Rails用Struct代替Hash

#有时候经常要自定义一些hash列表。

hash = {:matched=>[{:lidx=>"lidx1",:cont=>"cont1"},{:lidx=>"lidx2",:cont=>"cont2"}]}
hash[:matched].each do |ma|
  p ma[:lidx]
  p ma[:cont]
end 

＃用Struct代替Hash

GrepMatchedItem = Struct.new(:lidx, :cont)
matched = []
matched << GrepMatchedItem.new(lidx, line)

matched.each do |m|
  p m.lidx
  p m.cont
end

#Struct的好处还可以像类一样给他定义一些方法

Customer = Struct.new(:name, :address) do
  def greeting
    "Hello #{name}!"
  end
end
Customer.new("Dave", "123 Main").greeting  # => "Hello Dave!"