What will be the output of the following code?

console.log(1 + "2" + "2");

console.log(1 + +"2" + "2");

console.log(1 + -"1" + "2");

console.log(+"1" + "1" + "2");

What’s the value of :

console.log(typeof(undefined))?

What will be the output of the following code?

let a = 3;

let b = new Number(3);

let c = 3;




console.log(a == b);

console.log(a === b);

console.log(b === c);

What will the following code return?

console.log(typeof typeof 1);

What will be logged to the console?

function() {

   var a = b = 5;

})();

console.log(b);

console.log(typeof a);

What is the output of the following code?

let y = 1;

if (function f() {}) {

    y += typeof f;

}

console.log(y);

What will be the output of the following code?

console.log(0.1 + 0.2 === 0.3);

What will the following code output?

console.log(1 < 2 < 3);

console.log(3 > 2 > 1);

What will be the output?

function sayHi() {

  console.log(name);

  console.log(age);

  var name = "Lydia";

  let age = 21;

}

sayHi();

What’s the output?

for (var i = 0; i < 3; i++) {

  setTimeout(() => console.log(i), 1);

}

What will be the output?

const obj = { a: "one", b: "two", a: "three" };

console.log(obj);

What’s the output?

const a = {};

const b = { key: “b” };

const c = { key: “c” };

a[b] = 123;

a[c] = 456;

console.log(a[b]);

What will the following code output?

let a = 3;

let b = new Number(3);

console.log(a == b);

console.log(a === b);

console.log(typeof a);

console.log(typeof b);

What does the following code print?

console.log(("b" + "a" + + "a" + "a").toLowerCase());

What will be logged?

let person = { name: "Lydia" };

const members = [person];

person = null;

console.log(members);

What will be logged?

function checkAge(data) {

  if (data === { age: 18 }) {

    console.log("You are an adult!");

  } else if (data == { age: 18 }) {

    console.log("You are still an adult.");

  } else {

    console.log("Hmm.. You don't have an age I guess");

  }

}

checkAge({ age: 18 });

What’s the output?

function sum(a, b) {

  return a + b;

}

var x

x=sum(1, "2");

console.log(x)

What will be the output?

let number = 0;

console.log(number++);

console.log(++number);

console.log(number);

What’s the value of the output?

const arr = [1, 2, 3];

arr[10] = 10;

console.log(arr.length);

What will be the output?

const foo = () => console.log("First");

const bar = () => setTimeout(() => console.log("Second"));

const baz = () => console.log("Third");

bar();

foo();

baz();

What will be the output?

const person = {

  name: "Lydia",

  age: 21

};

for (const item in person) {

  console.log(item);

}

What’s the output?

console.log(String("11") === 11);

What will be the output?

const numbers = [1, 2, 3];

numbers[9] = 11;

console.log(numbers);

What’s the output?

function sum(a, b) {

  return a + b;

}

const answer = sum`Hello``World`;

console.log(answer);

Consider the following code. What will be the output?

let array = [1, 2, 3, 4, 5];

let newArray = array.slice(1, 3);

console.log(newArray);

What’s the output?

let x = 10;

let y = "10";

console.log(x == y);

console.log(x === y);

What will the following code output?

var x = 21;

var girl = function() {

  console.log(x);

 var x = 20;

};

girl();

What’s the value of `result`?

const result = eval('20 / 5 + 3 * 4');

console.log(result)

What’s the output?

var name = 'John';

var obj = {

   name: 'Colin',

   getName: function() {

         return this.name;

      }

 };


var anotherObj = { name: "Charlie" };

var boundFunction = obj.getName.bind(anotherObj);

console.log(obj.getName());

console.log(boundFunction());

What will the following code output?

console.log(typeof NaN);

console.log(NaN === NaN);