JSFiddle - React, Tailwind, and code Playground

JavaScript

var container = $('<div/>');
var iframe_jquery = $("<iframe>")
    .addClass("foo")
    .appendTo(container); 

var iframe = iframe_jquery.get(0);
if (iframe){ // iFrame exists
    console.log("contentWindow is:", iframe.contentWindow);
}
container.appendTo($('body'));
   console.log("contentWindow is now:", iframe.contentWindow);