Further to 1nickt's post: pritesh_ugrankar: Note that the local scoping (or aliasing) of a for-loop iteration variable is very strong and holds even if you do not declare a separate lexical for each loop:

c:\@Work\Perl\monks\nysus>perl -wMstrict -le
"my @x = (1, 2);
 my @y = qw(foo bar);
 ;;
 my $z = 'original';
 for $z (@x) {
   printf qq{$z };
   for $z (@y) {
     printf qq{'$z' };
     }
   print $z;
   }
 print qq{after all loops: '$z'};
"
1 'foo' 'bar' 1
2 'foo' 'bar' 2
after all loops: 'original'
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(But yes, certainly use different variable names as a sanity-saver!)