Hey all, I’m from the Aditya Institute of technology and management. Recently I attended an interview to be a lead in GDSC in Web Development.
It’s quite a very easy process. We register ourselves through a link from the GDSC website. Later we get a Zoom Interview Schedule from the Team Overall Lead of the College via mail.
The meet link will be shared 5 minutes before the interview and we need to join. As I attended for Web Development. Questions on HTML, JavaScript, Node Js, and React Js were asked. A few concepts on Mongo DB were also Asked.
Questions Like.
HTML:
- What is HTML, and what does it stand for?
– HTML stands for HyperText Markup Language. It is the standard markup language used to create web pages.
- What is the basic structure of an HTML document?
– An HTML document typically consists of an opening `<html>` tag, followed by `<head>` and `<body>` sections. The `<head>` contains metadata, while the `<body>` contains the content displayed on the web page.
- What is the purpose of HTML tags?
– HTML tags are used to structure content and provide instructions to web browsers on how to display that content. They are enclosed in angle brackets, like `<tag>`.
- What is the difference between HTML and HTML5?
– HTML5 is the latest version of HTML, and it introduced new elements, attributes, and APIs for better multimedia support, improved semantics, and enhanced performance compared to previous versions of HTML.
- How do you create a hyperlink in HTML?
– You can create a hyperlink using the `<a>` (anchor) element. You specify the URL in the `href` attribute. For example: `<a href=”https://www.example.com”>Visit Example</a>`.
- What are semantic HTML elements, and why are they important?
– Semantic HTML elements are tags that convey meaning about the structure and content of a web page. They help improve accessibility, SEO, and the overall structure of a webpage. Examples include `<header>`, `<nav>`, `<article>`, and `<footer>`.
- What is the purpose of the `<meta>` tag in HTML?
– The `<meta>` tag is used to provide metadata about the HTML document, such as character encoding, page description, author, and keywords. It is often placed within the `<head>` section.
- How do you embed an image in an HTML document?
– You can embed an image in HTML using the `<img>` element. You specify the image source in the `src` attribute. For example: `<img src=”image.jpg” alt= “Image description”>`.
- Explain the difference between a block-level element and an inline element in HTML.
– Block-level elements create a new block formatting context and typically start on a new line, taking up the full width of their container. Examples include `<div>`, `<p>`, and `<h1>`. Inline elements, on the other hand, do not create new lines and only take up as much width as necessary. Examples include `<span>`, `<a>`, and `<strong>`.
- How can you create a numbered (ordered) list and a bulleted (unordered) list in HTML?
– To create an ordered list, use the `<ol>` element with `<li>` elements inside it. For an unordered list, use the `<ul>` element with `<li>` elements.
Javascript:
- What is JavaScript, and how does it differ from Java?
– JavaScript is a dynamic, interpreted scripting language primarily used for web development, whereas Java is a statically typed, compiled language often used for a wide range of applications. Despite their similar names, they are distinct languages.
- What are the data types in JavaScript?
– JavaScript has six primary data types: Number, String, Boolean, Object, Undefined, and Null. There’s also a seventh data type called Symbol, introduced in ECMAScript 6.
- Explain hoisting in JavaScript.
– Hoisting is a JavaScript behavior where variable and function declarations are moved to the top of their containing scope during the compilation phase. However, only variable declarations are hoisted, not their initializations.
- What is the difference between `let`, `const`, and `var` for variable declaration?
– `let` and `const` are block-scoped, and `var` is function-scoped. `const` is used for constants and cannot be reassigned after declaration. `let` and `var` can be reassigned.
- Explain the event delegation in JavaScript.
– Event delegation is a technique in which a single event handler is attached to a common ancestor of multiple elements instead of attaching individual handlers to each element. It’s useful for improving performance and managing dynamically added elements.
- What is the purpose of closures in JavaScript?
– Closures are functions that have access to variables from their containing (enclosing) function, even after the outer function has finished executing. They are often used for data encapsulation and maintaining state.
- How does prototypal inheritance work in JavaScript?
– JavaScript uses prototypal inheritance, where objects can inherit properties and methods from other objects. Each object has a prototype chain that links to other objects, allowing for inheritance and sharing of properties.
- Explain the concept of asynchronous programming in JavaScript and how it’s achieved.
– Asynchronous programming in JavaScript is used to handle tasks that don’t block the main execution thread. It’s achieved through mechanisms like callbacks, Promises, and async/await, allowing non-blocking, concurrent operations.
- What is the “this” keyword in JavaScript, and how does its value change based on context?
– The “this” keyword refers to the current execution context. Its value can change depending on how a function is called (e.g., method invocation, constructor, global context). Understanding the context is crucial for proper usage.
- What is the purpose of the Document Object Model (DOM) in JavaScript?
– The DOM is a programming interface for web documents. It represents the structure of a web page, allowing JavaScript to interact with and manipulate the content, structure, and style of a web page dynamically.
Node.js:
- What is Node.js, and how does it differ from traditional JavaScript?
- How do you handle asynchronous operations in Node.js, and what is the event loop?
- Explain the difference between callback, promises, and async/await in Node.js.
- What is the purpose of the `package.json` file in a Node.js project, and what are its key properties?
- Describe the CommonJS module system and how it is used in Node.js.
- What is npm, and how can you use it to manage dependencies in a Node.js project?
- How do you handle and prevent callback hell (or the “Pyramid of Doom”) in Node.js code?
- Explain the concept of middleware in Express.js. Why is it essential, and how do you use it?
- What is the difference between Node.js and JavaScript in the browser in terms of global objects and APIs?
- How can you scale a Node.js application to handle increased traffic and maintain performance?
React.js:
- What is React.js, and what problems does it solve in web development?
- What are the key differences between React functional components and class components?
- Explain the concept of virtual DOM in React and how it improves performance.
- How do you pass data from a parent component to a child component in React?
- Describe the component lifecycle methods in React. What are the most commonly used lifecycle methods?
- What is JSX, and how does it differ from HTML in React components?
- What is the purpose of state in React, and how do you update it?
- How do you handle form input and controlled components in React?
- What are React hooks, and how do they differ from class component state and lifecycle methods?
- Describe the differences between React Router and the standard browser routing mechanisms, and how do you implement client-side routing in a React application.
MongoDB:
- What is MongoDB, and how does it differ from traditional relational databases?
MongoDB is a NoSQL, document-oriented database that stores data in BSON format. It differs from traditional databases in terms of its flexible schema, horizontal scalability, and JSON-like document storage.
- What is a BSON and JSON format in the context of MongoDB?
BSON (Binary JSON) is the binary-encoded serialization of JSON-like documents used in MongoDB. BSON allows for efficient storage and manipulation of data.
- What is a collection and a document in MongoDB?
In MongoDB, a collection is a group of MongoDB documents that share a common set of fields and a document is a unit of data in MongoDB, composed of key-value pairs.
- How does MongoDB ensure high availability and fault tolerance?
MongoDB achieves high availability and fault tolerance through features like replica sets and automated failover.
- Explain the concept of sharding in MongoDB.
Sharding is the process of distributing data across multiple machines to improve horizontal scalability. It allows MongoDB to handle large datasets by splitting them into smaller, more manageable pieces.
- What is an ObjectId in MongoDB, and how is it generated?
ObjectId is a 12-byte identifier used in MongoDB documents to uniquely identify them. It consists of a timestamp, machine identifier, process identifier, and a counter.
- What is indexing in MongoDB, and why is it important?
Indexing in MongoDB is the process of creating indexes on specific fields to improve query performance. It helps in faster data retrieval and sorting.
- What is Map-Reduce in MongoDB, and when would you use it?
Map-Reduce is a data processing technique in MongoDB that allows you to process and analyze large datasets. It’s used for complex data aggregation and analytics.
- How can you perform aggregation in MongoDB?
MongoDB provides the Aggregation Framework for performing data aggregation operations. It includes various stages like `$match`, `$group`, `$project`, and more.
- What are the different write concerns in MongoDB, and when would you use them?
Write concerns in MongoDB define the acknowledgment level required for write operations. The most common levels are “acknowledged,” “w1,” and “majority.” The choice depends on your data durability requirements.