Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic
 
PerlMonks  

Re: diff of two hashes.

by Russ (Deacon)
on May 12, 2000 at 20:59 UTC ( #11320=note: print w/replies, xml ) Need Help??


in reply to diff of two hashes.

<Updated>
I like nuance's idea (above). I now store undef as the value when a key is missing from one hash. See nuance's description above for an explanation of the "return" values.
</Updated>

Here's some punctuation for you:

(This is a short, concentrated way to do it - only 4 lines)

# Keys 7 and 8 are unique, keys 2,4 and 6 have different values my %R = (1=>1, 2=>2, 3=>3, 4=>4, 5=>5, 6=>6, 7=>7); my %S = (1=>1, 2=>'b', 3=>3, 4=>'d', 5=>5, 6=>'f', 8=>8); # 1) Keys in %R which are not in %S # 2) Keys in %S which are not in %R # 3) Keys in both which have different values my %Diffs = ((map(($_ => [$R{$_}, undef]), grep {not exists $S{$_}} k +eys %R)), (map(($_ => [undef, $S{$_}]), grep {not exists $R{$_}} k +eys %S)), (map(($_ => [$R{$_}, $S{$_}]), grep {exists $S{$_} and $R{$_} ne $S{$_}} keys %R)) +); # Print out what we found for (sort keys %Diffs){ print $_, ': ', join(', ', map(defined $_ ? $_ : 'undef', @{$Diffs{$ +_}})), "\n"; }
A couple points to note:
  • if your values are numeric, change the 'ne' in the third Diffs section
  • we use an anonymous array ref to store the values in %Diffs, so remember to dereference it when you use %Diffs

Enjoy!

Russ

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://11320]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others chilling in the Monastery: (4)
As of 2019-07-16 18:10 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?