ruby - 带哈希的数组，如何合并相同的键并添加其值

Question

我有一个包含哈希值的数组。如果它们具有相同的 key ，我只想添加其值。

@receivers << result

@receivers
=> [{:email=>"<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="70050315022f404230091f021c1f1f1b5e131f1d" rel="noreferrer noopener nofollow">[email protected]</a>", :amount=>10.00}]
result
=> {:email=>"<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="34414751466b0406744d5b46585b5b5f1a575b59" rel="noreferrer noopener nofollow">[email protected]</a>", :amount=>7.00}

我希望上面的结果看起来像这样

[{:email=>"<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d1a4a2b4a38ee1e391a8bea3bdbebebaffb2bebc" rel="noreferrer noopener nofollow">[email protected]</a>", :amount=>17.00}]

有人知道如何做到这一点吗？

这是整个方法

  def receivers
    @receivers = []
    orders.each do |order|
      product_email = order.product.user.paypal_email
      outfit_email  = order.outfit_user.paypal_email
      if order.user_owns_outfit?
        result = { email: product_email, amount: amount(order.total_price) }
      else
        result = { email: product_email, amount: amount(order.total_price, 0.9),
                   email: outfit_email,  amount: amount(order.total_price, 0.1) }
      end
      @receivers << result
    end
  end

Answer 1

使用Enumerable#group_by

@receivers.group_by {|h| h[:email]}.map do |k, v|
  {email: k, amount: v.inject(0){|s,h| s + h[:amount] } }
end
# => [{:email=>"<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="8ffafceafdd0bfbdcff6e0fde3e0e0e4a1ece0e2" rel="noreferrer noopener nofollow">[email protected]</a>", :amount=>17.0}]

使用Enumerable#each_with_object

@receivers.each_with_object(Hash.new(0)) {|h, nh| nh[h[:email]]+= h[:amount] }.map do |k, v|
 {email: k, amount: v}
end