Ruby new unique array of nested array items

Question

Looking for a way to reduce a nested list of arrays, into a single array of items that are unique, and drop any empty arrays.

Looking to reduce this array:

[[2700, 177, 2092, 176, 188], [123, 1234], []]

Down to this new array:

[2700, 177, 2092, 176, 188, 123, 1234]

Have tried array.uniq.compact, but did not work.

Thanks for any suggestions.

fbonetti · Accepted Answer · 2014-07-14 14:54:57Z

10

You need to flatten the array first.

array.flatten.uniq

A few notes:

Array#flatten merges all child arrays into the top level array. Since empty arrays do not contain any elements, they will automatically be removed.
Array#compact returns a new array with the nil elements removed.
Array#uniq returns a new array with only unique elements.

answered Jul 14, 2014 at 14:48

fbonetti

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Comments

Roman Kiselenko · Accepted Answer · 2014-07-14 14:48:33Z

2

Returns a new array that is a one-dimensional flattening of self (recursively).

=> [[2700, 177, 2092, 176, 188], [123, 1234], []].flatten
#> [2700, 177, 2092, 176, 188, 123, 1234]

answered Jul 14, 2014 at 14:48

Roman Kiselenko

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