Internet Explorer 11 JavaScript：对象是静态的

Question

Using the interactive console in IE11 (F12), I have static object

user=> a={a:5,b:6}
  [object Object] { a : 5 , b : 6 }
user=> a.l=6
  object does not support this property 

The first line of the Console says :

The attached page targets document mode 5. Some console APIs and features may not be available.

Yes, indeed, some API are not accessible!

How can I get dynamic object with javascript in IE11?

Answer 1

You've set your document mode to 5 (Internet Explorer 5), change it back to 11:

Answer 2

In my case, the document was a document in a frame windows.

So, I added the following line in the header of the html document that countains the frameset tag.

<meta http-equiv="X-UA-Compatible" content="IE=10" />

Then the message did not appears again. It seems that the problem was solved and that attribute can be added dynamically as in the w3c norm.