You're doing captures for nothing. Fix:

my $suffix;
$suffix = 'st' if ($nouser =~ /1$/);
$suffix = 'nd' if ($nouser =~ /2$/);
$suffix = 'rd' if ($nouser =~ /3$/);
$suffix = 'th' if ($nouser =~ /(?:4|5|6|7|8|9|0)$/);
$suffix = 'th' if ($nouser =~ /(?:11|12|13)$/);

[download]

You're executing every regexp for nothing. Fix:

my $suffix;
if    ($nouser =~ /(?<!1)1$/) { $suffix = 'st'; }
elsif ($nouser =~ /(?<!1)2$/) { $suffix = 'nd'; }
elsif ($nouser =~ /(?<!1)3$/) { $suffix = 'rd'; }
else                          { $suffix = 'th'; }

[download]

Alternative styles:

my $suffix;
local *_ = \$nouser;
if    (/(?<!1)1$/) { $suffix = 'st'; }
elsif (/(?<!1)2$/) { $suffix = 'nd'; }
elsif (/(?<!1)3$/) { $suffix = 'rd'; }
else               { $suffix = 'th'; }

[download]
my $suffix;
foreach ($nouser) {
   if    (/(?<!1)1$/) { $suffix = 'st'; }
   elsif (/(?<!1)2$/) { $suffix = 'nd'; }
   elsif (/(?<!1)3$/) { $suffix = 'rd'; }
   else               { $suffix = 'th'; }
}

[download]
my $suffix;
foreach ($nouser) {
   /(?<!1)1$/ && do { $suffix = 'st';  last };
   /(?<!1)2$/ && do { $suffix = 'nd';  last };
   /(?<!1)3$/ && do { $suffix = 'rd';  last };

   $suffix = 'th';
}

[download]

In reply to Re^2: adding st,nd,rd and th to numbers by ikegami
in thread adding st,nd,rd and th to numbers by anniyan

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