use strict;
use warnings;

my @old = qw(one two three);
my @new = qw(one foo two bar three baz);

print '@old array' . "\n";
print "$_\n" for (@old);

print "\n" . '@new array' . "\n";
print "$_\n" for (@new), "\n";

foreach my $element (@new) {
    if ( $element ~~ @old ) {
        print "matched $element";
    }
    else {
        print "\ndidnt match $element...Adding $element to old array\n";
        push( @old, $element );
    }
}
print "\n" . '@old array' . "\n";
print "$_\n" for (@old);