Ruby 1.9.3 リファレンスマニュアル > ライブラリ一覧 > matrixライブラリ > Matrixクラス > each_with_index

instance method Matrix#each_with_index

each_with_index {|e, row, col| ... } -> self

[TODO]

Yields all elements of the matrix, starting with those of the first row, along with the row index and column index, or returns an Enumerator is no block given

Matrix[ [1,2], [3,4] ].each_with_index do |e, row, col|
  puts "#{e} at #{row}, #{col}"
end
  # => 1 at 0, 0
  # => 2 at 0, 1
  # => 3 at 1, 0
  # => 4 at 1, 1
class Matrix