JSFiddle - React, Tailwind, and code Playground

HTML

<div id="output"></div>

JavaScript

function isFunction(fntype) {
    return (fntype == typeof(Function));
}

var obj;
var yep = function () { };
var output = "";

try {
    output += "isFunction(obj)  == " + isFunction(typeof obj) + "<br>";
    output += "isFunction(yep)  == " + isFunction(typeof yep) + "<br>";
    output += "isFunction(nope) == " + isFunction(typeof nope) + "<br>";
} catch (e) {
    output += "error: " + e + "<br>";
}

$("#output").html(output);