DirtyInformation

Inject & Me - BFFs

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 Factorial 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?

The Past

• Testing Named Agents 03 Feb 2017
• Two Duplication Refactorings in Elixir 18 Jan 2017
• B is for BigDecimal 24 Sep 2014
• A is for Abbrev 02 Sep 2014
• Missed Chances 15 Aug 2014
• Style Guides are Failures 15 Jun 2014
• What is BDD anyway? 15 Apr 2014
• An Agile Contract 31 Mar 2014
• What Do I Want 23 Mar 2014
• Just the Tip 16 Mar 2014
• Important Partnerships 11 Mar 2014
• Lost in Translation 03 Mar 2014
• Story Splitting Revisited 23 Feb 2014
• Let your yes be yes and your no be no 16 Feb 2014
• Lethal Injection 09 Feb 2014
• Smaller is Better 02 Feb 2014
• A Second Time 26 Jan 2014
• Introspective 20 Jan 2014
• Self Reflection for the Win 06 Dec 2013
• Why? Why? Why? 30 Sep 2013
• A New Gig 18 Sep 2013
• Exceptional Comments 15 Jun 2013
• Role Objects in Acceptance Tests 30 Apr 2013
• Open Closed Ruby Woes 28 Apr 2013
• Write Something 12 Apr 2013
• A Great Cast of Characters 06 Mar 2012
• When is the Release Party? 19 Aug 2011
• Single Responsibilty, How Did I Forget You 12 Apr 2011
• Change Classes not Styles 05 Nov 2010
• My MongoDB Cookbook Recipe 20 Jul 2010
• Agile Says What? 05 Nov 2009
• Inject & Me - BFFs 07 Sep 2008