Check and set array to null - php

Question

I am trying to set result_array to null if there are no existing data in the database. The result should be shown in a table format but I cannot get the result_array as null and keep getting error on the line $result_array[] = null;
global $db;
$db = new mysqli();
$db->connect("localhost", "root", "", "databasename");
$db->set_charset("utf8");
if ($db->connect_errno) {
printf("Connection has failed: %s\n", $db->connect_error);
exit();
}
$html = '';
$html .= '<li class="result">';
$html .= '<a target="_blank" href="url">';
$html .= '<h3>name</h3>';
$html .= '</a>';
$html .= '</li>';
$search = preg_replace("/[^A-Za-z0-9]/", " ", $_POST['query']);
$search = $db->real_escape_string($search);
if (strlen($search) >= 1 && $search !== ' ') {
$query = 'SELECT * FROM tablename WHERE name LIKE "%'.$search.'%"';
$result = $db->query($query) or trigger_error($db->error."[$query]");
if(!$results = $result->fetch_array()){
$resultArray[] = null;
}
else{
while($results = $result->fetch_array()) {
$resultArray[] = $results;
}
}
if (isset($resultArray)) {
foreach ($resultArray as $result) {
$show_name = preg_replace("/".$search."/i", "<b class='highlight'>".$search."</b>", $result['name']);
$show_url = 'index.php';
$out = str_replace('name', $show_name, $html);
$out = str_replace('url', $show_url, $out);
$_SESSION['result']= $result['name'];
echo($out);
}
}else{
$out = str_replace('url', 'javascript:void(0);', $html);
$out = str_replace('name', '<b>No Results.</b>', $out);
echo($out);
}
}
?>

Answer 1

why aren't you using this?
...
$result_array = array();
if(!$results = $result->fetch_array()){
//do nothing
}
else{
while($results = $result->fetch_array()) {
$result_array[] = $results;
}
...
Also please use either $result_array or $resultArray