javascript - How does php return a json object when responding to ajax? Am I doing this right?

Is this how to echo json string?

<code>function my()
{
    ...
    
    echo {"code":"NO_ERROR","msg":"获取系统参数成功"}
}</code>

Reply content:

Is this how to echo json string?

<code>function my()
{
    ...
    
    echo {"code":"NO_ERROR","msg":"获取系统参数成功"}
}</code>

<code>$.ajax({
    type: "GET",
    url: "http://www.example.com/json.php",
    data: {name:"ele", pass:"123"}, //这里的data是参数,跟下面回调函数里服务器返回的data不是一个东西
    success: function(data){ console.log(data); }
});
<?php
$arr = array(
    'code' => 'NO_ERROR',
    'msg' => '获取系统参数成功',
);
header('Content-Type: application/json; charset=utf-8');
echo json_encode($arr);</code>

Although I don’t know your specific problem scenario, I will answer based on my development experience. I have encountered json returned by java calling php, but when json_encode an empty array, java cannot recognize it. At this time You need to make an additional judgment. You need to judge whether the object you pass in is empty: json_encode(array('data' => (empty($data) ? new stdclass() : $data)))

It is easy to make mistakes when writing strings yourself, such as special strings, etc. It is recommended to use json_encode($obj), a powerful php method

In fact, it is not necessary. It is too troublesome to write like this. It is usually written as an array. Then json_encode is enough

$this->ajaxReturn(json_encode($data), "JSON");