Евгений

$GLOBALS['arrFilter'] = ['PROPERTY_CITY_INFO' => $_POST['id']];

$GLOBALS['arrFilter'] = ['=PROPERTY_CITY_INFO.NAME' => 'Москва'];

Array ( 
	[data] => Array (
		[ActionsResult] => Array ( )
		[Accounts] => Array (
			[0] => Array ( 
				[Login] => pl4tpass 
				[Discount] => 0 
				[Currency] => RUB 
				[AmountAvailableForTransfer] => 0 
				[SmsNotification] => Array ( 
					[MoneyOutSms] => No
					[PausedByDayBudgetSms] => Yes
					[SmsTimeTo] => 21:00
					[MoneyInSms] => No
					[SmsTimeFrom] => 09:00 
				)
				[Amount] => 0 
				[AgencyName] => 
				[EmailNotification] => Array (
					[SendWarn] =>
					[MoneyWarningValue] => 20
					[PausedByDayBudget] => Yes
					[Email] => pl4tpass@yandex.ru
				) 
				[AccountID] => 49797112 
			) 
		) 
	) 
)

$tov = mysql_query("SELECT product_id FROM oc_product_to_category WHERE category_id = $cat_id", $link);
while ($result = mysql_fetch_array($tov)) {
	$productId[] = $result['product_id'];
}

$searchIn = implode(',', $productId);

$sel = mysql_query("SELECT `seller_id` FROM `oc_ms_product` WHERE product_id IN ($searchIn)" , $link);
while ($resul = mysql_fetch_array($sel)) {
	echo $resul['seller_id'] . '<br>';
}

$string = 'id=171:znac=1;id=203:znac=1;id=225:znac=1;id=162:znac=0.5;id=203:znac=31;';

preg_match_all('/id=(\d+)/', $string, $matches);

var_dump($matches[1]);

$string = '[17650,17776,17777]';

preg_match_all('/\d+/', $string, $matches);

var_dump($matches[0]);

$data = [
	341 => [
		'name_rm' => 'Мастер',
		'type_id' => 4,
		'contract_id' => 6,
		'equipment' => 'CyberPower BE700ELCD',
		'serial_number' => '1GS7W3002242'
	],
	342 => [
		'name_rm' => 'Мастер',
		'type_id' => 4,
		'contract_id' => 6,
		'equipment' => 'CyberPower BE700ELCD',
		'serial_number' => '1GS7W3002242'
	],
	343 => [
		'name_rm' => 'Мастер',
		'type_id' => 4,
		'contract_id' => 6,
		'equipment' => 'CyberPower BE700ELCD',
		'serial_number' => '1GS7W3002242'
	]
];

$array = array_column($data, 'contract_id');
$array = array_unique($array);

if(count($array) > 1) {
	echo 'Ошибка'; 
}
elseif($array[0]) {
	echo $array[0];
}

public function buildTree($data) {

    $childs = array();

    foreach($data as &$item) {
         $childs[$item['parent_id']][] = &$item;
         unset($item);
    }

    foreach($data as &$item) {
        if (isset($childs[$item['id']])) {
            $item['childs'] = $childs[$item['id']];
        }
    }
    return $childs[0];
}