标签：object key erro any 2.4 extra blog end idt
dig(key, ...) → objectclick to toggle source
Extracts the nested value specified by the sequence of idx objects by calling dig at each step, returning nil if any intermediate step is nil.
http://ruby-doc.org/core-2.4.0/Hash.html#method-i-dig
h = { foo: {bar: {baz: 1}}}
h.dig(:foo, :bar, :baz) #=> 1
h.dig(:foo, :zot, :xyz) #=> nil
g = { foo: [10, 11, 12] }
g.dig(:foo, 1) #=> 11
g.dig(:foo, 1, 0) #=> TypeError: Integer does not have #dig method
g.dig(:foo, :bar) #=> TypeError: no implicit conversion of Symbol into Integer
举例子：
if item["ui_type"]["pos"].present? display_item.x_axis = item["ui_type"]["pos"]["x"] if item["ui_type"]["pos"]["x"].present? display_item.y_axis = item["ui_type"]["pos"]["y"] if item["ui_type"]["pos"]["y"].present? display_item.width = item["ui_type"]["pos"]["w"] if item["ui_type"]["pos"]["w"].present? display_item.height = item["ui_type"]["pos"]["h"] if item["ui_type"]["pos"]["h"].present? end
改为
display_item.x_axis = item["ui_type"]["pos"]["x"] if item.dig("ui_type", "pos", "x").present? display_item.y_axis = item["ui_type"]["pos"]["y"] if item.dig("ui_type", "pos", "y").present? display_item.width = item["ui_type"]["pos"]["w"] if item.dig("ui_type", "pos", "w").present? display_item.height = item["ui_type"]["pos"]["h"] if item.dig("ui_type", "pos", "h").present?
标签：object key erro any 2.4 extra blog end idt
原文地址：http://www.cnblogs.com/iwangzheng/p/6339733.html
