How to check if a constant is defined by its symbol in Ruby?

Question

const = :FOO
FOO = :ok
defined? FOO => 'constant'

How to check if FOO is defined using const?

defined? eval( const.to_s )

does not work.

Answer 1

Use const_defined? instead: http://ruby-doc.org/core/classes/Module.html#M000487

Object.const_defined?(const.to_s)