Question

I would like to define a method using string elements in an array, eg:

ARRAY = ["name1", "name2"]
ARRAY.each do |k|
  def k?
    self.attribute == k
    #or whatever else in here
  end
end

so that I could do the following:

article.name1? #would return true of article.attribute == "name1"

Is something like this possible?

Obviously this is just a simple example of one thing I might do with, but what I’m really getting at here is how to assign the method name based off a string.

Answer 1

You need Module#define_method. Check this out:

class Foo
  attr_accessor :attribute

  ARRAY = ["name1", "name2"]
  ARRAY.each do |k|
    define_method "#{k}?" do
      self.attribute == k
    end
  end
end

f = Foo.new
f.attribute = 'name1'

f.name1? # => true
f.name2? # => false