From: Robert Klemme <shortcutter@...>
Date: 2008-05-13T22:08:51+09:00
Subject: Re: Convert integer to array?

2008/5/13 Rob Biedenharn <Rob@agileconsultingllc.com>:
>
>
>  On May 13, 2008, at 7:26 AM, Robert Klemme wrote:
>
>
> > 2008/5/12 Sebastian Hungerecker <sepp2k@googlemail.com>:
> >
> > > Nadim Kobeissi wrote:
> > >
> > > > Let's say I have:
> > > > x=1234
> > > > How can I convert that to the follow array:
> > > > x=[1, 2, 3, 4]
> > > >
> > >
> > > A solution that doesn't use strings:
> > >
> > > result_array = []
> > > while x > 0
> > >  result_array.unshift x % 10
> > >  x /= 10
> > > end
> > > result_array
> > >
> > > This will "destroy" x, though.
> > >
> >
> > Well, that's easily fixed: just work with another variable.  You can
> > also combine division and mod:
> >
> > def int_split(x)
> >  r = []
> >  y = x
> >  while y > 0
> >   y, b = y.divmod 10
> >   r.unshift b
> >  end
> >  r
> > end
> >
> > Kind regards
> >
> > robert
> >
> > -- use.inject do |as, often| as.you_can - without end
> >
>
>  def int_split(x)
>   return [0] if x.zero?
>   r = []
>
>   while x > 0
>     x, b = x.divmod 10
>     r.unshift b
>   end
>   r
>  end
>
>  You don't need y since Fixnums are immediate.

The reasoning is wrong but comes to the right conclusion: if you want
to retain the original value of x then it does not matter whether
values are mutable or not. It is sufficient to assign to x to loose
the original value.

In my code I don't need y because x is a method parameter.  My remark
was a reaction to Sebastian's comment and piece of code which modified
x.

>  It still doesn't work for negative numbers, but since that behavior hasn't
> been defined, it's left as an exercise for the OP.

Exactly. :-)

Kind regards

robert

-- 
use.inject do |as, often| as.you_can - without end