Intro to Monkey Patching

Monkey patching have it’s legitimate uses, such as monkey patching float and fixnum to return money (currency jobs).

Or… you could monkey patch fixnum to play “FizzBuzz” for you:

Fixnum

class Fixnum
 def divisible_by_three?
  self % 3 == 0
 end
end

Testing

3.divisible_by_three? # => true
4.divisible_by_three? # => false

More Fixnum

class Fixnum
 def fizzbuzz
  return “Fizz” if divisible_by_three?
  self
 end
end

More Testing

3.fizzbuzz # => "Fizz"
1.fizzbuzz # => 1

Rewriting Ruby inject method by monkey patching Array class

This is my attempt at reimplementing Ruby’s Array.inject method:

Reinventing the wheel

class Array
 # block.call approach
 def injectiano(accumulator = nil,&block)
  collection = self.dup

  accumulator ||= collection.shift
  collection.each do |item| 
   accumulator = block.call(accumulator,item)
  end	
  accumulator
 end
end

There you have it. With great power comes great responsibility.