Ruby:定义实例变量的更短方式

Question

我正在寻找在 initialize 方法中定义实例变量的更短方式:

class MyClass
  attr_accessor :foo, :bar, :baz, :qux
  # Typing same stuff all the time is boring
  def initialize(foo, bar, baz, qux)
    @foo, @bar, @baz, @qux = foo, bar, baz, qux
  end
end

Ruby 是否有任何内置功能可以避免这种猴子工作？

# e. g.
class MyClass
  attr_accessor :foo, :bar, :baz, :qux
  # Typing same stuff all the time is boring
  def initialize(foo, bar, baz, qux)
    # Leveraging built-in language feature
    # instance variables are defined automatically
  end
end

Answer 1

见面Struct ，专为此而生的工具!

MyClass = Struct.new(:foo, :bar, :baz, :qux) do
  # Define your other methods here. 
  # Initializer/accessors will be generated for you.
end

mc = MyClass.new(1)
mc.foo # => 1
mc.bar # => nil

我经常看到人们这样使用 Struct:

class MyStruct < Struct.new(:foo, :bar, :baz, :qux)
end

但这会导致多出一个未使用的类对象。为什么在不需要时制造垃圾？