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

Re: to select unique characters

by kyle (Abbot)
on Feb 13, 2008 at 17:53 UTC ( #667791=note: print w/replies, xml ) Need Help??


in reply to to select unique characters

Here's an even shorter way, if you don't want to use a variable at all:

my @uniq = keys %{{ map { $_ => undef } @proc_name1 }};

However, this is slower than the slice and grep methods, both.

use strict; use warnings; use Benchmark q{cmpthese}; my @arr = ( q{a} .. q{z} ) x 1_000; cmpthese( -10, { useGrep => sub { my %seen; my @out = grep { !$seen{$_}++ } @arr; return @out; }, useSlice => sub { my %seen; @seen{@arr} = (); my @out = keys %seen; return @out; }, useRef => sub { my @out = keys %{ { map { $_ => undef } @arr } }; return @out; }, } );
Rate useRef useGrep useSlice useRef 74.3/s -- -64% -84% useGrep 204/s 175% -- -56% useSlice 464/s 525% 127% --

(Thanks to johngg for the tests in Re: to select unique characters).

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://667791]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others meditating upon the Monastery: (4)
As of 2021-03-07 12:33 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    My favorite kind of desktop background is:











    Results (121 votes). Check out past polls.

    Notices?