Associative arrays

[Jawelin]

Hi. Where could I find an exaustive help with examples about multi-dimensional arrays ?
Actually I would - for a hack - store in memory some fields of a table of VB (user), to make some intensive operation without loading the db.
I thought a 2D array like this: $userArray[][]
Would use the two index, first as userid or other incremental value, second as the fields in the table.
For instance:

$userArray[][name]=$user[username]
$userArray[][mail]=$user[email]
... etc. in a cycle after a db fetch, but of course it doesn't work this way...
Neither with an explicit first index as variable.

Do you have some example to load table in array with more values than the (key,value) as in php.net ?

Thanks a lot.
Bye