with Array#map passing callback(val, i, array), it's a legitimate feature, and the two other arguments can be omitted in actual callbacks. It just means we need to be aware of how it works, which is basically true about any programming language, any standard library, and basically any kind of tool that any kind of professional uses, whether abstract or literal: know how to use your own tools, and avoid blaming the wrench because it's a poor excuse for a hammer.

acdha 7y ago
> know how to use your own tools, and avoid blaming the wrench because it's a poor excuse for a hammer This is, of course, why famously machine shops simply put up signs saying “don't touch the whirring metal” rather than using safety guards and similar measures. I don't disagree that it's useful to have the extra arguments for map but the part which is really deadly is ignoring extra arguments, even if it's obvious why backwards-compatibility made changing it unlikely. I really wish that JavaScript had implemented keyword-arguments when the benefits had become obvious because when features like map were added a decade or two later they could have been defined as passing arguments by keyword and causing an error when given a function which didn't accept those names.