How check in ruby if nested array is empty?

Question

Response list returns empty nested array: [[], [], []]

How better test with ruby that following nested array is empty?

How do you define an "empty nested array"? The one you have in your question is most definitely not empty, it contains three elements. — Jörg W Mittag
– Jörg W Mittag, Commented Oct 5, 2022 at 21:12

mechnicov · Accepted Answer · 2022-10-05 10:28:10Z

4

To check all nested arrays are empty with Array#all?

[[], [], []].all?(&:empty?)
# => true

[[1], [2], []].all?(&:empty?)
# => false

[[1], [2], [3]].all?(&:empty?)
# => false

To check at least one nested is empty with Array#any?

[[], [], []].any?(&:empty?)
# => true

[[1], [2], []].any?(&:empty?)
# => true

[[1], [2], [3]].any?(&:empty?)
# => false

answered Oct 5, 2022 at 10:28

mechnicov

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Comments

Simon · Accepted Answer · 2022-10-05 10:33:09Z

3

If you want to handle deeply nested arrays, you probably want to flatten your array first:

[[], [], []].flatten.empty?
=> true

[[], [[], [[]]]].flatten.empty?
=> true

[[], [[], [[1]]]].flatten.empty?
=> false

answered Oct 5, 2022 at 10:33

Simon

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