JSFiddle - React, Tailwind, and code Playground
JavaScript
string = '12345ext999'
var extensions = ['x','ex','ext']
for (var i = 0; i < extensions.length; i++) {
var regex;
replace = '#'
regex = new RegExp(extensions[i], "g");
replaceString = string.replace(regex, replace);
}
console.log(replaceString)