No.

$# returns the subscript of the last element in an array. So if you'd have an array called @array with six elements, $#array would return 5:

qw(one two three four five six);
print $array[$#array]; # prints "six"
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$j[$#j+1] = ("another");
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is actually just obfuscation for this:

push @j, "another";
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