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Ruby create an array of hashes

I've got a variable I'd like to use as a key to a hash that contains its own key and array.

e.g.

custArray = Array.new
custArray << "c1001" => "purchases" => ["prod01"]


I want to be able to do something like:

if custArray[:c1001].exists?
custArray[:c1001["purchases"] << "prod02"]
end


but I'm just totally stuck.

cust_array

custArray

5 Answers
5

You can resolve it with:

if c = custArray.find
c.dig('c1001', 'purchases') << "prod2"
end


Or if you can have more than one result with this key:

custArray.select .each do |c|
c.dig('c1001', 'purchases') << "prod2"
end


If you only want to update the first instance of the array you can do:

target = custArray.find hash
target['c1001']['purchases'] << 'prod02' if target


If you want to update all instances of the array you can do (backslashes are for console purposes only):

custArray
.select hash
.each hash


You can use select from the array of hashes to see if the key is there:

target = custArray.find
target['c1001']['purchases'] << "prod02" unless target.nil?


Or if array contains multiple hashes with the same key:

custArray.select .each do |h|
h['c1001']['purchases'] << "prod02"
end


cust_array

custArray

Also, you can write something similar to code that you already provide

custArray.each do |h|
h['c1001']['purchases'] << 'prod02' if h.keys.include?('c1001')
end


That allows reducing the count of iteration loops

c1001

custArray.find h&.dig('c1001', 'purchases')&.push("prod02")
#=> ["prod01", "prod02"]
custArray
#=> ["c1001"=>"purchases"=>["prod01", "prod02"]]

custArray.find h.key?('c1002') &.dig('c1002', 'purchases')&.push("prod02")
#=> nil
custArray
#=> ["c1001"=>"purchases"=>["prod01"]]

custArray.find h&.dig('c1001', 'popsicles')&.push("prod02")
#=> nil
custArray
#=> ["c1001"=>"purchases"=>["prod01"]]


& is Ruby's Safe Navigation Operator. See also Hash#dig. Both made their debut in Ruby v2.3.

&

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