Question

我有以下内容：

@products = {
  2 => [
    #<Review id: 9, answer01: 3, score: 67, style_id: 2, consumer_id: 2,
    branch_id: 2, business_id: 2>
  ],
  15 => [
    #<Review id: 10, answer01: 3, score: 67, style_id: 2, consumer_id: 2,
    branch_id: 2, business_id: 2>,
    #<Review id: 11, answer01: 3, score: 67, style_id: 2, consumer_id: 2,
    branch_id: 2, business_id: 2>
  ]
}

我想平均与每个产品的哈希键相关的所有评论的分数。我怎么能这样做？

Answer 1

迭代哈希：

hash = {}
hash.each_pair do |key,value|
  #code
end

迭代数组：

arr=[]
arr.each do |x|
  #code
end

所以迭代数组的哈希（假设我们在哈希中的每个点上迭代每个数组）将这样做：

hash = {}
hash.each_pair do |key,val|
  hash[key].each do |x|
    #your code, for example adding into count and total inside program scope
  end
end

Answer 2

是的，只需使用map为每个产品制作得分和数组，然后取出数组的平均值。

average_scores = {}
@products.each_pair do |key, product|
  scores = product.map{ |p| p.score }
  sum = scores.inject(:+) # If you are using rails, you can also use scores.sum
  average = sum.to_f / scores.size
  average_scores[key] = average
end

Answer 3

感谢Shingetsu的回答，我一定会赞成它。我不小心弄清了自己的答案。

trimmed_hash = @products.sort.map{|k, v| [k, v.map{|a| a.score}]}
trimmed_hash.map{|k, v| [k, v.inject(:+).to_f/v.length]}

迭代数组的哈希值

3 个答案: