Question

I have the following piece of code:

$item_list = array();
$item_list['PENCIL']   = "Utility used to write.";
$item_list['CAR']      = "A means of transportation.";

function item_exists($name) {
    global $item_list;

    return isset($item_list[$name]);
}

function get_item_description($name) {
    global $item_list;

    return ( item_exists($name) ? $item_list[$name] : "Unknown item." );
}

On top of the file an array is defined which contains a list of items with descriptions, which are used by multiple functions. The array is never modified in the functions, it is only used as read-only data. If I want to rewrite this piece of code to avoid using global variables, what is the nicest way to do this?

Answer 1

You can encapsulate your data in a class. This is especially appropriate if you are planning to do other operations with the $item_list.

Something along these lines should get you started:

<?php
class Items
{
    private $item_list = array(
        'PENCIL' => "Utility used to write.",
        'CAR'    => "A means of transportation."
    );

    private function exists($name) {
        return isset( $this->item_list[$name]);
    }

    public function __get($name) {
        return ( $this->exists($name) ? $this->item_list[$name] : "Unknown item." );
    }

    public function __set( $key, $value) {
        $this->item_list[ $key ] = $value;
    }
}

$items = new Items;
echo $items->PENCIL . "\n"; // __get() will be called to retrieve this element's value
echo $items->IDUNNO . "\n";
$items->IDUNNO = "Not an unknown item.";
echo $items->IDUNNO . "\n";

Try it out