Skip to main content

javascript snippets interview questions set 1

 

javascript snippets interview questions set 1

Hey, I have just started a new set for javascript snippets interview questions which will make your understanding of javascript more clear.It's more like testing your knowledge and then clearing things that you have doubt or if you have heard for the first time about it.

So let's begin with testing and improving yourself,

Q1. Which operator returns true if the two compared values are not equal?

 a)<>

 b)~

 c)==!

 d)!==



Q2. How is a forEach statement different from a for a statement?

 a)Only a for statement uses a callback function.

 b)A for statement is generic, but a forEach statement can be used only with an array.

 c)Only a forEach statement lets you specify your own iterator.

 d)A forEach statement is generic, but a for statement can be used only with an array.



Q3. Which statement creates a new object using the Person constructor?

 a)var student = new Person();

 b)var student = construct Person;

 c)var student = Person();

 d)var student = construct Person();



Q4. When would the final statement in the code shown be logged to the console?

let modal = document.querySelector('#result');

setTimeout(function(){

    modal.classList.remove('hidden);

}, 10000);

console.log('Results shown');

 a)after 10 second

 b)after results are received from the HTTP request

 c)after 10000 seconds

 d)immediately



Q5. You've written the code shown to log a set of consecutive values, but it instead results 

in the value 5, 5, 5, and 5 being logged to the console.

Which revised version of the code would result in the value 1, 2, 3 and 4 being logged?

 for (var i=1; i<=4; i++){

    setTimeout(function(){

        console.log(i);

    }, i*10000);

   }

a) for (var i=1; i<=4; i++){ (function(i){ setTimeout(function(){ console.log(j); }, j*1000); })(j) }


b) while (var i=1; i<=4; i++) { setTimeout(function() { console.log(i); }, i*1000); }


c) for (var i=1; i<=4; i++) { (function(j) { setTimeout(function(){ console.log(j); }, j*1000); })(i) }


d) for (var j=1; j<=4; j++) { setTimeout(function() { console.log(j); }, j*1000); }



Q6. What is the result in the console of running this code?

"use strict";

function logThis() {

    this.desc = "logger";

    console.log(this);

}

new logThis();

a) undefined

b) window

c) {desc: "logger"}

d) function


I hope you like the article. Please stay connected for more such articles.

Please check the comment sections for answers and if any doubts let me know there. 


You can also follow me on Twitter or Linkedin for the latest updates.

Written By:

Saurabh Joshi

Comments

  1. 1) Explanation:
    !== not equal value or not equal type
    var x = 5,
    x !== 5 false
    x !== "5"true
    x !== 8 true

    ReplyDelete
  2. 6)Explanation:
    When you call a function with new keyword,
    JavaScript creates a new empty object. If ‘this’ keyword is used within that function, it refers to the newly created empty object.
    If you’re not explicitly returning any object,
    JavaScript would return that newly created object/

    ReplyDelete
  3. I think Q5.c has typo. it should be ( , instead of { before fitst function for IIFE

    ReplyDelete

Post a Comment

Popular posts from this blog

Coding Interview Questions Set 1

From this article, I will be sharing with you all a series of articles on coding interview questions. So please stay connected for the latest set of questions. It will be a good brainstorming exercise and will also prepare you for coding interviews and will definitely boost your confidence. So let's start, 1)Reverse of a string with only O(1) extra memory. Solution: var reverse = function(string) {     let result = ''     for(let i= string.length -1; i >= 0; i--){         result += string[i];     }     return result; }; 2)Fizz Buzz: Write a program that will accept a number n and will output number till n but for multiples of three it should output “Fizz” instead of the number and for the multiples of five output “Buzz”. For numbers which are multiples of both three and five output “FizzBuzz”. Solution: var fizzBuzz= function(n) {     const arr=[]     for(i=1; i<=n; i++){ ...

JavaScript: Debouncing | Flipkart UI Interview Question.

To understand this programming practice will go with a quick example. We all do online shopping and we do search for products on Flipkart on the search bar. So when we type on search bar i.e on every keypress we are actually giving API requests to the server, which in response gives us suggestions. Actually, it's a time-consuming task and may degrade the performance of the webpage. So to improve the performance we use debounce function which actually acts as a controller which reduces the API request to the server on keypress event. In simple terms, we are giving API request only after a certain amount of time between two keypress events. A debounce is a higher-order function. Higher-order function: A function that returns another function. Let's dive deep: HTML Code: <input type="text" onkeyup="searchProducts()"/> Consider this as a search bar for Flipkart. On any keypress, we are calling searchProducts() function. Javascri...

Node.js: Bundling your Node.js application to single executable for Windows.

In this article, we will see how to bundle Node.js application to a single executable for Windows. What's the need? Well recently, I had taken a work where I needed to convert pdf's(Of similar format) to excel sheet. So I was reading the pdf's from a folder in desktop and I was storing the output excel sheet into a separate folder on the desktop. I used Node.js for the program. Now the client wanted it to install the program on 25 windows machine and his budget was really low. So it was also not possible for me to install node.js for 25 machines and then install the required dependency for each one. One of the solution: While I was searching for an easy solution I found this amazing npm module pkg . This module can make your node.js app work like plug and play type. No need to install Node.js on the client machine or any other dependency.  It helps to make a commercial or trial version of your node.js application without exposing the source code. I found ...