From: hemant <gethemant@...>
Date: 2007-02-16T01:23:02+09:00
Subject: Re: is it behaving strange ?

On 2/15/07, sur max <sur.max@gmail.com> wrote:
> ok and its like ....
>
> *a = 9

remember a would become an array here.because as explained above,if
lvalue is prefixed with asterisk, then rvalue is collected and
assigned to lvalue as an array.

> a << 5

append 5 to a (which is an array)

> b = *a # => [9,5]
> is there any relation in this n above ?

Now, above is pretty standard ruby behaviour, it has nothing to do
with * operator, as usual * extracts the values from a(which was an
array).

For example:

irb(main):062:0> b = 9,5
[9, 5]
irb(main):063:0> b
[9, 5]
irb(main):064:0> b,c = 9,5
[9, 5]
irb(main):065:0> b
9
irb(main):066:0> c
5




>
> On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
> >
> > Hi --
> >
> > On Fri, 16 Feb 2007, hemant wrote:
> >
> > > On 2/15/07, sur max <sur.max@gmail.com> wrote:
> > >> *a = 9     # => [9]
> > >> a     # => [9]
> > >> *a    # => compile error
> > >> *b=*a    # => [9]
> > >> *b = a    # => [[9]]
> > >> b = a    # => [9]
> > >> b = *a    # => 9 ----- this is amazing ?
> > >
> > > Splat operator is amazing, but above behaviour can be explained using
> > this:
> > >
> > > "If the last lvalue is preceded by an asterisk, all the remaining
> > > rvalues will be collected and
> > > assigned to that lvalue as an array. Similarly, if the last rvalue is
> > > an array, you can
> > > prefix it with an asterisk, which effectively expands it into its
> > > constituent values in
> > > place. (This is not necessary if the rvalue is the only thing on the
> > > right side�the array
> > > will be expanded automatically.)
> > > "
> > > See, nothing wierd out there. ;)
> >
> > Another way to look at it, which I think covers all of the above
> > cases, is:
> >
> >    *x equals [x] without the []
> >
> > So:
> >
> >    *a = 9   # a without the [] is 9, so a == [9]
> >    *b = a   # b without the [] is [9], so b == [[9]]
> >    b = *a   # b == [9] without the [], so b == 9
> >
> >
> > That's why I call it the "unary unarray" operator.
> >
> >
> > David
> >
> > --
> > Q. What is THE Ruby book for Rails developers?
> > A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black)
> >     (See what readers are saying!  http://www.rubypal.com/r4rrevs.pdf)
> > Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
> > A. Ruby Power and Light, LLC (http://www.rubypal.com)
> >
>
>
>
> --
> sur
> http://expressica.com
>


-- 
gnufied
-----------
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.
http://people.inxsasia.com/~hemant