如何从PHP中的对象获取整数

I have an object that looks like this when I var_dump it:

array(1) { [0]=> object(stdClass)#958 (5) { 
 ["id"]=> int(54) 
 ["user_id"]=> int(101)  
 ["score"]=> string(3) "3.0" 
 ["created_at"]=> string(24) "2015-09-14T17:49:42.649Z" 
 ["updated_at"]=> string(24) "2015-09-14T17:49:42.649Z" } 
} 

I can get the string values just fine. For example:

$myObject->score;

Gives me what I want.

But if I try and get an integer (let's say user_id) the same way, I get a null value.

$myObject->user_id;

Any ideas here? I've played around with typecasting, but haven't had any luck.