Sorting array of objects by function in PHP - php

Question

Let's say I have an object called ACCOUNT like:
class ACCOUNT
{
private $contact;
public function getContact();
}
and another object CONTACT:
class CONTACT
{
private $lastName;
public function getLastName()
{
return $this->lastName;
}
}
Then I create an array of these objects $accountArray = ACCOUNT::get();
How can I sort this array alphabetically by something like $account->getContact()->getLastName();?
What I've tried:
class Account
{
private $contact;
public function getContact();
public static function cmp($a,$b)
{
$al = strtolower($a->getContact()->getLastName());
$bl = strtolower($b->getContact()->getLastName());
if ($al == $bl) {
return 0;
}
return ($al > $bl) ? +1 : -1;
}
public static function sortByLastName($accountArray)
{
usort($moACOUNTArray, array('ACCOUNT', 'cmp'));
}
}
But I get this error:
Call to undefined method ACCOUNT::getContact()

Answer 1

You can use usort function of PHP, like mentioned in comments. There is self-explaining example:
Try this code:
<?php
class ACCOUNT
{
private $contact;
public function getContact()
{
return $this->contact;
}
public function setContact($v)
{
$this->contact = $v;
}
}
class CONTACT
{
private $lastName;
public function getLastName()
{
return $this->lastName;
}
public function setLastName($v)
{
$this->lastName = $v;
}
}
//create data for testing
$c1 = new CONTACT;
$c1->setLastName('aaaa');
$a1 = new ACCOUNT;
$a1->setContact($c1);
$c2 = new CONTACT;
$c2->setLastName('zzz');
$a2 = new ACCOUNT;
$a2->setContact($c2);
$c3 = new CONTACT;
$c3->setLastName('ggg');
$a3 = new ACCOUNT;
$a3->setContact($c3);
$array = array($a1, $a2, $a3);
//making sort
function cmp($a, $b)
{
return strcmp($a->getContact()->getLastName(), $b->getContact()->getLastName());
}
usort($array, "cmp");
//showing sort result
echo '<pre>';
print_r($array);
Result is:
Array
(
[0] => ACCOUNT Object
(
[contact:ACCOUNT:private] => CONTACT Object
(
[lastName:CONTACT:private] => aaaa
)
)
[1] => ACCOUNT Object
(
[contact:ACCOUNT:private] => CONTACT Object
(
[lastName:CONTACT:private] => ggg
)
)
[2] => ACCOUNT Object
(
[contact:ACCOUNT:private] => CONTACT Object
(
[lastName:CONTACT:private] => zzz
)
)
)