Can I add a PHP array key without an assigned value in a class variable?

Question

I am currently plowing my way through IBM's tutorial on CakePHP

At one point I run into this snippet of code:

<?php
class Dealer extends AppModel {
    var $name = 'Dealer';
    var $hasMany = array (
        'Product' => array(
            'className' => 'Product',
            'conditions'=>, // is this allowed?
            'order'=>, // same thing here
            'foreignKey'=>'dealer_id'
        )
    );
}
?>

When I run it I get the following error-message: "Parse error: syntax error, unexpected ',' in /Applications/MAMP/htdocs/cakephp/app/models/product.php on line 7"

I'm a n00b at PHP so my question is: is it allowed to make an array with keys without assigned values? Has anybody played around with this tut and know what is up?

Answer 1

Assign the value null instead of leaving anything out. The manual says

isset() will return FALSE if testing a variable that has been set to NULL

<?php
    class Dealer extends AppModel
    {
        var $name = 'Dealer';
        var $hasMany = array(
            'Product' => array(
                'className' => 'Product',
                'conditions' => null,
                'order' => null,
                'foreignKey' => 'dealer_id'
            )
        );
    }
?>

This works fine.