JSFiddle - React, Tailwind, and code Playground

JavaScript

RegExp.quote = function(str) {
    return (str+'').replace(/([.?*+^$[\]\\(){}|-])/g, "\\$1");
};


var adHtmltext ="this is ashok"

alert(1)
var regExpPattern = new RegExp(RegExp.quote("this"), "igm"); 
alert(2)
adHtmltext = adHtmltext.replace(regExpPattern, "$$Ashok");
alert(3)
alert(adHtmltext );