http://qs321.pair.com?node_id=188986

chuleto1 has asked for the wisdom of the Perl Monks concerning the following question:

Help Monks!
I would like to know how to have my @array keep one instace of repeated elements. (e.g.)

my @array = qw( foo bar match zoot zoot match match match ) ;

#do something here to the array

print @array;
Out put: foo bar match zoot

thank you
  • Comment on Having repeated intances become one in Array

Replies are listed 'Best First'.
Re: Having repeated intances become one in Array
by mephit (Scribe) on Aug 09, 2002 at 18:08 UTC 
    my @array = qw( foo bar match zoot zoot match match match ); 
@array = grep { ! $hash{$_}++} @array;

    [download]
    Check 'perldoc -q duplicate'

    --

    There are 10 kinds of people -- those that understand binary, and those that don't.

[reply]
[d/l]
Re: Having repeated intances become one in Array
by vek (Prior) on Aug 09, 2002 at 18:05 UTC
    There are a couple of different ways to handle your dilemma , here's one method using a hash to keep track of what you've already seen: 
    my %seen;
for my $foo (@array) {
   print $foo unless $seen{$foo}++;
}

    [download]
    -- vek --
[reply]
[d/l]
Re: Having repeated intances become one in Array
by ehdonhon (Curate) on Aug 09, 2002 at 18:37 UTC
[reply]
Re: Having repeated intances become one in Array
by tadman (Prior) on Aug 09, 2002 at 18:56 UTC 
    #!/usr/bin/perl

my @array = qw[ foo bar baz bar foo baz baz bad ];

sub dedupe
{
        ${_}=do{{},[],{}};@{${_}}{@_,%_,@_}=$|;keys%{\%{${_}}}
}

print dedupe(@array);

    [download]
[reply]
[d/l]
      i'm just a novice in perl...could you please explain how your code works ? i'm sure i could learn a lot from your code thanks :-)
[reply]

Back to Seekers of Perl Wisdom