Brian Weinreich
Brian Weinreich

Reputation: 7702

Ruby easy search for key-value pair in an array of hashes

Suppose I have this array of hashes:

[
{"href"=>"https://company.campfirenow.com", "name"=>"Company", "id"=>123456789, "product"=>"campfire"},
{"href"=>"https://basecamp.com/123456789/api/v1", "name"=>"Company", "id"=>123456789, "product"=>"bcx"}, 
{"href"=>"https://company.highrisehq.com", "name"=>"Company", "id"=>123456789, "product"=>"highrise"}
]

How can I parse the "href" value of the hash where "product"=>"bcx"

Is there any easy way to do this in Ruby?

Upvotes: 27

Views: 34983

Answers (1)

Niklas B.
Niklas B.

Reputation: 95308

ary = [
  {"href"=>"https://company.campfirenow.com", "name"=>"Company", "id"=>123456789, "product"=>"campfire"},
  {"href"=>"https://basecamp.com/123456789/api/v1", "name"=>"Company", "id"=>123456789, "product"=>"bcx"}, 
  {"href"=>"https://company.highrisehq.com", "name"=>"Company", "id"=>123456789, "product"=>"highrise"}
]

p ary.find { |h| h['product'] == 'bcx' }['href']
# => "https://basecamp.com/123456789/api/v1"

Note that this only works if the element exists. Otherwise you will be calling the subscription operator [] on nil, which will raise an exception, so you might want to check for that first:

if h = ary.find { |h| h['product'] == 'bcx' }
  p h['href']
else
  puts 'Not found!'
end

If you need to perform that operation multiple times, you should build yourself a data structure for faster lookup:

href_by_product = Hash[ary.map { |h| h.values_at('product', 'href') }]
p href_by_product['campfire'] # => "https://company.campfirenow.com"
p href_by_product['bcx']      # => "https://basecamp.com/123456789/api/v1"

Upvotes: 55

Related Questions