Multidimensional Array

burgerw has asked for the wisdom of the Perl Monks concerning the following question:

Hi,
I've playing around with a multidimensional array and found something that confusses me royally.
What is so special about $a_final[1][1][0][0] in the following snippet?
I can assign all the other elements (or at least, all I've tested). But not this one.
Can you help me?
Thank you very much.
burgerw

@a_1 = ();
@a_2 = ();
@a_3 = ();   
@a_4 = ();   
@a_a = (\a_4, \a_3);
@a_b = (\@a_2, \a_a);
@a_final = (\@a_1, \@a_b);

#These do work:
       $a_final[0][1][0][0] = "x";
print "$a_final[0][1][0][0]\n";

       $a_final[1][0][0][0] = "x";
print "$a_final[1][0][0][0]\n";

       $a_final[1][2][0][0] = "x";
print "$a_final[1][2][0][0]\n";

# This won't work:
# error message: "Not an ARRAY reference"
       $a_final[1][1][0][0] = "x";
print "$a_final[1][1][0][0]\n";
[download]

Comment on Multidimensional Array Select or Download Code

Replies are listed 'Best First'.
Re: Multidimensional Array by everybody (Scribe) on Apr 15, 2010 at 13:08 UTC
The reason it's saying "Not an ARRAY reference" is because it's not an array reference. Add the missing sigils, and the error disappears: `... @a_a = (\@a_4, \@a_3); @a_b = (\@a_2, \@a_a); ...` [download]	[reply] [d/l]
Re: Multidimensional Array by toolic (Bishop) on Apr 15, 2010 at 13:09 UTC
`@a_a = (\a_4, \a_3); @a_b = (\@a_2, \a_a);` [download] You did not use references to your a_4, a_3 and a_a arrays. You probably meant to do this: `\| \| V V @a_a = (\@a_4, \@a_3); @a_b = (\@a_2, \@a_a); ^ \|` [download] You would have had a clue something was wrong had you use strict and warnings.	[reply] [d/l] [select]
Re: Multidimensional Array by choroba (Cardinal) on Apr 15, 2010 at 13:14 UTC
Missing @ at `\a_a`. Use syntax highlighting or Data::Dumper.	[reply] [d/l]
Re^2: Multidimensional Array by burgerw (Initiate) on Apr 15, 2010 at 13:21 UTC
0_0 You guys are fast. Thank you everybody Thank you toolic Thank you Anonymous Monk Thank you choroba You four have saved my day.	[reply]
Re: Multidimensional Array by Anonymous Monk on Apr 15, 2010 at 13:10 UTC
`use Data::Dump::Streamer; @a_1 = (); @a_2 = (); @a_3 = (); @a_4 = (); @a_a = (\a_4, \a_3); @a_b = (\@a_2, \a_a); @a_final = (\@a_1, \@a_b); Dump(\@a_final); __END__ $ARRAY1 = [ [], [ [], \do { my $v = 'a_a' } ] ];` [download] Use strict warnings and diagnostics or die	[reply] [d/l]
Re: Multidimensional Array by burgerw (Initiate) on Apr 15, 2010 at 13:26 UTC
0_0 You guys are fast. Thank you everybody Thank you toolic Thank you Anonymous Monk Thank you choroba You four have saved my day.	[reply]