Remove nil value from array of hash

Question

My array of hash is like:

[
  {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!107", :name=>"Folder 11", :type=>"folder"},
  {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!105", :name=>"Pictures", :type=>"album"}, 
  {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!113", :name=>"Public", :type=>"folder"}, 
  {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!124", :name=>"sasd", :type=>"folder"}, 
  {:id=>nil, :name=>nil, :type=>nil}, 
  {:id=>nil, :name=>nil, :type=>nil},
  {:id=>nil, :name=>nil, :type=>nil},
  {:id=>nil, :name=>nil, :type=>nil}, 
  {:id=>nil, :name=>nil, :type=>nil}, 
  {:id=>nil, :name=>nil, :type=>nil}, 
  {:id=>nil, :name=>nil, :type=>nil}
]

How can I remove nil values if in my hash id is nil?

Please edit to clarify (even though you've selected an answer, as many people may read your question in future). "How can I remove nil value if my hash id is nil? doesn't make sense. You can remove values without removing keys. Perhaps you mean you want to remove all hashes h for which h[:id].nil? #=> true? If so, say so (and if your array is a, do you want to modify a or return an array equal to a with some (hash) elements removed?), Be precise in all things Ruby! — Cary Swoveland
– Cary Swoveland, Commented Jul 20, 2015 at 6:53

souslov · Accepted Answer · 2017-10-17 14:56:13Z

5

You can use reject:

arr.reject{|h| h[:id].nil?}

=> [{:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!107", :name=>"Folder 11", :type=>"folder"},
    {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!105", :name=>"Pictures", :type=>"album"},
    {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!113", :name=>"Public", :type=>"folder"},
    {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!124", :name=>"sasd", :type=>"folder"}]

Demo

Or select:

arr.select { |h| h[:id] }

Demo

edited Oct 17, 2017 at 14:56

answered Jul 20, 2015 at 6:04

souslov

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Comments

Gagan Gami · Accepted Answer · 2015-07-20 06:27:16Z

1

If your concern is to remove element which hash id is nil then better to use delete_if

array.delete_if { |h| h[:id].nil? }
 => [
      {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!107", :name=>"Folder 11", :type=>"folder"}, 
      {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!105", :name=>"Pictures", :type=>"album"},
      {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!113", :name=>"Public", :type=>"folder"}, 
      {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!124", :name=>"sasd", :type=>"folder"}
    ]

Note: reject will returns a new array containing the items in self for which the given block is not true. While delete_if will Deletes every element of self for which block evaluates to true.

edited Jul 20, 2015 at 6:27

answered Jul 20, 2015 at 6:22

Gagan Gami

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Comments

shivam · Accepted Answer · 2015-07-20 06:04:16Z

I assume you want to get all hashes whose values are not all nil. You can do that by:

arr = [{:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!107", :name=>"Folder 11", :type=>"folder"}, {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!105", :name=>"Pictures", :type=>"album"}, {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!113", :name=>"Public", :type=>"folder"}, {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!124", :name=>"sasd", :type=>"folder"}, {:id=>nil, :name=>nil, :type=>nil}, {:id=>nil, :name=>nil, :type=>nil}, {:id=>nil, :name=>nil, :type=>nil}, {:id=>nil, :name=>nil, :type=>nil}, {:id=>nil, :name=>nil, :type=>nil}, {:id=>nil, :name=>nil, :type=>nil}, {:id=>nil, :name=>nil, :type=>nil}]

arr.find_all { |h| !h.values.compact.empty? }
# => [{:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!107", :name=>"Folder 11", :type=>"folder"}, {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!105", :name=>"Pictures", :type=>"album"}, {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!113", :name=>"Public", :type=>"folder"}, {:id=>"folder.cecb8eb83d90dbeb.CECB8EB83D90DBEB!124", :name=>"sasd", :type=>"folder"}]

Travis · Accepted Answer · 2015-07-20 06:06:54Z

0

You want to use the select method to filter the array.

list = list.select { |item| item[:id] != nil }

answered Jul 20, 2015 at 6:06

Travis

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