Say I have an array $order containing the data of entire order and user as well.
To display the name of user; I use $order['users'][33]['firstname'];. I do this in several parts of page.
Does it really matter to the memory and process to do this way (using associative array)? Or should I store user in a variable
$user = $order['users'][33]['firstname'];
and keep using $user where ever needed? Which method is prefered?
It really depends on what your application does. If $order contains only one user and every subarray contain only one data value, then store the information in variables and give them readable names. Otherwise, if $order contains many users and information are kind of a tree, then array is definitely a good way to implement your application. In terms of memory consumption, as long as you are storing the same amount of information I don't think it will be a crucial difference.