Perl: Forming array from scalar value ?

HarryD

Hi guys,

I'm trying to form a new array, the name of which is
based on the value of a scalar.
But perl don't like it:

@array_$i = ();

This will be in a loop with $i incrementing.

What I want is:

@array_1 = ();
@array_2 = ();
@array_3 = ();...etc

Any ideas ?

TIA
R

[CrimsonGhost]

A variable-variable.
I've used them in php, you'd some thing like

$varstr = "array_";
$counter = 1;

$newvar = $varstr . $counter;

$$newvar = "what ever the hell you want";

If you can use variable variables in perl it'd probably be something similar. You'd have the above some loop incrementing $counter.

A quick google for perl "variable variables" turned up
www.programmersheaven.com/ zone27/articles/article535.htm
and
www.tek-tips.com/gviewthread.cfm/pid/219/qid/868000
One of which may be some use.

Zaltais

#!/usr/bin/perl -w
use strict;

my $array;

my $i = 0;

while ($i < 10){
	$array->[$i] = (["a", "b", "c"]);
	$i++
}

print $array->[5]->[1];

Very simple example, but this creates a 'grid'.
Grid has 10 rows (0 to 9) and 3 columns (0 to 2).
Final line print's the second column of the sixth row.

Naturally you can use variables to refer to any particular 'cell' of the 'grid'.
So given the above code followed by:

my $y = 3;
my $x = 0;

print $array->[$y]->[$x];

We get the first column of the fourth row.

Bit of a headmelter to get your head round, especially given such a simple example, but take a look at 'perllol' (Manipulating Arrays of Arrays in Perl) 'perlreftut' (Perl References Tutorial) and 'perldsc' (Perl Data Structures Cookbook) - or go here and here and here.

You can also create hashes of arrays, arrays of hashes, hashes of arrays of hashes, etc., etc.

Feel free to post back with any questions.

HarryD

problem solved.. Thanks Guys :-)