Null Coalescing Operator Chains in PHP

Coalescing operators can be called one after another in a chain. In the following example, the variable will be assigned either the first element of the array, or the second element of the array, or a given string, if these elements do not exist:

<?php
	$elem = $arr['test1'] ?? $arr['test2'] ?? 'empty';
?>

Rewrite the following code using the studied operator:

<?php
	if (isset($user['name'])) {
		$res = $user['name'];
	} elseif (isset($user['surname'])) {
		$res = $user['surname'];
	} else {
		$res = '';
	}
?>