How to get commen elements from multiple arrays

[Ravi More]

Hello, I want to get comment element from three arrays.

Please Help me.

Thanks in advance!

# To retrieve common elements from three array
#!/usr/bin/perl
use strict;
use warnings;
my @a1;   my @a2;    my @a3;
my @data1 = ("sajan","ravi","arvind");  # Multiple arrays
my @data2 = ("sajan","ravi","arjun");
my @data3 = ("mahesh","raj","ravi");
@a1 = sort {lc($a) cmp lc($b)} @data1;  # Sorting a to z
@a2 = sort {lc($a) cmp lc($b)} @data2;
@a3 = sort {lc($a) cmp lc($b)} @data3;

foreach my $a3 (my @a1, my @a2)          #compair @a3 array wirh @a1 & @a2
{
        if (my $a1 || my $a2 =~ my $a3)
        {
        print "Common element in all three array is: $a3";
        }
}

[RonB]

D:\perl>perldoc -q duplicate

Found in C:\Perl64\lib\pods\perlfaq4.pod
  How can I remove duplicate elements from a list or array?
    (contributed by brian d foy)

    Use a hash. When you think the words "unique" or "duplicated", think
    "hash keys".

    If you don't care about the order of the elements, you could just create
    the hash then extract the keys. It's not important how you create that
    hash: just that you use "keys" to get the unique elements.

            my %hash   = map { $_, 1 } @array;
            # or a hash slice: @hash{ @array } = ();
            # or a foreach: $hash{$_} = 1 foreach ( @array );

            my @unique = keys %hash;

    If you want to use a module, try the "uniq" function from
    "List::MoreUtils". In list context it returns the unique elements,
    preserving their order in the list. In scalar context, it returns the
    number of unique elements.

            use List::MoreUtils qw(uniq);

            my @unique = uniq( 1, 2, 3, 4, 4, 5, 6, 5, 7 ); # 1,2,3,4,5,6,7
            my $unique = uniq( 1, 2, 3, 4, 4, 5, 6, 5, 7 ); # 7

    You can also go through each element and skip the ones you've seen
    before. Use a hash to keep track. The first time the loop sees an
    element, that element has no key in %Seen. The "next" statement creates
    the key and immediately uses its value, which is "undef", so the loop
    continues to the "push" and increments the value for that key. The next
    time the loop sees that same element, its key exists in the hash *and*
    the value for that key is true (since it's not 0 or "undef"), so the
    next skips that iteration and the loop goes to the next element.

            my @unique = ();
            my %seen   = ();

            foreach my $elem ( @array )
                    {
                    next if $seen{ $elem }++;
                    push @unique, $elem;
                    }

    You can write this more briefly using a grep, which does the same thing.

            my %seen = ();
            my @unique = grep { ! $seen{ $_ }++ } @array;

[numberwhun]

The next time you post code in the forums, you need to please surround it with code tags.

Also, you should really expand upon just posting code and try telling us what is going wrong or not happening in your code. You cannot just expect us to run your code and figure it out. We would really like some kind of explanation of what you are expecting what you are seeing and what is going wrong or not happening.

Regards,

Jeff