three dimensional arrays

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

Hi, I hope I won't only get 'read perllol' as reply to my question as I have already done so.
I try to build up a three dimensional array using the push command. In perllol this is described for an array of arrays:
push @AoA, [ @tmp ]; Can I use push to append an array to an array of arrays? E.g something like:
push @AoA[$i], [ @tmp ]; Or could I use $#AoA[$i] in some way to determine the last index of @AoA[$i] to then add the temp array with:

        foreach (@tmp) {
          push @AoA[$i][$#AoA[$i]+1], $_;
        }
[download]

Thanks 'varray' much for any help!

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Re: three dimensional arrays by Abigail-II (Bishop) on Nov 28, 2003 at 14:49 UTC
Some rules: 1) the first argument of push must have a @ sigil. 2) Whenever I have a sigil followed by a variable name in Perl, I may replace the variable name with a block that returns a reference of the appropriate type. So, what I want is: `push @somearray, [@tmp];` [download] But what should somearray be? Well, it should be a block returning a reference to the right array - and what is that array? It's `$AoA [$i]`. So, replacing `somearray` with the block, we get: `push @{$AoA [$i]}, [@tmp];` [download] Abigail	[reply] [d/l] [select]
Re: three dimensional arrays by Hena (Friar) on Nov 28, 2003 at 14:26 UTC
Its always good to read docs anonymous monk above mentioned important docs. But to push to 3-dimension, it should go like this `# push @tmp into 3rd dimension push (@{$AoA[$i]},@tmp); # push @tmp cell to 3rd dimension # testing for proper info, not tested foreach (@{$AoA}) { next if (defined($_) && ref($_)!="ARRAY"); push (@{$_},shift @tmp); }` [download] Remember to make sure the cell of array you are pushing into is either undefined or array reference.	[reply] [d/l]
Re: three dimensional arrays by Anonymous Monk on Nov 28, 2003 at 14:13 UTC
read perllol, and then what perllol tells you to read(SEE ALSO perldata(1), perlref(1), perldsc(1)). Now for the advice, yes, you can use push.	[reply]
Re: three dimensional arrays by Anonymous Monk on Nov 28, 2003 at 14:22 UTC
`#!/usr/bin/perl -wl - use strict; my @a; $a[0][0][0] = 0; $a[0][0][1] = 1; $a[1][0][0] = 2; $a[2][0][0] = 3; print $#a; print $a[0]; print $#{$a[0]}; print $a[0][0]; print $#{$a[0][0]}; print $a[0][0][0]; print $/; print $a[1]; print $#{$a[1]}; print $a[1][0]; print $#{$a[1][0]}; print $a[1][0][0]; __END__ 2 ARRAY(0x1abf1ac) 0 ARRAY(0x1abf1d0) 1 0 ARRAY(0x1ab51fc) 0 ARRAY(0x1ab522c) 0 2` [download]	[reply] [d/l]
Re: Re: three dimensional arrays by Anonymous Monk on Nov 28, 2003 at 14:26 UTC
`#!/usr/bin/perl -wl - use strict; my @a = ( [ [ 0, 1 ] ], [ [ 2 ] ], [ [ 3 ] ] ); print $#a; print $a[0]; print $#{$a[0]}; print $a[0][0]; print $#{$a[0][0]}; print $a[0][0][0]; print $/; print $a[1]; print $#{$a[1]}; print $a[1][0]; print $#{$a[1][0]}; print $a[1][0][0]; __END__ 2 ARRAY(0x1abf1dc) 0 ARRAY(0x1abf0f8) 1 0 ARRAY(0x1ab5214) 0 ARRAY(0x1ab51cc) 0 2` [download]	[reply] [d/l]