feat(last): add optional n elements parameter

[danielbayley]

For example:

const array = [1,2,3,4]

_.last(array, { n: 2 }) // [3, 4]

_.last(array) // 4

[array].map(_.last) // [4]

[Trott]

Adding this feature seems like it will break use cases where last() is used as a callback to Array.prototype.map() and similar functions.

It also seems like there's a footgun where .last([1], 500) returns 1 but .last([1,2,3], 500) returns an array.

[danielbayley]

Adding this feature seems like it will break use cases where last() is used as a callback to Array.prototype.map() and similar functions.

@Trott @blikblum See fix, and response in #5841 (comment) …

Fair point. My first contribution to this project, so not entirely sure what the design goal specifics are… But my assumption was that pure functional methods—with strict arity—were for lodash/fp?

An alternative approach might be to have something like lastN/tailN additional methods…

[jdalton]

Our last method will be dropped for Array.prototype.at as in array.at(-1):
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at

[danielbayley]

Our last method will be dropped for Array.prototype.at as in array.at(-1): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at

@jdalton That’s nice, but it doesn’t give you a range as is the point of this PR…

[jdalton]

Are you thinking of https://lodash.com/docs/4.17.15#takeRight ?