Ruby - protected 方法

Question

我有以下 Ruby 程序:

class Access

def retrieve_public
puts "This is me when public..."
end

private
def retrieve_private
puts "This is me when privtae..."
end

protected
def retrieve_protected
puts "This is me when protected..."
end

end


access = Access.new
access.retrieve_protected

当我运行它时，我得到以下信息:

accessor.rb:23: protected method `retrieve_protected' called for #<Access:0x3925
758> (NoMethodError)

这是为什么？

谢谢。

Answer 1

因为您只能从该对象或该类(或子类)的另一个对象的内实例方法直接调用 protected 方法

class Access

  def retrieve_public
    puts "This is me when public..."
    retrieve_protected

    anotherAccess = Access.new
    anotherAccess.retrieve_protected 
  end

end

#testing it

a = Access.new

a.retrieve_public

# Output:
#
# This is me when public...
# This is me when protected...
# This is me when protected...