DB<33> $_="abc"
 => "abc"

  DB<34> $h{length()}=42
 => 42

  DB<35> \%h
 => { 3 => 42, length => 3 }

  DB<36> $_="abcd"
 => "abcd"

  DB<37> $h{(length)}=666
 => 666

  DB<38> \%h
 => { 3 => 42, 4 => 666, length => 3 }