Re: [vox-tech] perl question - arrays and lists

[Samuel Merritt <MAPSspam@andcheese.org>]

On Thu, May 08, 2003 at 01:12:43PM -0700, Peter Jay Salzman wrote:
> there's some code i wrote that does something like:
> 
> sub blah()
> {
>    foreach (@foobar)
>    {
>       push @array, ($foo, $bar);
>    }
>    
>    return @array;
> }
> 
> so i'm returning an array whose elements are each a list of two items.

Actually, you're not. The documentation for "push" says: 

Treats ARRAY as a stack, and pushes the values of LIST onto the end of
ARRAY.  The length of ARRAY increases by the length of LIST.

The above code is equivalent to:

foreach(@foobar)
{ 
    push @array, $foo; 
    push @array, $bar; 
}


> the receiving code is something like:
> 
>    my @barfoo = blah();
> 
> what i've found is that @barfoo is no longer an array of lists.  the
> lists appear to be "flattened out".
> 
> so in the previous example, if there's one element of @foobar and $foo
> is "hello" and $bar is "dolly", then what i see is:
> 
>    $barfoo[0] is "hello";
>    $barfoo[1] is "dolly";
> 
> when what i really want is;
> 
>    $barfoo[0] = ("hello", "dolly");
> 
> i know that arrays can hold lists, but i must not be doing it correctly.
> do i need to do this with references?

Yep. Try push @array, [$foo, $bar]. 

-- 
Samuel Merritt
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