带有数组标准的ruby切片

Question

如何为数组中的ruby创建一个切片，如下所示：

info         = { :key1 => "Lorem", :key2 => "something...", :key3 => "Ipsum" }
needed_keys  = [:key1, :key3]
info         = info.slice( needed_keys )

我想收到：

{ :key1 => "Lorem", :key3 => "Ipsum" }

Answer 1

ActiveSupport的Hash#slice不会将一组键作为参数，您必须将要提取的键作为单个参数传递，例如通过splatting needed_keys数组：

info.slice(:key1, :key3)
# => {:key1=>"Lorem", :key3=>"Ipsum"}

info.slice(*needed_keys)
# => {:key1=>"Lorem", :key3=>"Ipsum"}

Answer 2

info.select{|k,_| needed_keys.include? k }

Answer 3

您需要展开数组：

info.slice(*needed_keys)