DB<24> $h{length}=3
 => 3

  DB<25> \%h
 => { length => 3 }

##</code><code>##

  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 }

##</code><code>##

  DB<39> $h{length $_}= 'best'
 => "best"

  DB<40> \%h
 => { 3 => 42, 4 => "best", length => 3 }