Sort array by object property in PHP?

Question

If I have an object as such:

class Person {
  var $age;
  function __construct($age) {
    $this->age = $age;
  }
}

and I have any array

Answer 1

Yes. If you implement spl ArrayObject in your person object, all the normal php array functions will work properly with it.

Answer 2

For that specific scenario, you can sort it using the usort() function, where you define your own function to compare the items in the array.

<?php

class Person {
  var $age;
  function __construct($age) {
    $this->age = $age;
  }
}

function personSort( $a, $b ) {
    return $a->age == $b->age ? 0 : ( $a->age > $b->age ) ? 1 : -1;
}

$person1 = new Person(14);
$person2 = new Person(5);
$person3 = new Person(32);
$person4 = new Person(150);
$person5 = new Person(39);
$people = array($person1, $person2, $person3, $person4, $person5);

print_r( $people );

usort( $people, 'personSort' );

print_r( $people );

Answer 3

Try usort: http://www.php.net/manual/en/function.usort.php

Example:

<?php
function cmp($obja, $objb)
{
    $a = $obja->sortField;
    $b = $objb->sortField;
    if ($a == $b) {
        return 0;
    }
    return ($a < $b) ? -1 : 1;
}

$a = array( /* your objects */ );

usort($a, "cmp");

?>