From: Adam Prescott <adam@...>
Date: 2013-02-10T12:20:29+09:00
Subject: Re: elegant way to determine if something is defined

> Object.defined?('a')

defined?(a) #=> nil
b = a + 1 #=> NameError
a = 1
defined?(a) #=> "local-variable" (strings are truthy)

However, relying on defined?(a) to check for local variables is
probably a code smell: they're local variables, why isn't the code
just written properly? What's the problem you're trying to solve?