PHP:使用类似Java的Comparable对自定义类进行排序？

class Person implements Comparable {
    private $name;
    private $age;

    public function __construct($name, $age) {
        $this->name = $name;
        $this->age = $age;
    }

    public function getName() {
        return $this->name;
    }

    public function getAge() {
        return $this->age;
    }

    public function compareTo(Person $other) {
        if ($this->age == $other->getAge()) {
            return 0;
        }
        return ($this->age < $other->getAge()) ? -1 : 1;
    }
}

$people = array(
    new Person("Alice", 30),
    new Person("Bob", 25),
    new Person("Charlie", 35)
);

usort($people, array($this, "compare"));

foreach ($people as $person) {
    echo $person->getName() . " - " . $person->getAge() . "\n";
}