a set of key/value pairs

Does anyone have a specific example of how to:
     1) create a variable that is a set or array of key value pairs?
     2) how to populate each element of the array (each element being a
key / value pair)
     3) how to iterate through the list or array retrieving each
key/value pair?

Please do not point me to this doc:
     http://developer.postgresql.org/pgdocs/postgres/hstore.html

What I am looking for is an example as listed in 1..3 above, and that is
not provided in the doc.

Regards,


J.V.