JSFiddle - React, Tailwind, and code Playground

HTML

<div id="status" style="width:100%;height:100%;"></div>

JavaScript

var status = document.getElementById("status");
var obj = {
  prop_1: 1,
  prop_2: 2,
  myMethod: function() {
    var t = this;
    // use t instead of this
    t.prop_1 = 43 - t.prop_1;

    return t.prop_1;
  }
}

status.innerHTML = obj.myMethod();