php一维数组改变元素或者新增元素

$json = '{"name":"fdipzone","date":"2016-10-10"}';
$data = json_decode($json, true);
$data['xxx'] = 'abc';//新增
$data['name'] = 'abc';//改变值
$data['date'] = '2017-10-10';//改变值
$result = json_encode($data);
echo $result; // 修改后数据