$x = ~ /regex/;
%hash = map { "\L$_", 1 } @array;

##</code><code>##

$hash1 = { a => 1 };
$hash1{b} = 2;
# $hash1{a} == 1, right?  No?

##</code><code>##

foreach (@foo_list) {
    my $x = "blah $_ blah";
    my $foo = $_;
    while ( something() ) {
        # more stuff
        foreach (@bar_list) {
            other( $_ );
        }
    }
    more_with( $foo );
}