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

$persons = array(
    new Person("peter", 10),
    new Person("jane",  14),
    new Person("allan", 42),
    new Person("lis",   23),
    new Person("jimmy", 19),
    new Person("ruth",   7)
);


// names of persons above 18 ordered alphabetically
$names = phlinq($persons)
    ->where(function($p) { return $p->age > 18; })
    ->select(function($p) { return $p->name; })
    ->order()
    ;

var_dump($names->toArray());
/*
array(3) {
  [0]=>
  string(4) "allan"
  [1]=>
  string(5) "jimmy"
  [2]=>
  string(3) "lis"
} 
*/


// same names but ordered by age (youngest first)
$names = phlinq($persons)
    ->where(function($p) { return $p->age > 18; })
    ->orderBy(function($p) { return $p->age; })
    ->select(function($p) { return $p->name; })
    ;

var_dump($names->toArray());

/*
array(3) {
  [0]=>
  string(5) "jimmy"
  [1]=>
  string(3) "lis"
  [2]=>
  string(4) "allan"
}
*/