Hi lakshmikant,

Tip #4 from the Basic debugging checklist: Print your values using Data::Dumper to see what they really contain.

use Data::Dumper;
my @numbers = (15,5,7,3,9,1,20,13,9,8,15,16,2,6,12,90);
my @a = join ("," ,(sort {$a <=> $b} @numbers));
print Dumper(\@a);

__END__

$VAR1 = [ '1,2,3,5,6,7,8,9,9,12,13,15,15,16,20,90' ];
[download]

It looks a little misleading, but the quotes tell you: @a is an array with a single element, a string which contains your numbers joined by commas.

Tip: Don't join your array except for printing, e.g.

my @numbers = (15,5,7,3,9,1,20,13,9,8,15,16,2,6,12,90);
my @a = sort {$a <=> $b} @numbers;
print join(",",@a), "\n";
print $a[-2], "\n";

__END__

1,2,3,5,6,7,8,9,9,12,13,15,15,16,20,90
20
[download]

Also, note that $a[-2] gets the second-to-last element; you can get the last one via $a[-1], or even $a[$#a], since $#a gives you the last index of the array @a. (Update: ww demonstrated it here)

Hope this helps,
-- Hauke D