紅寶石容易尋找鍵值對的哈希

Question

數組

假設我有此數組哈希：

[ 
{"href"=>"https://company.campfirenow.com", "name"=>"Company", "id"=>123456789, "product"=>"campfire"}, 
{"href"=>"https://basecamp.com/123456789/api/v1", "name"=>"Company", "id"=>123456789, "product"=>"bcx"}, 
{"href"=>"https://company.highrisehq.com", "name"=>"Company", "id"=>123456789, "product"=>"highrise"} 
] 

我如何解析「HREF」的哈希值，其中「產品」 =>「bcx」

有什麼簡單的方法可以在Ruby中做到這一點？

Answer 1

ary = [ 
    {"href"=>"https://company.campfirenow.com", "name"=>"Company", "id"=>123456789, "product"=>"campfire"}, 
    {"href"=>"https://basecamp.com/123456789/api/v1", "name"=>"Company", "id"=>123456789, "product"=>"bcx"}, 
    {"href"=>"https://company.highrisehq.com", "name"=>"Company", "id"=>123456789, "product"=>"highrise"} 
] 

p ary.find { |h| h['product'] == 'bcx' }['href'] 
# => "https://basecamp.com/123456789/api/v1" 

請注意，這隻適用於元素存在。否則你將被調用訂閱操作[]上nil，這將引發異常，所以你可能要檢查的是第一：

if h = ary.find { |h| h['product'] == 'bcx' } 
    p h['href'] 
else 
    puts 'Not found!' 
end 

如果需要執行該操作多次，你應該建立自己數據結構更快查找：

href_by_product = Hash[ary.map { |h| h.values_at('product', 'href') }] 
p href_by_product['campfire'] # => "https://company.campfirenow.com" 
p href_by_product['bcx']  # => "https://basecamp.com/123456789/api/v1"