P1:_Enumerables_solution.rb

# Solution for Challenge: P1: Enumerables. Started 2013-06-25T21:26:00+00:00
#
# Objective 1
# 
# Array#map     iterates through an array, transforms the elements, and returns a new array
# Array#inject  combines all arrays from an array onto one return value by performing an operation a mathematical operation. The inject corresponds to the base value that you use for further operations. You inject this into the array. Another name for this enumerable method is reduce
# Array#select  filter an array and returns a new one
# yield         method yields control and uses the output of a bloc
#
class Array
  def my_map             # or other enumerable method
    output = []
    self.each do |e|
     output << yield(e) 
    end
    output
  end
end
puts [1,2,3,4].my_map { |i| i -= 1 }  == [0,1,2,3]