i would like to spend more words on why push is prototyped

So we don't have to pass a reference for the first argument.

If there weren't a prototype, the array being passed in would be flattened:

push @array, $value;

would be equivalent to:

push $array[0], @array[1..$#array], $value;

Let's compare two subroutines with and without prototypes, and see what's in @_:

use Data::Dumper;

sub test1 (\@@) { print Dumper \@_; }
sub test2       { print Dumper \@_; }

my @array = (1,2,3);
my $value = 4;

test1( @array, $value);
test2( @array, $value);
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output should be:

$VAR1 = [
          [
            1,
            2,
            3
          ],
          4
        ];
$VAR1 = [
          1,
          2,
          3,
          4
        ];
[download]

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