There are of course many other ways to do this. Here is one.

#!/usr/local/bin/perl5.6.0 -w
use strict;

# array of records
my @contact_type =
(
    'N(8) -- H(15) .. O(9)',
    'N(8) -- H(15) .. N(8)',
    'N(8) -- H(16) .. O(9)',
);


my %count_hash;  # used to store matching lines

for (  map { [ /(H\(\d+\))/, $_ ] } @contact_type  )
{
    push( @{$count_hash{$_->[0]}}, $_->[1] );
}


for ( keys %count_hash )
{
    if (  scalar( @{$count_hash{$_}} ) > 1  )
    {
        print qq{$_\n} for ( @{$count_hash{$_}} );
    }
}

[download]

Output:
:!./test.pl
N(8) -- H(15) .. O(9)
N(8) -- H(15) .. N(8)

[download]
Wonko

In reply to Re: duplicate lines in array by Wonko the sane
in thread duplicate lines in array by harry34

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.