Sort Object in PHP

Question

What is an elegant way to sort objects in PHP? I would love to accomplish something similar to this.

$sortedObjectArary = sort($unsortedObjectArray, $Object-         


        

Answer 1

For php >= 5.3

function osort(&$array, $prop)
{
    usort($array, function($a, $b) use ($prop) {
        return $a->$prop > $b->$prop ? 1 : -1;
    }); 
}

Note that this uses Anonymous functions / closures. Might find reviewing the php docs on that useful.

Answer 2

You could use the usort() function and make your own comparison function.

$sortedObjectArray = usort($unsortedObjectArray, 'sort_by_weight');

function sort_by_weight($a, $b) {
    if ($a->weight == $b->weight) {
        return 0;
    } else if ($a->weight < $b->weight) {
        return -1;
    } else {
        return 1;
    }
}

Answer 3

You can even build the sorting behavior into the class you're sorting, if you want that level of control

class thingy
{
    public $prop1;
    public $prop2;

    static $sortKey;

    public function __construct( $prop1, $prop2 )
    {
        $this->prop1 = $prop1;
        $this->prop2 = $prop2;
    }

    public static function sorter( $a, $b )
    {
        return strcasecmp( $a->{self::$sortKey}, $b->{self::$sortKey} );
    }

    public static function sortByProp( &$collection, $prop )
    {
        self::$sortKey = $prop;
        usort( $collection, array( __CLASS__, 'sorter' ) );
    }

}

$thingies = array(
        new thingy( 'red', 'blue' )
    ,   new thingy( 'apple', 'orange' )
    ,   new thingy( 'black', 'white' )
    ,   new thingy( 'democrat', 'republican' )
);

print_r( $thingies );

thingy::sortByProp( $thingies, 'prop1' );

print_r( $thingies );

thingy::sortByProp( $thingies, 'prop2' );

print_r( $thingies );

Answer 4

Almost verbatim from the manual:

function compare_weights($a, $b) { 
    if($a->weight == $b->weight) {
        return 0;
    } 
    return ($a->weight < $b->weight) ? -1 : 1;
} 

usort($unsortedObjectArray, 'compare_weights');

If you want objects to be able to sort themselves, see example 3 here: http://php.net/usort

Answer 5

If you want to explore the full (terrifying) extent of lambda style functions in PHP, see: http://docs.php.net/manual/en/function.create-function.php

Answer 6

function PHPArrayObjectSorter($array,$sortBy,$direction='asc')
{
    $sortedArray=array();
    $tmpArray=array();
    foreach($this->$array as $obj)
    {
        $tmpArray[]=$obj->$sortBy;
    }
    if($direction=='asc'){
        asort($tmpArray);
    }else{
        arsort($tmpArray);
    }

    foreach($tmpArray as $k=>$tmp){
        $sortedArray[]=$array[$k];
    }

    return $sortedArray;

}

e.g =>

$myAscSortedArrayObject=PHPArrayObjectSorter($unsortedarray,$totalMarks,'asc');

$myDescSortedArrayObject=PHPArrayObjectSorter($unsortedarray,$totalMarks,'desc');