JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = "<div id='1'></div><div id='asdf'><input type='text' id='2'/></div>",
    numCompare = 23,
    div = $("<div>"),
    i, cur;

div.append(data);

div.find("[id]").each(function () {
    $(this).attr("id", function (index, attr) {
        return attr + "_" + numCompare;
    });
});

console.log(div.html());