ruby – 将哈希传递给接受关键字参数的函数

我有像这样的哈希= {“band”=> “for King& Country”,“song_name”=> “物质”}和一个类：

class Song
  def initialize(*args,**kwargs)
    #accept either just args or just kwargs
    #initialize @band,@song_name
  end
end

我希望将散列作为关键字参数传递,如Song.new band：“for King& Country”,song_name：“Matter”是否可能？

解决方法

您必须将哈希中的键转换为符号：

class Song
  def initialize(*args,**kwargs)
    puts "args = #{args.inspect}"
    puts "kwargs = #{kwargs.inspect}"
  end
end

hash = {"band" => "for King & Country","song_name" => "Matter"}

Song.new(hash)
# Output:
# args = [{"band"=>"for King & Country","song_name"=>"Matter"}]
# kwargs = {}

symbolic_hash = hash.map { |k,v| [k.to_sym,v] }.to_h
#=> {:band=>"for King & Country",:song_name=>"Matter"}

Song.new(symbolic_hash)
# Output:
# args = []
# kwargs = {:band=>"for King & Country",:song_name=>"Matter"}

在Rails / Active Support中有Hash#symbolize_keys