我无法使用 array_key_exist 为 json 响应获取指定的键

Question

$status_key ="status"

$response = {"error":false,"data":{"id":16420728,"order_id":"5000","mobile_no":"9995088810","amount":20,"balance":46.89,"status":"failure","tnx_id":"","response":"Transaction Failed"}}"

$result = json_decode($response);

这打印：

{ 

    ["error"]=> bool(false) 

    ["data"]=> object(stdClass)#24 (8) { 

        ["id"]=> int(16420728) 

        ["order_id"]=> string(4) "5000" 

        ["mobile_no"]=> string(10) "9995088810" 

        ["amount"]=> int(20) 

        ["balance"]=> float(46.89) 

        ["status"]=> string(7) "failure" 

        ["tnx_id"]=> string(0) "" 

        ["response"]=> string(18) "Transaction Failed" 

    }

}

现在我正在检查指定的密钥

var_dump(array_key_exist(status_key,result));

当我执行var_dump()此功能时，它返回"bool(false)"