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
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