By default, $a and $b will be with us forever (in perl5) for backward compatibility; however, since 5.6.0, perl has supported having a named comparison routine with a $$ prototype to indicate that you want the elements to sort passed as parameters instead of as $a and $b: 
$ perl -we'sub evenfirst ($$) { ($_[0]&1) <=> ($_[1]&1) or $_[0] <=> $
+_[1] }
print sort evenfirst 0..9'
0246813579

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In reply to Re: Why do we need $a and $b to be special? by ysth
in thread Why do we need $a and $b to be special? by rinceWind

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