Warning: E4X is obselete. It’s been disabled by default for chrome in
Firefox 17,and completely removed in Firefox 21. Use
DOMParser/DOMSerializer or a non-native JXON algorithm instead.
https://developer.mozilla.org/en-US/docs/Archive/Web/E4X/Processing_XML_with_E4X
解决方法
As Brendan said somewhere “E4X is crazyland”,and FF’s implementation of E4X deviates from the spec in ways that are not written down anywhere.
— Mark S. Miller
The only way for it to come back would be via a new edition of ECMA-357,which Adobe and Mozilla were going to work on. Until then,it’s out.
— Brendan Eich
The idea behind it wasn’t bad,but the way it was integrated into the language was. SpiderMonkey was the only JS engine that ever implemented it,and there were endless problems caused by that and severe complications of the engine’s implementation required for this support.
— Till Schneidereit
