c:\@Work\Perl\monks>perl -wMstrict -le
"use Data::Dump qw(dd);
 ;;
 my ($name1, $name3, $name5, $name7, $name9, $name11) =
   qw(Bill Jill Phil Will Gill Al);
 my @student = (\$name1, \$name3, \$name5, \$name7, \$name9, \$name11);
 ;;
 my ($age1, $age2, $age3, $age4, $age5, $age6) =
   (11, 22, 33, 44, 55, 66);
 my @all = (\$age1, \$age2, \$age3, \$age4, \$age5, \$age6);
 ;;
 dd \@student;
 dd \@all;
 ;;
 for (my $i = 0;  $i < @student;  ++$i) {
   if (${ $student[$i] } eq 'Al') {
     ${ $all[$i] } = ${ $all[$i] } * 11;
     }
   elsif (${ $student[$i] } eq 'Phil') {
     ${ $all[$i] } = ${ $all[$i] } * 111;
     }
   else {
     print qq{no satisfying condition for index $i};
     }
   }
 ;;
 dd \@all;
"
[\"Bill", \"Jill", \"Phil", \"Will", \"Gill", \"Al"]

[\11, \22, \33, \44, \55, \66]

no satisfying condition for index 0
no satisfying condition for index 1
no satisfying condition for index 3
no satisfying condition for index 4
[\11, \22, \3663, \44, \55, \726]

##</code><code>##

for my $i (0 .. $#student) {
  if (${ $student[$i] } eq 'Al') {
    ...
    }
  ...
  }