This particular trick is likely to confuse C programmers who are used to negative array indexes meaning the elements that come before zero, such as they do in the integer number space.

Perl orients negative offsets from the end of the array, or the nth element, not from the 0th element.

As such: 
    my (@stuff) = qw [ one two three four five ];

    print join (',', $stuff[-2], $stuff[2]);

[download]
Returns:     four,three I always wondered what assigning to $x[-1] would do in Perl.

Further, using a little regression, the following can be derived: 
      my (@ans) = qw [ false true ];

      print $ans[ !!(assertion) ];

[download]

In reply to Re: Fun With Spaceship by tadman
in thread Fun With Spaceship by japhy

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