for…of-JavaScript关键字Internet Explorer解决方法

Question

I am using “for...of” in many places in my Javascript code which is a new technology, part of Javascript's new specification (ECMAScript 2015 (E56) standard). "for...of" is supported in Chrome, Safari and Firefox. Though, IE doesn't yet support this new feature ( See this link ). What would be my best approach to support these 4 main browsers - do I revert to "for in/for loop" or do I use browser-sniffing code or is there a better hack to be able to both use some hybrid "for...of" and "for...in"? This is not a repeat of this question here: link_here because I am aware that IE does not support "for...of". What I am looking for is if there is a hack to still use it and still support all the 4 browsers I listed?

Answer 1

You can add the Traceur compiler:

 <script src="https://google.github.io/traceur-compiler/bin/traceur.js"></script> <script src="https://google.github.io/traceur-compiler/src/bootstrap.js"></script> <script type="module"> for(var n of ['foo', 'bar']) alert(n); </script> 

It should work even on IE9.

Answer 2

If you want back compat support for "for...of" your only choice is a compiler (transpiler). If you look here: https://kangax.github.io/compat-table/es6/ the well known compilers, and the level of support they provide, are well documented.