Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot

Re: Selecting particular key-value pairs in hashes

by pbeckingham (Parson)
on Sep 18, 2004 at 17:05 UTC ( #392006=note: print w/replies, xml ) Need Help??

in reply to Selecting particular key-value pairs in hashes


my %hash2 = map {$_ => $hash{$_}} grep {/^\d+_\d+$/} keys %hash;

pbeckingham - typist, perishable vertebrate.

Replies are listed 'Best First'.
Re^2: Selecting particular key-value pairs in hashes
by Aristotle (Chancellor) on Sep 18, 2004 at 20:34 UTC

    You can pick more than one value at a time out of a hash — see merlyn's code and gaal's remark.

    my %hash2 = @hash{ grep /\d+_\d+/, keys %hash };

    Update: thanks to bobf for notifying me that this code makes, uh, very little sense. Here's a hash slice incantation that actually works:

    my %hash2; @hash2{ @$_ } = @hash{ @$_ } for [ grep /\d+_\d+/, keys %hash ]; # or more verbosely my %hash2; { my @key = grep /\d+_\d+/, keys %hash; @hash2{ @key } = @hash{ @key }; }

    Makeshifts last the longest.

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://392006]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others scrutinizing the Monastery: (5)
As of 2017-06-28 15:14 GMT
Find Nodes?
    Voting Booth?
    How many monitors do you use while coding?

    Results (640 votes). Check out past polls.