me

def Inject & Me - BFFs

posted_by :Amos, :on => 'September 6th, 2008'

I find myself turning to Enumberable#inject more and more. It is such a powerful method, yet I rarely see it used in others' code. Here are a couple of examples of the power of inject.

Adding Facorial to All Integers 
class Integer
  def factorial
    raise 'Cannot take a factorial of a negative number' if self < 0
    return 1 if self == 0
    (1..self).inject { |total, element| total * element }
  end
end

Removing Touching Matching Elements in an Array Until No Touching Elements Match( thanks Eric )

class Array
  def remove_touchers
    self.inject([]) { |final, element| final[-1] == element ? final[0..-2] : final << element }
  end
end

So, why aren't there more people using this method? Is it just forgotten? Are you using Enumberable#inject? How are you using it?

tags = %w( )
{ |it| digg it }
self.add_to_delicious

end

end