The quick way to remember this is that hashes naturally consume and supply lists.  When a hash consumes a list, it alternates to assigning list items as keys and values.  When a hash is supplied on the right hand side of an assignment, it&#x27;s keys and values are supplies as a list in alternating order.  <i>Values</i> for a hash or array must be a regular variable (scalar), or a <i>reference</i> to some item (such as an object, hash, array or scalar).