如何从 json_encode 中获取数据？如何使用 AJAX 获取响应？

Question

I want to get use and its status in php from this json_encode response.How do I get it? Request Like json_encode(array('online' => $status))

  {"online":[{"user":"1004","status":"Unmonitored"},
  {"user":"1005","status":"Unmonitored"},
  {"user":"1006","status":"Unmonitored"},
  {"user":"2501","status":"Unmonitored"},
  {"user":"2502","status":"Unmonitored"},
  {"user":"2503","status":"Unmonitored"},
  {"user":"2504","status":"Unmonitored"}]}

Answer 1

You can decode JSON using the json_decode() function like so:

<?php
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
(json_decode($json);    
?>

Another Example (read a specific object):

<?php
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
$obj = json_decode($json); //read a specific object
print $obj->{'a'}; // 1
?>

UPDATE I see you updated your question to 'How to get response by using AJAX?'

          //start ajax request
            $.ajax({
                url: "data.json",
                success: function(data) {
                    //data downloaded so we call parseJSON function 
                    //and pass downloaded data
                    var json = $.parseJSON(data);
                        //do what you want to do here

                }
            });

Answer 2

PHP 5.4 offers the JSON_PRETTY_PRINT option for use with the json_encode() call.

http://php.net/manual/en/function.json-encode.php

<?php


$json_string = json_encode($data, JSON_PRETTY_PRINT);

?>

Answer 3

Seems json_decode is the function you are looking for.

<?php
$data = '{"online":[
    {"user":"1004","status":"Unmonitored"},
    {"user":"1005","status":"Unmonitored"},
    {"user":"1006","status":"Unmonitored"},
    {"user":"2501","status":"Unmonitored"},
    {"user":"2502","status":"Unmonitored"},
    {"user":"2503","status":"Unmonitored"},
    {"user":"2504","status":"Unmonitored"}
]}';

// json_decode produces stdClass object
$decoded_std = json_decode($data);
var_dump($decoded_std->online[0]->status); // "Unmonitored"

// json_decode produces associative array
$decoded_array = json_decode($data, true); // note the second param
var_dump($decoded_array['online'][0]['status']); // "Unmonitored"

Check the hosted working example here http://ideone.com/xaCx4E .