如何检查特定的键值对是否存在于Rails中的ruby中的json数组中

Question

I have an array of hashes as json , so how to check my array of hashes contains a hash with a given key-value pair.

This is my json

[{"question"=>"0a2a3452", "answer"=>"bull"}, {"question"=>"58deacf9", "answer"=>"bullafolo"}, {"question"=>"32c53e5f", "answer"=>"curosit"}, {"question"=>"b5546bcf", "answer"=>""}, {"question"=>"0f0b314", "answer"=>""}]

I tried looping through the json array, but this is tedious, as I need to check that if that json has that hash with a given key-value pair

It's a questionnaire form, in which I have to perform an update on answers

 if !@client_find.nil?    
     @client_find.questionnaire
     params[:commit].each do |key, value|
       @json=[]
       @json = @client_find.questionnaire
      if !value.empty? && @json.include?(key)
        puts "blunderc "+ value.inspect
        @new_append = Hash.new
        @new_append[:question] = key
        @new_append[:answer]= value
        @json << @new_append
      end

       if !key.empty? && !value.empty?
         #logic
         @json.each  do |u|
           if (u.key? key)
             puts "bothu "+ u[key].inspect
             u[key] = value
           end
         end
       end
    end

Answer 1

Array#any? iterates through the array. In each iteration I check wether the current hash has the searched question key or not. If a hash is found Array#any? returns true otherwise false.

array = [{"question"=>"0a2a3452", "answer"=>"bull"}, {"question"=>"58deacf9", "answer"=>"bullafolo"}, {"question"=>"32c53e5f", "answer"=>"curosit"}, {"question"=>"b5546bcf", "answer"=>""}, {"question"=>"0f0b314", "answer"=>""}]

search_for_key = '0a2a3452'

array.any?{|hash| hash['question'] == search_for_key}

Answer 2

I'll assume that you want to check the existence of a hash which has the key/value pair "quesetion" => "some-value" .

Here's how you can do it:

array.any? { |item| item['question'] == 'some-question-id' }

Answer 3

考虑到您正在检查特定键是否存在

@json.any? {|obj| obj.key?(your_particular_key)

Answer 4

You can filter the array using Enumerable#select to get only the hashes that contains the desired key.

filtered = my_hash.select { |item| item['desired_key'] }

That's possible because nil is falsey. If you input is a raw JSON you'll need to parse it to a Ruby hash using JSON#parse or any other equivalent method.

filtered will give you all the hashes that contain the desired_key .

Answer 5

Is that what you want ? Btw guitarman's answer is way better !

questions = [{"question"=>"0a2a3452", "answer"=>"bull"}, {"question"=>"58deacf9", "answer"=>"bullafolo"}, {"question"=>"32c53e5f", "answer"=>"curosit"}, {"question"=>"b5546bcf", "answer"=>""}, {"question"=>"0f0b314", "answer"=>""}]

result = questions.find { |question| question['question'] == "Bonour" }

if result.nil?
    puts "Not found"
else
    puts "#{result['question']} #{result['answer']}"
end