来自带有 json_encode 的 Php 数组的 (GET) Ajax 结果没有输出

如何解决来自带有 json_encode 的 Php 数组的 (GET) Ajax 结果没有输出

我有一个 GET 表单，它获取一个 PHP 数组，然后 json 对其进行编码。我遇到的问题是未显示成功数据。我希望成功在警报或控制台中显示数据，但由于某种原因它不起作用。我尝试了很多选择。感谢您的帮助。

PS：我知道 GET 和所有文件都可以工作，因为当我获得脚本时，Ajax 响应结果将成功填充/附加表。我正在修改它。

这是带有 AJAX 的 PHP 索引文件：

<!doctype html>
<html>
<head>
    <title>Return JSON response from AJAX using jQuery and PHP</title>
    <link href="style.css" type="text/css" rel="stylesheet">
    <script src="jquery-3.1.1.min.js" type="text/javascript"></script>
</head>
<body>
        
<script>        
 $(document).ready(function() {
    $.ajax({
        url: 'ajaxfile.PHP',type: 'get',dataType: 'JSON',success: function(data) {
            var obj = jQuery.parseJSON(data);
            alert(obj.username);
        }
    });
});
</script>  
</body>
</html>

这里是查询数据库和编码/数组json的PHP 文件：

<?PHP

$return_arr = array();

$sql = "SELECT * FROM users  ORDER BY NAME";
$result = $conn->query($sql);


// Check database connection first
if ($conn->query($sql) === FALSE) {
    echo 'database connection Failed';
    die();
} else {
    while($row = $result->fetch_array()) {
        $id = $row['id'];
        $username = $row['username'];
        $name = $row['name'];
        $email = $row['email'];
  
        $return_arr[] = array("id" => $id,"username" => $username,"name" => $name,"email" => $email);
    }
    
    // Encoding array in JSON format
    echo json_encode($return_arr);
}
?>

从PHP 文件输出的echo json_encode数组如下（测试内容）：

[{"id":"1","username":"jiten","name":"Jiten singh\t","email":"jiten9"},{"id":"2","username":"kuldeep","name":"Kuldeep","email":"kuldee"},{"id":"3","username":"mayank","name":"Mayank","email":"mayank"},{"id":"9","username":"mohit","name":"Mohit","email":"mohit"},{"id":"13","username":"mukesh","name":"Mukesh","email":"mukesh"},{"id":"6","username":"nitin","name":"Nitin","email":"niti"},{"id":"12","username":"palash","name":"Palash","email":"palash"},{"id":"7","username":"rahul","name":"Rahul singh","email":"rahul"},{"id":"10","username":"rohit","name":"Rohit singh","email":"rohit"},{"id":"8","username":"shreya","name":"Shreya","email":"shreyam"},{"id":"11","username":"sonarika","name":"Sonarika","email":"sonarika"},{"id":"5","username":"vijay","name":"Vijay","email":"vijayec"},{"id":"14","username":"vishal","name":"Vishal Sahu\t","email":"visha"},{"id":"4","username":"yssyogesh","name":"Yogesh singh","email":"yoges"}]

when I make the success result (data) and alert(data),this is what I get,empty objects

解决方法

成功后尝试迭代对象数组：函数

    $(document).ready(function () {
        $.ajax({
            url: 'ajaxfile.php',type: 'get',dataType: 'JSON',success: function (data) {
                var results = JSON.parse(data);
                let output = "";
                $.each(results,function (key,value) {
                    output += value.id + " " + value.username + " " + value.name + " " + value.email;
                });

                alert(output);
            }
        });
    });

我发现该解决方案经过测试且有效。要在 Ajax 中回显/警报 Json_encoded php 数组，您需要在警报括号内添加“JSON.stringify(data)”，如下所示。

<script>        
 $(document).ready(function(){
    $.ajax({
        url: 'ajaxfile.php',success: function(data){
         alert(JSON.stringify(data));
          

        }
    });
});

</script>