my $foo = "foo's $bar";
          ^
##</code><code>##

my $foo = "foo's $bar";
          ^---------->
##</code><code>##

  <perlcode>
    <reserved>my</reserved>
    <variable>$foo</variable>
    <operator>=</operator>
    <string>"foo's <variable>$bar</variable>"</string>;
  </perlcode>