SPUG: removing array from "array of arrays"

[Joel Grow]

On Tue, 12 Jun 2001, weaver wrote:

> I have: @args = ("arg1", "arg2", "arg3");
>
> for($i = 1; $i < $something; $i++)
> {
>   push @args_list, @args;       # or push @args_list, [ @args ];
> }
>
> and in a subroutine would like to remove the @args that I pushed onto
> @args_list during one loop iteration, WITHOUT KNOWING THE # OF
> ELEMENTS ASSIGNED TO @args.  In other words, I DON'T want to use:
>
> @var = @_[0, 1, 2];
>
> or anything of this nature.
>
> How can I do this, can it be done?


There is a big difference between

 push @args_list, @args;

and

 push @args_list, [ @args ];

The former first expands @args into a list and then pushes each element
into @args_list--you do *not* get an array of arrays, just one giant
array.

The latter pushes one element into @args_list for each iteration of the
loop, a reference to an array containing the elements of @args.  This is
an array of arrays, and is a good way to solve your problem.

your code might look something like this:

 for($i = 1; $i < $something; $i++)
 {
   push @args_list, [ @args ];
 }

 # then, later on when you want to process @args_list...

 for my $ra_args ( @args_list ) {
   process($ra_args);
 }

 sub process {
   my $ra_args = shift;

   for my $arg ( @$ra_args ) {
     print "I found an arg: $arg\n";
   }
 }

 __END__

$Joel


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