|Just another Perl shrine|
Re: Anonymous Data Structures: How Do They Work?by orkysoft (Friar)
|on Jan 14, 2002 at 01:11 UTC||Need Help??|
When there is nothing that references a data structure, it will go away. You can't access it, so it's not needed anymore.
Consider this: my $array = [1,2,3];
$array is a scalar -- it is a reference to the anonymous array created with [1,2,3]. It'll have an internal name like ARRAY(0x80cb8fc) or something, which is what is put in $array: try printing it, you'll see a string like that.
This is called a reference, it is magic. You can't just assign $array = "ARRAY(0x80cb8fc)"; and expect it to behave like a reference. It'll be just another string this way.
You can however, say:
In this example, both $array and $alias point to the same anonymous array.
You can also say something like:
Which will print the contents of the array.
I recommend you read the References tutorial for more information.
The [1,2,3] array is anonymous, since it never gets a name. The reference to it, $array, has a name, but that's not the name of the array itself.
You'll want to use things like this for building e.g. a two-dimensional array, or an array of hashes, or a hash of arrays.