JSFiddle - React, Tailwind, and code Playground

HTML

<div class="output">Here's the output:<ol></ol></div>

JavaScript

var x = "Global scope";
    var y = "Not changed.";
    
    function Foo() {
        this.x = "Attribute of foo";
        var x = "In foo's closure";
        y = "Changed!"
        this.getX = function () { 
            return x;
        }
    }
    function log(astr) {
        $("div.output ol").append("<li>"+astr+"</li>");
        }
    // do some logging

    log(x); // "Global scope"
    log(y); // "Not changed"
    foo = new Foo();
    log(y); // "Changed!"
    log(foo.x); // "Attribute of foo"
    log(x); // "Global scope"
    log(foo.getX()); // "In foo's closure"