From: dblack@...
Date: 2002-11-09T08:38:50+09:00
Subject: Re: Multi-dimensional (like 2) arrays in Ruby

Hi --

On Sat, 9 Nov 2002, Austin Ziegler wrote:

> On Sat, 9 Nov 2002 08:18:31 +0900, Ted wrote:
> > All of the replies say the same thing -- this is good. My learning
> > project for Ruby is implementing a turning grille cipher. I want
> > to allocate a n*m matrix where n and m are read from stdin.
> >
> > I have the n[] (the rows) array, no sweat. But the m part (the
> > columns) is rather elusive.
> >
> > Here's my latest code:
> >
> > @m = Array.new(@rows)
> > @M = @m.each {|row| @m[row] = Array.new(@cols)}
>
> Try:
>
> matrix = Array.new(@rows, Array.new(@cols))

The problem with that is that each row ends up being the same
object:

  cols,rows = 3,5
  m = Array.new(rows, Array.new(cols))
  m[1][1] = "hello"
  p m[2][1]   # =>  "hello"

I'm not sure whether there's a plan afoot to enable a proc-calling
version of this (with which you could create a separate object each
time).


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav