Thanks all.
Again,how about the difference about a pointer and a reference?
2006/3/27, Jay Savage <[EMAIL PROTECTED]>:
>
> On 3/25/06, Practical Perl <[EMAIL PROTECTED]> wrote:
> > Hi,list,
> >
> > When a subroutine return a value,for example,this value is a pointer to
> an
> > array,which is get defined in this subroutine.When out of the
> > subroutine,some a statement call this subroutine and receive the return
> > value to a variable named as $aaa.Is $aaa a duplicate of the pointer in
> that
> > subroutine?Thanks.
> >
> > sub test {
> > @abc = qw/aa bb cc dd/;
> > return [EMAIL PROTECTED];
> > }
> >
> > my $aaa = test( );
> >
> >
>
> No. $aaa is not a duplicate of @abc, it's a refernce to @abc. If you
> change $aaa, @abc will change, too, and vice versa. Consider a
> slightly more complicated example (not that this code, like yours,
> will fail under 'use strict'):
>
> sub mytest {
> push @abc, qw/aa bb cc dd/;
> return [EMAIL PROTECTED];
> }
>
> $aaa = mytest();
> # $aaa has [aa,bb,cc,dd]
>
> mytest();
> # $aaa has [aa,bb,cc,dd,aa,bb,cc,dd]
>
> Reinitializing @abc with my each time will create a local variable for
> each instance of the subroutine, but you'll still have a refernce, not
> a copy.
>
> If you want to make a duplicate of an array, just use '='. @aray2 =
> @array1.
>
> HTH,
>
> -- jay
> --------------------------------------------------
> This email and attachment(s): [ ] blogable; [ x ] ask first; [ ]
> private and confidential
>
> daggerquill [at] gmail [dot] com
> http://www.tuaw.com http://www.dpguru.com http://www.engatiki.org
>
> values of β will give rise to dom!
>
