CODEWITHSUNDEEP
rubymultidimensional-array
scobo
scobo

Reputation: 197

Ruby: Select element from multidimensional array which matches a given block

I am building a Chess program in Ruby and my Square objects are in a multi-dimensional array.

Example code for Square class:

class Square
  attr_accessor :piece_on_square, :x, :y, :coordinates
  def initialize(piece_on_square=nil, x=nil, y=nil, coordinates=nil)
    @piece_on_square = piece_on_square
    @x = x
    @y = y
    @coordinates = coordinates
  end
end

Code within my Board class:

@square_array = Array.new(8){Array.new(8){Square.new}}

The problem comes when I try to select a Square object in the @square_array which matches a condition (such as a Square with coordinates of "a4"). I've tried using nested #each_with_index calls with #select but that isn't working. I've only been able to select the array itself, not the object in the array. What's the best way to do this?

Upvotes: 0

Views: 662

Answers (1)

sawa
sawa

Reputation: 168249

I see many people building nested arrays for doing this kind of thing, encountering various problems that stem from using nested arrays. The obvious solution is: get rid of nested arrays, and use a flat array.

If I were to do such programming, I would use a flat array, and do row/column operations using the array index and modulo operations (Fixnum#% for columns, Fixnum#/ for rows).

But in your case, you seem to be saving the column and row numbers, and even the coordinate name, for each square, so it is easier for you to use a flat hash with either the row-column combination or the coordinate name as the key.

Upvotes: 3

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