c:\@Work\Perl>perl -wMstrict -le
"confuse_the_issue(my $x, my %hash);
 ;;
 sub confuse_the_issue {
   print qq{x: $x};
   for $x (keys %hash) {
     print qq{$x $hash{$x}};
     }
   }
"
Use of uninitialized value $x in concatenation (.) or string at -e line 1.
x:

c:\@Work\Perl>perl -wMstrict -le
"sub confuse_the_issue {
   print qq{x: $x};
   for $x (keys %hash) {
     print qq{$x $hash{$x}};
     }
   }
 ;;
 confuse_the_issue(my $x, my %hash);
"
Global symbol "$x" requires explicit package name at -e line 1.
Global symbol "$x" requires explicit package name at -e line 1.
Global symbol "%hash" requires explicit package name at -e line 1.
Global symbol "$x" requires explicit package name at -e line 1.
Global symbol "%hash" requires explicit package name at -e line 1.
Global symbol "$x" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.