Accessing variables using overloading brackets [] in Ruby
Hi i want to do the following. I simply want to overload the [] method in order to access the instance variables... I know, it doesn't make great sense at all, but i want to do this for some strange reason :P
It will be something 开发者_StackOverflowlike this...
class Wata
attr_accessor :nombre, :edad
def initialize(n,e)
@nombre = n
@edad = e
end
def [](iv)
self.iv
end
end
juan = Wata.new('juan',123)
puts juan['nombre']
But this throw the following error:
overload.rb:11:in `[]': undefined method 'iv' for # (NoMethodError)
How can i do that?
EDIT
I have found also this solution:
def [](iv)
eval("self."+iv)
end
Variables and messages live in a different namespace. In order to send the variable as a message, you'd need to define it as either:
def [](iv)
send iv
end
(if you want to get it through an accessor)
or
def [](iv)
instance_variable_get "@#{iv}"
end
(if you want to access the ivar directly)
try instance_variable_get
instead:
def [](iv)
instance_variable_get("@#{iv}")
end
精彩评论