Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery

How can I get the unique keys from two hashes?

by faq_monk (Initiate)
on Oct 08, 1999 at 00:20 UTC ( #631=perlfaq nodetype: print w/replies, xml ) Need Help??

Current Perl documentation can be found at

Here is our local, out-dated (pre-5.6) version:

First you extract the keys from the hashes into arrays, and then solve the uniquifying the array problem described above. For example:

    %seen = ();
    for $element (keys(%foo), keys(%bar)) {
    @uniq = keys %seen;

Or more succinctly:

    @uniq = keys %{{%foo,%bar}};

Or if you really want to save space:

    %seen = ();
    while (defined ($key = each %foo)) {
    while (defined ($key = each %bar)) {
    @uniq = keys %seen;

Log In?

What's my password?
Create A New User
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others examining the Monastery: (7)
As of 2016-10-24 20:58 GMT
Find Nodes?
    Voting Booth?
    How many different varieties (color, size, etc) of socks do you have in your sock drawer?

    Results (309 votes). Check out past polls.