Filter JSON array by value with Ruby
require 'json'
arr = JSON.parse <<END_OF_JSON
[
{"name":"Idaho","state":{"id":1,"name":"A"}},
{"name":"Wyoming","state":{"id":1,"name":"A"}},
{"name":"Montana","state":{"id":2,"name":"B"}},
{"name":"South Dakota","state":{"id":1,"name":"B"}}
]
END_OF_JSON
results = []
arr.each do |hash|
results << hash["name"] if hash["state"]["name"] == "A"
end
p results
--output:--
["Idaho", "Wyoming"]
require 'json'
json = <<'JSON_STRING'
[
{"name":"Idaho","state":{"id":1,"name":"A"}},
{"name":"Wyoming","state":{"id":1,"name":"A"}},
{"name":"Montana","state":{"id":2,"name":"B"}},
{"name":"South Dakota","state":{"id":1,"name":"B"}}
]
JSON_STRING
data = JSON.parse json
data.map(&:values).select { |state, values| values["name"] == ?A }
#=> [["Idaho", {"id"=>1, "name"=>"A"}], ["Wyoming", {"id"=>1, "name"=>"A"}]]
data.map(&:values).select { |state, values| values["name"] == ?A }.map(&:first)
#=> ["Idaho", "Wyoming"]