>>>>> "PP" == Philip Potter <philip.g.pot...@gmail.com> writes:
PP> I found this code example on Stack Overflow to prettyprint a hash: PP> (link: PP> http://stackoverflow.com/questions/2431032/how-to-print-a-key-value-using-the-perl-hases/2431139#2431139 PP> ) you shouldn't be learning perl from that site! PP> my %hash = (2009 => 9, 2010 => 10); see what happens when you have 3 or more pairs in that hash! PP> print join (" => ", each %hash), "\n" while <keys %hash>; try doing a perl one liner with -MO=Deparse and see what perl parses that as. PP> My question is: what is the angle bracket operator doing? I know its PP> use as <FILE>, <$file>, and <*.glob>, but I've never seen it used like PP> this, and I can't see anything in perlop#I/O Operators which would PP> help. This code works on perl 5.8.8 so it's been a feature for some PP> time, so it would surprise me if it's not documented anywhere, but I PP> just can't find it. it is just a glob which expands to the files that match or just the tokens it is passed if no expansions happen. so that is doing a while loop for 2 iterations (hence my comment about 3 or more pairs in the hash). it is just a very stupid and broken example posted on that site. even if the <> did something to do with hashes, why would you loop over the keys AND also call each? the proper way to simple loop over a hash is to use each and get both the key and value at one time: while( my( $key, $val ) = each %hash ) { print "$key => $val\n" ; } that loops properly and for all the key/value pairs in the hash. uri -- Uri Guttman ------ u...@stemsystems.com -------- http://www.sysarch.com -- ----- Perl Code Review , Architecture, Development, Training, Support ------ --------- Gourmet Hot Cocoa Mix ---- http://bestfriendscocoa.com --------- -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
