JSFiddle - React, Tailwind, and code Playground

HTML

<div id="r"></div>

JavaScript

function dotted_put(str,val) {
    var oper=str.split('.');
    var p=window;
    for (var i=0;i<oper.length-1;i++) {
        var x=oper[i];
        p[x]=p[x]||{};
        p=p[x];
    }
    p[oper.pop()]=val;
}

dotted_put('test.hello.world', 'testvalue');

var output=test.hello.world;
var el=document.getElementById('r');
el.innerText = output;
el.textContent = output;