Q:

IE11 Regular Expression Unexpected Result

I have this regular expression /(\d\d|\d).(\d\d|\d)/ and I'm executing it on 06/16/2018 as the input string.  In Chrome, it works as expected, giving ["06/16", "06", "16"] as the match results.  In IE11, it's giving me ["2018", "20", "8"] as the results.  However, when I attempt to recreate it in the console directly, it works fine in both browsers.  Any idea what could be happening here? 
For background, this is actually executed in a third party library flatpickr v4.5.0 but I'm debugging that code to see what's happening. 
See below screenshot from the IE11 debugger for an example.  I can't figure out how this could be happening. 

It doesn't make any sense to me, how could (\d\d|\d).(\d\d|\d) match 06/16/2018 as 2018 instead of 06/16.  Also, look at match's index property.  11?  How is that even possible?  The input string's length is only 10. 
Here's a link to a code sandbox where this is demonstrated. 

A:

I ended up figuring out the issue, so I wanted to follow up here for anyone that finds this in the future. 
As you can see in the code sandbox link that I posted above, I was getting the formatted date string by using Date.toLocaleDateString.  Apparently, in IE11 (and Edge), there are some additional Left-To-Right characters included, which was throwing off the parsing of the formatted date value.  Once I got rid of these characters, this issue was resolved. 
For reference, here's the GitHub issue I opened to track this issue: https://github.com/IBM/carbon-components-react/issues/1325

