PHPでJSONのコンテンツを取得する方法について話しましょう

$a = '{"status":"3","message":"","errCode":"0","data":[{"time":"2014-12-12 20:37","context":"到达：湖南湘潭公司 已收件"},{"time":"2014-12-12 21:31","context":"到达：湖南湘潭公司 发往：福建厦门分拨中心"},{"time":"2014-12-13 02:24","context":"到达：湖南长沙分拨中心"},{"time":"2014-12-17 20:02","context":"到达：福建厦门公司国贸分部 发往：福建厦门公司国贸分部"},{"time":"2014-12-17 20:33","context":"到达：福建厦门公司国贸分部 由 图片 签收"}],"html":"","mailNo":"1201519497579","expTextName":"韵达快递","expSpellName":"yunda","update":"1420006818","cache":"0","ord":"ASC","tel":"021-39207888"}';
 
$b = json_decode($a);
$status = $b->status;
....
$message = '';
foreach($b->data as $v){
    $message .= $v->time.'  '.$v->context."\r\n";
}

$jsonString = '....your json....';
$result = json_decode($jsonString, true);
$dataCount = count($result['data']);
if ($dataCount > 0) {
    for ($i = 0; $i < $dataCount; $i++) {
        // 这里处理每一条物流状态
    }
}

for ($i = 0; $i < $dataCount; $i++) {
        // 这里处理每一条物流状态
    }
 这个for里面要怎么写才能调用time 跟context这2个内容 呢

    
    
    //引入jquery的CDN