Testing for a feature of regex compilation in IE11

Question

I would like to test for Unicode Regex Property Escapes to avoid compiling a broken regular expression in browsers that do not support it (for example IE11). Ideally, I\'d like

Answer 1

This works in Firefox or Safari; should be okay in IE11:

let regex = /somereplacementregex/;
try
{
    regex = new RegExp ("\\p{Emoji_Modifier_Base}\\p{Emoji_Modifier}?|\\p{Emoji_Presentation}|\\p{Emoji}\\uFE0F", "gu");
}
catch (e) { }
//
// use regex...
console.log (regex);