starbolin writes:
This code: push(@{$matchedfiles[$c]}, [ ... ]); Is incorrect. ...
But I don't see a problem with auto-vivification in this case. Consider this test code: 
use Data::Dumper;
my @m;
my $c;

$c = 3;
push(@{$m[$c]}, [ 'foo' ]);

$c = 2;
push(@{$m[$c]}, [ 'bar' ]);

print Dumper(\@m), "\n";
for (0..3) {
  print "length of m[$_] = ", scalar(@{$m[$_]}), "\n";
}

[download]
The first push not only creates $m[3] as an array ref, but also sets $m[0], $m[1] and $m[2] to undef. The second push changes $m[2] from undef to a new array ref.

The last for loop shows that undef is basically indistinguishable from [], i.e. a reference to an empty array.

In reply to Re^2: Uninitialized value in concatenation (.) or string? by pc88mxer
in thread Uninitialized value in concatenation (.) or string? by jbush82

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