Question

I am looking for some help in one senario.

Requirement:

Through some validation, I have strored following kinds of value in one array.

@array_name = ("Rajesh","Raju","Ram","John","peter");

Now I know from some background that “Rajesh”, “Ram”, “peter”, are duplicate entries so I would expect my output to be:

@array_name = ("Rajesh","Raju","John");
# or 
@array_name = ("Ram","Raju","John");
# or 
@array_name = ("peter","Raju","John");

I have done example program such as below but it does not satisfy me…

    my $spcific_output ="";
    my $output ="";

    foreach my $name (@array_name) 
    {
        if($name eq "Rajesh" || $name eq "Ram" || $name eq "peter")
        {
            $spcific_output = "Rajesh and Ram and peter");
        }
        else
        {
            $output .= "My Name is $name";
        }
    } 
    $output .= $spcific_output;

Any best way to achieve this?

Answer 1

If you’re using v5.10 or higher you can use smart matching on an array with your duplicate names:

#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;

my @names = qw(Rajesh Raju Ram John Peter);
my @dupl = qw(Rajesh Ram Peter);
my $seen;

my @names = grep {$_ ~~ @dupl ? !$seen++ : 1} @names;

print Dumper \@names;

Output:

$VAR1 = [
          'Rajesh',
          'Raju',
          'John'
        ];

The condition in grep evaluates !$seen++ if a name from @names is in @dupl, and keeps $_ only when $seen is 0. Otherwise 1 (true) is evaluated and $_ is kept.