exebook提出了一个问题：Why [object Object] mentions “object” twice?，或许与您遇到的问题类似。
All objects have a
toString method that displays something in the format
[object type], where type is the object type.
When called on
null you get
[object Null] and when called on an object you get the string
[object Object] because it's based on the Object constructor (capital "O"), that's why it says
object twice, it's an object of the type Object.