我有这个错误
致命错误：在128行调用未定义的方法RecursiveArrayIterator :: fetch_array（）
$hierachy = new hierachy;
$iterator = new RecursiveIteratorIterator(new recursiveArrayIterator($hierachy->getSamelevelNode($name1)));
try {
while($row = $iterator->fetch_array()) { //line where error is coming from 128
if(!isset($targ)) {
$targ = $row['left_node']+1;
}
if($row['left_node'] == $targ) {
echo $row['name'];
$targ = $row['right_node']+1;
}
}