Re: Unique elements in array

It's better if you can avoid an unnecessary intermediary array, e.g. in a typical case of reading ids from the first column in a tsv file, I'd go for something like:

my %unique;
my @ids = map
{ chop;
  my @fld = split /\t/;
  !defined(  $unique{ $fld[0] } ) && $unique{ $fld[0] }++ && $fld[0];
} <$fileHandle>;
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Comment on Re: Unique elements in array Download Code

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Re^2: Unique elements in array by chromatic (Archbishop) on May 09, 2007 at 17:28 UTC
Ouch. chop is almost always wrong (what if your EOL marker is more than one character)--and what if `$fld[0]` is a valid value that evaluates to false in boolean context?	[reply] [d/l]
Re^3: Unique elements in array by Moron (Curate) on May 10, 2007 at 09:55 UTC
The popular misuse of chomp() deserves a new topic. As for $fld[0] - defined( unique{ $fld[0] } ) will be true in the case you cite. There might be functional issues or data quality issues in any real example but these are in general OT. __________________________________________________________________________________ ^M Free your mind!	[reply]