Merge array's consecutive items when equal

Question

Trying to create an array out of existing one where all the consecutive items are merged:

[undefined, undefined, undefined] -> [undefined]

[undefined, 'item', undefined] -> [undefined, 'item', undefined]

[undefined, undefined, 'item'] -> [undefined, 'item']

I've tried [...new Set(temp)], where temp is the one of the above but that does not keep indexes.

EDIT: It would be beneficial if I could know number of items being merged into one when applicable

Please note the 2nd case where, despite duplicated items, array stays untouched

It's not a duplicate as this is about duplicate _consecutive_ items. — Zlatko, Oct 07 '19 at 09:35

score 2 · Answer 1 · answered Oct 07 '19 at 09:37

2

  array.filter((el, i, a) => !i || el !== a[i - 1])

answered Oct 07 '19 at 09:37

Jonas Wilms

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Okay, this may work, but considering the single-letter variable names and the fact that the OP didn't think of this approach, could you explain what's going on here? – Cerbrus Oct 07 '19 at 09:44

Merge array's consecutive items when equal

1 Answers1