Is there an inverse of _.groupBy?

Question

I am using lodash and have grouped an array of objects on a key that they shared; I then do calculations to these objects in these groups but now I need to ungroup.

Is there any way to do this in lodash?

Thanks

Answer 1

You can use _.flatMap() to "ungroup", but it won't restore the original order:

const arr = [2, 3, 4, 2, 3, 4]

const grouped = _.groupBy(arr)

console.log(JSON.stringify(grouped))

const ungrouped = _.flatMap(grouped)

console.log(JSON.stringify(ungrouped))

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