JSFiddle - React, Tailwind, and code Playground

JavaScript

(function () {
    alert(foo() === 1 ? 'Function is defined' : 'Shouldn\'t happen.')
    alert(bar   === 2 ? 'Shouldn\'t happen.'  : 'Variable exists, but has undefined!')
    function foo() {
        return 1
    }
    var bar = 2;
})();