PHP fatal error 帮助

Question

我收到以下错误。

Fatal error: Cannot increment/decrement overloaded objects nor string offsets

这是代码。

$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"SELECT id, label, link_url, parent_id FROM dyn_menu ORDER BY parent_id, id ASC");

if (!$dbc) {
    // There was an error...do something about it here...
    print mysqli_error();
}

while ($obj = mysqli_fetch_assoc($dbc)) {
    if (!empty($obj['parent_id']) == 0) {
        echo $parent_menu . $obj['id']['label'] = $obj['label'];
        echo $parent_menu . $obj['id']['link'] = $obj['link_url'];
    } else {
        echo $sub_menu . $obj['id']['parent'] = $obj['parent_id'];
        echo $sub_menu . $obj['id']['label'] = $obj['label'];
        echo $sub_menu . $obj['id']['link'] = $obj['link_url'];
        echo $parent_menu . $obj['parent_id']['count']++;
    }
}
mysql_free_result($dbc);

Answer 1

您的 $obj['parent_id'] 是一个字符串(包含数字，例如 "0") - 它不是一个带有 count< 的数组 条目。这会更有意义:

$obj['parent_id']++

另外，这非常令人困惑:

if (!empty($obj['parent_id']) == 0) {

这会更有意义:

if (empty($obj['parent_id'])) {