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Comment by frostik | Hacker News Reader

There's a huge gotcha: _.map, _.forech, ... can iterate over objects (often used as associative arrays) - Native map can't.

At some point you'll need lodash and co again - at least for convinience.

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Yup, this is my biggest issue with JavaScript's built-in functional utilities. It just totally ignores treating objects like dictionaries/maps. Even ES6 Maps/Sets lack functional features.

There's a strawman proposal out there to solve this but until then I'll be sticking with Lodash: https://github.com/leebyron/ecmascript-iterator-hof

We already have Object.keys()[1], and Object.values()[2] and Object.entries()[3] are in the stage 4 proposal[4] and should be safe to polyfill.

[1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

[2]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

[3]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

[4]: https://github.com/tc39/proposal-object-values-entries

Object.keys() is rather well supported these days though.

Yes, but means that you need to implement map, foreach, filter yourself. So you might be better off with lodash.

I think he's referring to `Object.keys(object).reduce`. We polyfill `Object.entries` so we do `Object.entries(object).reduce((result, [key, value]) => ...)`

for (var key of Object.keys(imps)) { }

I figured that would work with babel-2015 and it did work on Chrome and Safari but on Firefox visitors were getting:

Symbol.Iterator undefined

You need http://babeljs.io/docs/plugins/transform-es2015-for-of/ as well.

So there is much less risk in using _.each(imps, (value, key) => and not having to discover what you don't know.

I also added Firefox to the unit tests after that.

And Object.values is supported in Chrome and Firefox, and has polyfills for other browsers.

I think this is what makes Lodash so convenient, I just want expected functions like _.forEach to work with whatever I throw at it.

Lodash is helping with JavaScript language additions like

https://github.com/leobalter/object-enumerables

https://github.com/bterlson/proposal-flatMap

Furthermore, lodash/underscore contain some null object patterns: null.map(...) will throw an error, while _.map(null, ...) returns []

I agree, this is the sole reason I use atleast underscore in every project.

the repo already points that out.

>Important: Note that the native equivalents are array methods, and will not work with objects. If this functionality is needed, then Lodash/Underscore is the better option.

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