Method: Array#step

Defined in:

lib/core/facets/array/step.rb

#step(n) ⇒ Object

Iterate over every nth element of an array.

r = []
[:a, :b, :c, :d].step(2) { |x| r << x }
r   #=> [:b, :d]

Without a block it returns an Enumerator.

[:a, :b, :c, :d].step(1).to_a   #=> [:a, :b, :c, :d]
[:a, :b, :c, :d].step(2).to_a   #=> [:b, :d]
[:a, :b, :c, :d].step(3).to_a   #=> [:c]
[:a, :b, :c, :d].step(5).to_a   #=> []

CREDIT: Ryan Duryea

# File 'lib/core/facets/array/step.rb', line 18

def step(n) #:yield:
  if block_given?
    ((n - 1)...size).step(n).each do |i|
      yield(fetch(i))
    end
  else
    Enumerator.new(size / n) do |y|
      ((n - 1)...self.size).step(n).each { |i| y << fetch(i) }  
    end
  end
end