# [ARRAYS] Bidimensional Arrays? (opened)

Discussion in 'Ruby' started by Flaab Mrlinux, Nov 14, 2006.

1. ### Flaab MrlinuxGuest

Hi there!

I'm just new at ruby and I have a weird issue probably really dumb but i
just haven't been able to figure it out.

Using arrays in C or whatever i could define an array using to indexing
numbers, in order to simulate a chess board or whatever...

board = array[8,8]

And then store info in that array like this

board[1,1] = whatever.

I just can't get that to work in ruby! Why? How can i do it?

Thx

--
Posted via http://www.ruby-forum.com/.

Flaab Mrlinux, Nov 14, 2006

2. ### Tim PeaseGuest

On 11/14/06, Flaab Mrlinux <> wrote:
> Hi there!
>
> I'm just new at ruby and I have a weird issue probably really dumb but i
> just haven't been able to figure it out.
>
> Using arrays in C or whatever i could define an array using to indexing
> numbers, in order to simulate a chess board or whatever...
>
> board = array[8,8]
>
> And then store info in that array like this
>
> board[1,1] = whatever.
>
> I just can't get that to work in ruby! Why? How can i do it?
>

The ruby Array class is always a one dimensional array. You can create
an array of arrays to get two dimensional behavior.

ary = Array.new(3) {|idx| Array.new(3)}
ary[0][0] = 1

To make the indexing a little more clear

tmp =ary[0] # give me the row at index 0
tmp[0] = 1 # set the value at column 0 of row 0 to 1 (since
tmp is really row 0)

But usually you can just glom all that together like so ...

ary[0][0] = 1
ary[0][1] = 2
ary[0][2] = 3

TwP

Tim Pease, Nov 15, 2006

3. ### Timothy HunterGuest

Flaab Mrlinux wrote:
> Hi there!
>
> I'm just new at ruby and I have a weird issue probably really dumb but i
> just haven't been able to figure it out.
>
> Using arrays in C or whatever i could define an array using to indexing
> numbers, in order to simulate a chess board or whatever...
>
> board = array[8,8]
>
> And then store info in that array like this
>
> board[1,1] = whatever.
>
> I just can't get that to work in ruby! Why? How can i do it?
>
> Thx
>
>

The easiest way to define a multidimensional array in Ruby is to define
an array of arrays:

board = Array.new(8) { Array.new(8) }

Run "ri Array.new" to read about how to create and initialize arrays.

Timothy Hunter, Nov 15, 2006