Hi!
Usually, arrays are used when you don't know in advance how many items you are going to deal with. Of course, it is easy enough to create variable variables for this purpose, but they trash up your code and are not suitable when you want to deal with items in a similar way.
Arrays resemble a table in a way, to can add rows and columns to this 'table' by adding an array to the array:
$table = array(array("Microsoft", "Redmond, VA"), array("Borland", "Hell if I know"));
In this case, you will refer to each 'row' with a number starting from 0.
print_r($table[0]);
You can also use powerful associative arrays where you add an item using a key that can be used later on for looking up the data you've added:
$table = array("microsoft"=>array("name"=>"Microsoft", "address"=>Redmond, VA"));
Arrays can be used as stacks. Stacks are especially useful to maintain history of changes.
$history = array();
array_push($history, array("10:30", "Messed up the house badly"));
array_push($history, array("11:30", "Man, I need to undo the whole thing, this is a mess!");
If you are maintaing the history of changes as a set of objects with properties specifying what exactly you did, it would be easy enough for you to 'undo' what you did. This is used in Editors mainly.
If you are printing records from a database, you will find arrays very useful since you can get a row as an associative array where the key of the items are the name of fields in the database.
$row = mysql_fetch_array($result, MYSQL_ASSOC);
Usually, use arrays whenever you need to store information is a more understandable and clear way.
Hope this comes in useful,
Stas
