Тест по JavaScript — Что будет в консоли?

console.log(a);
var a = 10;

console.log(b);
let b = 10;

for (var i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}

for (let i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}

var a = 10;
(function() {
  var a = 20;
  console.log(a);
})();

console.log(this);

console.log([] == ![]);

console.log(typeof new Function());

console.log('5' - true);

let a = 10;
{
  let a = 20;
}
console.log(a);

console.log(null == undefined);

console.log(null === undefined);

const obj = {
  a: 2,
  b: function() {
    return this.a;
  }
};
console.log(obj.b());

const obj = {
  a: 3,
  b: () => this.a
};
console.log(obj.b());

console.log(typeof null);

function test() {
  var x = 1;
}
console.log(x);

console.log(typeof function() {});

console.log({} === {});

console.log(parseInt('0xff', 10));

console.log(1 + '1');