ruby - Ruby 的 send 和 public_send 方法有什么区别？

Question

我很好奇send和public_send有什么区别。例如:

class Klass
  def hello(*args)
    "Hello " + args.join(' ')
  end
end

k = Klass.new
k.send :hello, "gentle", "readers" #=> "Hello gentle readers"
k.public_send :hello, "gentle", "readers" #=> "Hello gentle readers"

Answer 1

Unlike send, public_send calls public methods only.

Source

例子:

class Klass
  private
  def private_method
    puts "Hello"
  end
end

k = Klass.new
k.send(:private_method)
# => "Hello"

k.public_send(:private_method)
# => `public_send': private method `private_method' called for #<Klass:0x007f5fd7159a80> (NoMethodError)

您可能希望使用 #public_send 而不是 #send，以免规避私有(private)/ protected 可见性。