Issues iterating over deeply nested hash of hashes inside an array

Question

So, a quick mockup of my issue can look like this ...

`def problem
  [{
     'Hash1' => {
       'Hash_1' => 'abcd',
       'Hash_2' => 'abcd',
       'Hash_3' => nil,
     }
   },
   {
     'Hash2' => {
       'Hash_1' => 'efg',
       'Hash_2' => 'efg',
       'Hash_3' => 'efg'
     }
   },
   {
     'Hash3' => {
       'Hash_1' => 'hijk',
       'Hash_2' => nil,
       'Hash_3' => 'hijk'
     }
   }]
end`

For example, I want to use a .each method to find the value of Hash2 for every instance of it, in all of the 3 hashes.

When I do this I get returned with Nil values everywhere. As an added issue, if hash2 has a nil value, I want to return N/A instead of having nil.

   problem.each do |item|
    item.each do |thing|
      thing.each do |other_thing|
        puts other_thing['Hash1']
      end
    end
   end

Which returns the following:

Hash1
abcd

efg

hijk

The spaces being nil values. I am super stumped. Anyone wanna take a crack at this?

if you need a function to work for a specific set of nesting post the data you need to work with. the answer posted works just fine for the example data — TheRealMrCrowley, Feb 05 '17 at 04:01

TheRealMrCrowley · Accepted Answer · 2017-02-05T03:41:16.283

1

you are putsing undefined variables without any conditional checking

using the above data as an example:

problem.each do |arr_item|
  arr_item.each do |hash_key, hash|
    if hash['Hash_2']
      puts hash['Hash_2']
    else
      puts 'N/A'
    end
  end
end

edited Feb 05 '17 at 03:41

answered Feb 05 '17 at 03:23

TheRealMrCrowley

976
7
24

@MikeAdamski updated, forgot the object syntax for hashes for a minute – TheRealMrCrowley Feb 05 '17 at 03:41
@MikeAdamski please mark the answer if it solves your issue – TheRealMrCrowley Feb 05 '17 at 03:47
Still wont work, returns "N/A" for every `key`. I am still trying to play around with the syntax but not getting anywhere, I'll come back and update if I get it, thanks! – vin_Bin87 Feb 05 '17 at 03:58
then the data you posted is not the same as what you are working with – TheRealMrCrowley Feb 05 '17 at 03:59
the code above works perfectly for your example data – TheRealMrCrowley Feb 05 '17 at 04:00

score 0 · Answer 2 · answered Feb 05 '17 at 05:00

arr = [{ 'Hash1'=>{ 'Hash_1'=>'abcd', 'Hash_2'=>'abcd', 'Hash_3'=>nil    } },
       { 'Hash2'=>{ 'Hash_1'=>'efg',  'Hash_2'=>'efg',  'Hash_3'=>'efg'  } },
       { 'Hash3'=>{ 'Hash_1'=>'hijk', 'Hash_2'=>nil,    'Hash_3'=>'hijk' } }
      ]

arr.map { |h| h.first.last["Hash_2"] || 'N/A' }
  #=> ["abcd", "efg", "N/A"]

Issues iterating over deeply nested hash of hashes inside an array

2 Answers2