JSFiddle - React, Tailwind, and code Playground

JavaScript

var i  = (![] == false) && ([] == false);
alert("(![] == false) && ([] == false) === "+i);
var j = undefined;
alert("Given var j = undefined:\n" +
      "(true == j) === " + (true == j) + "\n" +
      "(false == j) === " + (false == j) + "\n" +
      "(true == !j) === " + (true == !j) + "\n" +
      "(false == !j) === " + (false == !j));
var k = Infinity;
alert("Given var k = Infinity:\n" +
      "(true == k) === " + (true == k) + "\n" +
      "(false == k) === " + (false == k) + "\n" +
      "(true == !k) === " + (true == !k) + "\n" +
      "(false == !k) === " + (false == !k));
var l = NaN;
alert("Given var l = NaN:\n" +
      "(true == l) === " + (true == l) + "\n" +
      "(false == l) === " + (false == l) + "\n" +
      "(true == !l) === " + (true == !l) + "\n" +
      "(false == !l) === " + (false == !l));