CODEWITHSUNDEEP
rubyarrayshashmap
Brazhnyk Yuriy
Brazhnyk Yuriy

Reputation: 417

How to "zip" two arrays into hash

I want to "zip" two arrays into a Hash.

From:

['BO','BR']
['BOLIVIA','BRAZIL']

To:

{BO: 'BOLIVIA', BR:'BRAZIL'}

How can I do it?

Upvotes: 31

Views: 14765

Answers (5)

lurker
lurker

Reputation: 58284

I would do it this way:

keys = ['BO','BR']
values = ['BOLIVIA','BRAZIL']

Hash[keys.zip(values)]
# => {"BO"=>"BOLIVIA", "BR"=>"BRAZIL"}

If you want symbols for keys, then:

Hash[keys.map(&:to_sym).zip(values)]
# => {:BO=>"BOLIVIA", :BR=>"BRAZIL"}

In Ruby 2.1.0 or higher, you could write these as:

keys.zip(values).to_h
keys.map(&:to_sym).zip(values).to_h

As of Ruby 2.5 you can use .transform_keys:

Hash[keys.zip(values)].transform_keys { |k| k.to_sym }

Upvotes: 53

kamal patwa
kamal patwa

Reputation: 479

You can make a zipped array and then convert the array into hash like so :

keys = ['BO','BR']
values = ['BOLIVIA','BRAZIL']    
array = key.zip(values) # => [['BO','BOLIVIA'],['BR','BRAZIL']]
hash = array.to_h # => {'BO' => 'BOLIVIA','BR' => 'BRAZIL'}

Upvotes: 0

Малъ Скрылевъ
Малъ Скрылевъ

Reputation: 16505

Just use the single Array of the twos, and then transpose it, and generate Hash:

keys = ['BO','BR']
values = ['BOLIVIA','BRAZIL']
Hash[[keys,values].transpose]
# => {"BO"=>"BOLIVIA", "BR"=>"BRAZIL"}

or for newer ruby version:

[keys,values].transpose.to_h

Upvotes: 7

Jörg W Mittag
Jörg W Mittag

Reputation: 369536

Ironically, if you just sprinkle some dots and underscores into your question, it just works:

I want to "zip" two arrays into_hash

ary1.zip(ary2).to_h
# => { 'BO' => 'BOLIVIA', 'BR' => 'BRAZIL' }

Actually, you specified in your output hash that the keys should be Symbols not Strings, so we need to convert them first:

ary1.map(&:to_sym).zip(ary2).to_h
# => { BO: 'BOLIVIA', BR: 'BRAZIL' }

Upvotes: 6

samuil
samuil

Reputation: 5081

Quite readable version would be:

keys = ['BO','BR']
values = ['BOLIVIA','BRAZIL']

keys.zip(values).each_with_object({}) do |(key, value), hash|
  hash[key.to_sym] = value
end

Upvotes: 3

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