JSFiddle - React, Tailwind, and code Playground

by Alexey Ukolov

HTML

<button></button>

JavaScript

class Foo {
  constructor() {
    this.bar()
  }

  bar() {
    console.log(1, this);
  }

}

let foo = new Foo();

/*******************************************/
foo.bar();

/*******************************************/
let btn = document.querySelector('button');
btn.addEventListener('click', foo.bar);

/*******************************************/
function glob() {
  function inFoo() {
    console.log(2, this);
  }

  inFoo();
}

glob();