ruby - 将实例变量实例化为块

我有下列课程

class Increasable

  def initializer(start, &increaser)
    @value = start
    @increaser = increaser
  end

  def increase()
    value = increaser.call(value)
  end
end

如何用块初始化？做

inc = Increasable.new(1, { |val|  2 + val})

我得到

(irb):20: syntax error, unexpected '}', expecting end-of-input
inc = Increasable.new(1, { |val|  2 + val})

最佳答案

您的方法调用语法不正确。

class Increasable
  attr_reader :value, :increaser

  def initialize(start, &increaser)
    @value = start
    @increaser = increaser
  end

  def increase
    @value = increaser.call(value)
  end
end

Increasable.new(1) { |val|  2 + val }.increase # => 3

阅读Best explanation of Ruby blocks?了解块在Ruby中是如何工作的。

关于ruby - 将实例变量实例化为块，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/28703425/