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Re: size of an array ref

by roboticus (Chancellor)
on Feb 24, 2012 at 13:03 UTC ( #955911=note: print w/replies, xml ) Need Help??


in reply to size of an array ref

fionbarr:

You need to use scalar(@{$a[0]}) to get 3. Your array contains only one element, the array reference. So if you want 3, you need to ask the referenced array for its size, not the container. Perhaps this example will help:

$ cat t.pl #/usr/bin/perl use strict; use warnings; use Data::Dumper; my @a = (1, 2, 3); print "Size of a: ", scalar(@a), "\n"; print Dumper(\@a),"\n"; my @b = [0, 1, 2]; print "Size of b: ", scalar(@b), "\n"; print Dumper(\@b),"\n"; print "Size of b[0]: ", scalar(@{$b[0]}), "\n"; print Dumper($b[0]),"\n";

which gives us:

$ perl t.pl Size of a: 3 $VAR1 = [ 1, 2, 3 ]; Size of b: 1 $VAR1 = [ [ 0, 1, 2 ] ]; Size of b[0]: 3 $VAR1 = [ 0, 1, 2 ];

...roboticus

When your only tool is a hammer, all problems look like your thumb.

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Re^2: size of an array ref
by fionbarr (Friar) on Feb 24, 2012 at 13:11 UTC
    that's it! Thanks guys! # array: $ perl -wE 'my @a = qw/a b c/; say scalar @a' 3 # array ref: $ perl -wE 'my $a = qw/a b c/; say scalar @$a'perfect!

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