questions about Javascript questions

questions.js

//1. returned values
(function () {}) === (function () {}) // ==>
(function () {}) == (function () {}) // ==>
(function () {}) == (function () {})() // ==>
(function () {})() == (function () {})() // ==>
(function () {})() === (function () {})() // ==>
(function () {})() == undefined // ==>
(function () {})() == null // ==>
null === (function () {})() // ==>
(function () {})() === undefined // ==>


//2. three ways to generate undefined value


//3. variable shadowing
(function (x) {
  console.log(x);
  
  (function () {
    var x;
    console.log(x);
    x = 22
    console.log(x);
  })();

  console.log(x)
})(2)

//4.1 function naming
var viri = function wero () {
  console.log(viri);
  console.log(wero);
}

viri();
wero();

//4.2 function naming
var x;
console.log(wero())

function wero () {
  return x;
}
var x = 22;