ajax json 响应解析错误和语法错误答案

【问题标题】：ajax json response parseerror & syntaxerrorajax json 响应解析错误和语法错误
【发布时间】：2018-10-16 05:33:37
【问题描述】：

我有一些返回 JSON 数据类型响应的 AJAX 函数。但是，服务器似乎有一些限制，并且我在本地运行脚本时没有错误。

AJAX 代码：

$.ajax({
  url: 'alterajax.php',
  method: 'POST',
  data: {value},
  dataType:'json',
  success: function(data){
    //at the moment for testing
    console.log(data)
  }
});

PHP：

$alterquery = $connection->prepare("SELECT tracking_type, tracking_change_date, tracking_effective_date, IFNULL(vessel_fcm_new, ''), IFNULL(vessel_fcm_old, ''), IFNULL(vessel_hull_id_new, ''), IFNULL(vessel_hull_id_old, ''), IFNULL(vessel_flag_new, ''), IFNULL(vessel_flag_old, ''), IFNULL(vessel_name_new, ''), IFNULL(vessel_name_old, ''), IFNULL(vessel_length_new, ''), IFNULL(vessel_length_old, ''), IFNULL(vessel_manufacturer_new, ''), IFNULL(vessel_manufacturer_old, ''), IFNULL(vessel_manufacturer_id_new, ''), IFNULL(vessel_manufacturer_id_old, ''), IFNULL(vessel_year_new, ''), IFNULL(vessel_year_old, ''), IFNULL(vessel_value_new, ''), IFNULL(vessel_value_old, ''), IFNULL(owner_id_new, ''), IFNULL(owner_id_old, ''), IFNULL(owner_street_new, ''), IFNULL(owner_street_old, ''), IFNULL(owner_city_new, ''), IFNULL(owner_city_old, ''), IFNULL(owner_state_new, ''), IFNULL(owner_state_old, ''), IFNULL(owner_zip_new, ''), IFNULL(owner_zip_old, ''), IFNULL(owner_country_new, ''), IFNULL(owner_country_old, ''), IFNULL(loss_payee_id_new, ''), IFNULL(loss_payee_id_old, ''), IFNULL(loss_payee_street_new, ''), IFNULL(loss_payee_street_old, ''), IFNULL(loss_payee_city_new, ''), IFNULL(loss_payee_city_old, ''), IFNULL(loss_payee_state_new, ''), IFNULL(loss_payee_state_old, ''), IFNULL(loss_payee_zip_new, ''), IFNULL(loss_payee_zip_old, ''), IFNULL(base_id_new, ''), IFNULL(base_id_old, ''), IFNULL(policy_id_new, ''), IFNULL(policy_id_old, ''), IFNULL(policy_start_date_new, ''), IFNULL(policy_start_date_old, ''), IFNULL(policy_end_date_new, ''), IFNULL(policy_end_date_old, ''), IFNULL(vessel_fcm, ''), IFNULL(vessel_hull_id, ''), IFNULL(vessel_name, ''), IFNULL(vessel_manufacturer_id, '') FROM tracking WHERE tracking_type = ? ORDER BY tracking_change_date DESC LIMIT 20");
$alterquery->bind_param("i", $trackingtype);
$trackingtype = 333;
$alterquery->execute();
$alterquery->bind_result($tracking_type, $tracking_change_date, $tracking_effective_date, $vessel_fcm_new, $vessel_fcm_old, $vessel_hull_id_new, $vessel_hull_id_old, $vessel_flag_new, $vessel_flag_old, $vessel_name_new, $vessel_name_old, $vessel_length_new, $vessel_length_old, $vessel_manufacturer_new, $vessel_manufacturer_old, $vessel_manufacturer_id_new, $vessel_manufacturer_id_old, $vessel_year_new, $vessel_year_old, $vessel_value_new, $vessel_value_old, $owner_id_new, $owner_id_old, $owner_street_new, $owner_street_old, $owner_city_new, $owner_city_old, $owner_state_new, $owner_state_old, $owner_zip_new, $owner_zip_old, $owner_country_new, $owner_country_old, $loss_payee_id_new, $loss_payee_id_old, $loss_payee_street_new, $loss_payee_street_old, $loss_payee_city_new, $loss_payee_city_old, $loss_payee_state_new, $loss_payee_state_old, $loss_payee_zip_new, $loss_payee_zip_old, $base_id_new, $base_id_old, $policy_id_new, $policy_id_old, $policy_start_date_new, $policy_start_date_old, $policy_end_date_new, $policy_end_date_old, $vessel_fcm, $vessel_hull_id, $vessel_name, $vessel_manufacturer_id);
while ($alterquery->fetch()){
    $data[] = array($tracking_type, $tracking_change_date, $tracking_effective_date, $vessel_fcm_new, $vessel_fcm_old, $vessel_hull_id_new, $vessel_hull_id_old, $vessel_flag_new, $vessel_flag_old, $vessel_name_new, $vessel_name_old, $vessel_length_new, $vessel_length_old, $vessel_manufacturer_new, $vessel_manufacturer_old, $vessel_manufacturer_id_new, $vessel_manufacturer_id_old, $vessel_year_new, $vessel_year_old, $vessel_value_new, $vessel_value_old, $owner_id_new, $owner_id_old, $owner_street_new, $owner_street_old, $owner_city_new, $owner_city_old, $owner_state_new, $owner_state_old, $owner_zip_new, $owner_zip_old, $owner_country_new, $owner_country_old, $loss_payee_id_new, $loss_payee_id_old, $loss_payee_street_new, $loss_payee_street_old, $loss_payee_city_new, $loss_payee_city_old, $loss_payee_state_new, $loss_payee_state_old, $loss_payee_zip_new, $loss_payee_zip_old, $base_id_new, $base_id_old, $policy_id_new, $policy_id_old, $policy_start_date_new, $policy_start_date_old, $policy_end_date_new, $policy_end_date_old, $vessel_fcm, $vessel_hull_id, $vessel_name, $vessel_manufacturer_id);
}
echo json_encode($data);
?>

错误：

状态：解析器错误
错误：SyntaxError：JSON 输入意外结束
错误：SyntaxError：JSON.parse 错误：位置意外输入：0

不确定是什么原因造成的。我还有 2 个与此非常相似的其他 ajax 调用（只是从不同的表中选择，但数据不多，它们以 JSON 格式返回）

【问题讨论】：

您的结束标签?> 后面是否有一些空格？您可以尝试删除它吗，因为它在仅 php 的文件中是可选的。
@Sean 没用
你返回的 json 是什么样的？可以直接访问php代码页看看输出是什么吗？
这是 Godaddy 服务器吗？尝试在 echo 之前添加 header('Content-type: application/json');
在 while 循环之前添加 $data = [];。我认为这不是问题，但这只是一种好习惯

标签： php json ajax

【解决方案1】：

在while循环之后，解决了收不到数据的问题。

function utf8_converter($array)
{
    array_walk_recursive($array, function(&$item, $key){
        if(!mb_detect_encoding($item, 'utf-8', true)){
                $item = utf8_encode($item);
        }
    });

    return $array;
}

echo json_encode(utf8_converter($data));

服务器是否设置为特定编码（utf-8）？

【讨论】：