Selecting items from a Ruby Hash

Question

I have a hash in Ruby that looks like this:

{"NameValues"=>[
    {"Name"=>"Field 1", "Values"=>["Data 1"]}, 
    {"Name"=>"Field 2", "Values"=>["Data 2"]}, 
    {"Name"=>"Field 3", "Values"=>["Data 3"]}, 
    {"Name"=>"Field 4", "Values"=>["Data 4"]}, 
    {"Name"=>"Field 5", "Values"=>["Data 5"]}
]}

I want to select the contents of the "Values" element by using the name from the "Names" element, eg, locate the "Data 3" string by searching for "Field 3" etc.

Answer 1

You could use the Enumerable#find method to find the hash by name:

hash = {"NameValues"=>[
    {"Name"=>"Field 1", "Values"=>["Data 1"]}, 
    {"Name"=>"Field 2", "Values"=>["Data 2"]}, 
    {"Name"=>"Field 3", "Values"=>["Data 3"]}, 
    {"Name"=>"Field 4", "Values"=>["Data 4"]}, 
    {"Name"=>"Field 5", "Values"=>["Data 5"]}
]}

p hash['NameValues'].find{ |h| h['Name'] == 'Field 3'}['Values']
#=> ["Data 3"]

find basically iterates through the NameValues array until a matching element is found. You can then get the Values from the returned element.