The reason could be:

use strict;
use warnings;
main();
xyz();
sub main{
    my $h;
    foreach (1..20){
    $h->{$_} = int rand (100);
    }
    foreach (sort by_val keys %{$h}){
    print "$_","\t",$h->{$_};
    }
}
sub xyz {
    my $k;
    foreach (1..20){
    $k->{$_} = int rand (100);
    }
    foreach (sort by_val keys %{$k}){
    print "$_","\t",$k->{$_};
    }

}
    

sub by_val {
    $h->{$a} <=> $h->{$b};
}
[download]

artist

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.