Re: Storing unique values

This should do what you're looking for:

#!/perl/bin/perl

use warnings;
use strict;

my @arr = qw(AB1 BX6 WF2 CB7 EZ6 WY2 AB1 AB1 WF2 ET9);

my $hash = {};

for my $cur (@arr) {
    if (exists($hash->{$cur})) {
        $hash->{$cur}++;
    }
    else {
        $hash->{$cur} = 1;
    }
}

my @unique = sort keys %$hash;
for (@unique) {
  print sprintf qq(Value "%s" occurred %d times.\n), $_, $hash->{$_};
}
[download]

As you parse through the source array, you can just check for existence in the %$hash, and then process/ignore as necessary.

Where do you want *them* to go today?

Comment on Re: Storing unique values Download Code

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Re^2: Storing unique values by Aristotle (Chancellor) on Jan 18, 2003 at 20:28 UTC
`if (exists($hash->{$cur})) { $hash->{$cur}++; } else { $hash->{$cur} = 1; }` [download] No need to jump through hoops. Perl doesn't complain when increasing undefined variables, so this will do: `$hash->{$cur}++;` [download] It's the accept practice for this case, in fact, so it should be done this way as well. Makeshifts last the longest.	[reply] [d/l] [select]