我使用json_decode()得到一个奇怪的错误。它正确解码数据(我看到它使用print_r),但当我试图访问数组内的信息时,我得到:

Fatal error: Cannot use object of type stdClass as array in
C:\Users\Dail\software\abs.php on line 108

我只想做:$result['context']其中$result有json_decode()返回的数据

如何读取这个数组中的值?


当前回答

不要使用括号,而是使用对象操作符,例如,我的基于数据库对象的数组是在一个名为DB的类中创建的:

class DB {
private static $_instance = null;
private $_pdo,
        $_query, 
        $_error = false,
        $_results,
        $_count = 0;



private function __construct() {
    try{
        $this->_pdo = new PDO('mysql:host=' . Config::get('mysql/host') .';dbname=' . Config::get('mysql/db') , Config::get('mysql/username') ,Config::get('mysql/password') );


    } catch(PDOException $e) {
        $this->_error = true;
        $newsMessage = 'Sorry.  Database is off line';
        $pagetitle = 'Teknikal Tim - Database Error';
        $pagedescription = 'Teknikal Tim Database Error page';
        include_once 'dbdown.html.php';
        exit;
    }
    $headerinc = 'header.html.php';
}

public static function getInstance() {
    if(!isset(self::$_instance)) {
        self::$_instance = new DB();
    }

    return self::$_instance;

}


    public function query($sql, $params = array()) {
    $this->_error = false;
    if($this->_query = $this->_pdo->prepare($sql)) {
    $x = 1;
        if(count($params)) {
        foreach($params as $param){
            $this->_query->bindValue($x, $param);
            $x++;
            }
        }
    }
    if($this->_query->execute()) {

        $this->_results = $this->_query->fetchAll(PDO::FETCH_OBJ);
        $this->_count = $this->_query->rowCount();

    }

    else{
        $this->_error = true;
    }

    return $this;
}

public function action($action, $table, $where = array()) {
    if(count($where) ===3) {
        $operators = array('=', '>', '<', '>=', '<=');

        $field      = $where[0];
        $operator   = $where[1];
        $value      = $where[2];

        if(in_array($operator, $operators)) {
            $sql = "{$action} FROM {$table} WHERE {$field} = ?";

            if(!$this->query($sql, array($value))->error()) {
            return $this;
            }
        }

    }
    return false;
}

    public function get($table, $where) {
    return $this->action('SELECT *', $table, $where);

public function results() {
    return $this->_results;
}

public function first() {
    return $this->_results[0];
}

public function count() {
    return $this->_count;
}

}

我在控制器脚本上使用这段代码来访问信息:

<?php
$pagetitle = 'Teknikal Tim - Service Call Reservation';
$pagedescription = 'Teknikal Tim Sevice Call Reservation Page';
require_once $_SERVER['DOCUMENT_ROOT'] .'/core/init.php';
$newsMessage = 'temp message';

$servicecallsdb = DB::getInstance()->get('tt_service_calls', array('UserID',
 '=','$_SESSION['UserID']));

if(!$servicecallsdb) {
// $servicecalls[] = array('ID'=>'','ServiceCallDescription'=>'No Service Calls');
} else {
$servicecalls = $servicecallsdb->results();
}
include 'servicecalls.html.php';



?>

然后显示信息,我检查servicecalls是否已设置,并有一个大于0的计数,记住,它不是一个数组,我引用,所以我访问的记录与对象操作符“->”像这样:

<?php include $_SERVER['DOCUMENT_ROOT'] .'/includes/header.html.php';?>
<!--Main content-->
<div id="mainholder"> <!-- div so that page footer can have a minum height from the
  header -->
<h1><?php if(isset($pagetitle)) htmlout($pagetitle);?></h1>
<br>
<br>
<article>
    <h2></h2>
</article>
<?php
if (isset($servicecalls)) {
if (count ($servicecalls) > 0){
     foreach ($servicecalls as $servicecall) {
        echo '<a href="/servicecalls/?servicecall=' .$servicecall->ID .'">'
  .$servicecall->ServiceCallDescription .'</a>';
    }
}else echo 'No service Calls';

}

?>
<a href="/servicecalls/?new=true">Raise New Service Call</a>
</div> <!-- Main content end-->
<?php include $_SERVER['DOCUMENT_ROOT'] .'/includes/footer.html.php'; ?>

其他回答

它不是数组,而是stdClass类型的对象。

你可以像这样访问它:

echo $oResult->context;

更多信息在这里:什么是stdClass在PHP?

今天遇到同样的问题,是这样解决的:

如果你调用json_decode($somestring),你会得到一个对象,你需要访问像$ Object ->key,但如果你调用json_decode($somestring, true),你会得到一个字典,可以访问像$array['key']

下面是函数签名:

mixed json_decode ( string $json [, bool $assoc = false [, int $depth = 512 [, int $options = 0 ]]] )

当param为false(默认值)时,它将返回适当的php类型。您可以使用object获取该类型的值。方法范式。

当param为true时,它将返回关联数组。

它将在错误时返回NULL。

如果你想通过数组获取值,将assoc设置为true。

试试像这样的东西!

而不是像这样获取上下文(这适用于获取数组下标)

$result['context']

尝试(获取对象的工作)

$result->context

其他例子是:(如果$result有多个数据值)

Array
(
    [0] => stdClass Object
        (
            [id] => 15
            [name] => 1 Pc Meal
            [context] => 5
            [restaurant_id] => 2
            [items] => 
            [details] => 1 Thigh (or 2 Drums) along with Taters
            [nutrition_fact] => {"":""}
            [servings] => menu
            [availability] => 1
            [has_discount] => {"menu":0}
            [price] => {"menu":"8.03"}
            [discounted_price] => {"menu":""}
            [thumbnail] => YPenWSkFZm2BrJT4637o.jpg
            [slug] => 1-pc-meal
            [created_at] => 1612290600
            [updated_at] => 1612463400
        )

)

然后试试这个:

foreach($result as $results)
{
      $results->context;
}

使用true作为json_decode的第二个参数。这将把json解码成一个关联数组,而不是stdObject实例:

$my_array = json_decode($my_json, true);

有关详细信息,请参阅文档。