PHP：compareTo类似于Java

Question

In an effort to utilize OOP in PHP, I was looking for a way to define functions within objects to use for sorting. in Java this is simple, as the compareTo() is automatically called by sorted arrays and such. I looked around PHP.net and couldn't find anything similar in PHP. I have resorted to what seems like a hack to me, so I'm wondering if anyone can lend some insight on an easier way.

CURRENT CODE:

class SomeObject {
    private $someField;

    function getSomeField() { return $this->someField; }

    function compareTo($other) {
        return $this->someField - $other->getSomeField();
    }
}

//in funcs.php
function objSort($a, $b) {
    return $a->compareTo($b);
}


//To sort an array
usort($array, objSort);

Is there an easier/more sleek way of doing this in PHP?

Answer 1

You could use anonymous function directly.

class SomeObject {
    private $someField;
    function getSomeField() { return $this->someField; }
}

usort($array, function($a, $b) {
    return $a->getSomeField() - $b->getSomeField();
});

Or you could define a static function use to compare.

class SomeObject {
    private $someField;

    function getSomeField() { return $this->someField; }

    static function compare($a, $b) {
        return $a->getSomeField() - $b->getSomeField();
    }
}

usort($array, array('SomeObject', 'compare'));