How do I adapt/utilize array_unique() to handle objects?

Question

I have objects such as these:

class Log
{
    public matches;

    public function __construct()
    {
        $this->matches = array();
    }
}

class Match
{
    public owner;
    public stuff;
}

Throughout my program, I store data into $owner and $stuff and access it via iterating through the array matches for the Log object. What I am wondering is how to get an array containing a list of all the unique owners.

For example, if I have the following information:

Bill SomeStuff
Bob SomeOtherStuff
Stan MoreOtherStuff
Bill MoreOfBillsStuff
Bill BillhasLotsofStuff

How do I go about getting an array that contains merely Bill, Bob, Stan?

Answer 1

This is an example function that you could add to the Log class to return a list of owners:

function getOwners()
{
    $owners = array();
    foreach($this->matches as $match)
    {
        $owners[$match->owner] = 0;
    }

    return array_keys($owners);
}