1429791 - IE support on Array.prototype.forEach() page is wrong

Status: RESOLVED WORKSFORME

(Developer Documentation Graveyard :: JavaScript, defect, P1)

Description

[jpkant]

:: Developer Documentation Request

      Request Type: Correction
     Gecko Version: unspecified
 Technical Contact: 

:: Details

When I used forEach() in IE 11, I got the error `SCRIPT438: Object doesn't support property or method 'forEach'`. Supported version on the page says 9 when the method doesn’t work at all.

Comment 1

[Julien G]

Could you paste a jsfiddle/codepen example where you reproduce the issue?
I've tried the following https://codepen.io/anon/pen/EoLNZW with an IE11 and it works fine (you can open the console with the button located in the bottom/left corner of the page).

Comment 2

[jpkant]

Well, it looks like this is an issue with DOM-related objects then. I got the error while trying to loop through `document.querySelectorAll("p")` and print the `innerHTML`s.

https://codepen.io/jkantner/pen/ypEoMq

Comment 3

[Julien G]

Then, this is not due about the support of forEach for Arrays but for NodeList (the type of object returned by querySelectorAll). As written on https://developer.mozilla.org/en-US/docs/Web/API/NodeList#Browser_compatibility, IE doesn't implement generic iteration methods for NodeList.

@jpkant: if you edit your codepen to directly use an array instead of document.querySelectorAll, you'll see the console populated with the results instead of the error.

All in all, I think both forEach and NodeList page provide the right compatibility data, feel free to comment.

Comment 4

[jpkant]

Okay, I see. Then partial support should have been noted somewhere.

Comment 5

[Julien G]

Partial support is indicated on the Browser Compatibility section of the NodeList article(cf. https://developer.mozilla.org/en-US/docs/Web/API/NodeList#Browser_compatibility ). This table contains two rows: one for the basic behavior and a second one about iteration methods. This second row states that IE doesn't support (yet) forEach to iterate through a NodeList object.