Full Stack Developer Interview Question And Answers For Freshers

Full Stack Developer Interview Question And Answers For Freshers

Arun R's photo
Arun R
·Dec 17, 2022·

4 min read

Fullstack is all about building versatility, Every application has a User Interface and a server to process the request and a database to store data these steps together are called Fullstack and the average salary of the Full Stack Developer is above 5 LPA, Full-stack developers have to handle the work with the both client-side and the server-side of the application which gives the developer more hold over the product, In this article, We will go through some of the important Full Stack Developer Interview Question And Answers For Freshers.

1. What is the difference between var, Let and const in javascript?

In JavaScript, there are three different types of keywords to declare variables, Main differences between the three keywords are based on scope, hoisting, redeclaration and reassignment.

2. What is a RESTful API?

REST is the most common communication standard between computers over the internet where API stands for Application Programming Interface is like a pathway between two computers to talk with each other. The common Application Programming Interface used by most mobile and web applications to talk to servers is called REST where REST stands for Representational State Transfer.

3. How does the map method work on JavaScript Arrays?

The map() method is used to create a new array with the results of calling a provided function on every element in an array.

var array1 = [2, 4, 6, 8];

const map1 =


return x * 2




[4, 8, 12, 16]

The map makes a callback function for every element in the array and constructs a new array from the results. Callback invokes an indexes array that has assigned values, including undefined values.

4. What is Continuous Integration?

Continuous Integration (CI) is a process where developers integrate their code into a shared repository to find errors early. The continuous integration process involves automatic tools which help the state of new code correctness before the integration.

5. What do you mean by CORS?

CORS refers to Cross-Origin Resource Sharing, CORS browser mechanism allows web pages in one domain to have controlled access to resources in another domain.

6. Difference between state and props?

Both props and states are plain JavaScript objects. While both hold information that influences the render output, Both props and state are different in their functionality concerning components. Props pass components that are similar to their function parameters, In other cases, the state managed within the component is parallel to a variable declared within a function.

7. What is long polling?

Long polling is the easiest way to maintain a persistent connection with the server and it holds the request until it has a responsibility to send it back. In the case of no response, the connection will hang until some movement is sent back.

8. What are the limitations of React?

  • React is a library, not a full framework.

  • Integrating React with the traditional MVC framework requires some more amount of additional configuration.

  • The complexity of the code increases with inline templating and JSX.

9. What is a callback? Can you show an example using one?

Callbacks are functions passed as an argument to another function to be executed once an event has occurred or a certain task is complete, often used in asynchronous code. Callback functions are invoked later by a piece of code but can be declared on initialization without being invoked.

As an example, event listeners are asynchronous callbacks that are only executed when a specific event occurs.

function callback() {

console.log("I am a callback function.")

document.addEventListener("click", callback)

However, callbacks can also be synchronous. The following map function takes a callback function that is invoked synchronously for each iteration of the loop (array element).

const map = (arr, callback) => {

  const result = []

  for (let i = 0; i < arr.length; i++) {

result.push(callback(arr[i], i))


  return result

map([1, 2, 3, 4, 5], n => n * 2) // [2, 4, 6, 8, 10]


The above-mentioned questions are the most commonly asked full-Stack developer Interview Question And Answers For Freshers. In our upcoming series of blogs, we will also add an advanced level of Full Stack developer Interview Q&A to this blog that is prevalent in the Industry.

Also, read our Article:

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