10+ DCM Shriram Interview Questions and Answers

useEffect can mimic lifecycle methods by specifying dependencies and cleanup functions.

• useEffect can be used to mimic componentDidMount by specifying an empty dependency array.

• useEffect can be used to mimic componentDidUpdate by specifying a dependency array.

• useEffect can be used to mimic componentWillUnmount by returning a cleanup function.

• useEffect can be used to mimic shouldComponentUpdate by using memoization techniques.

• useEffect can be used to mimic componentDidCatch by ...read more

To update state in React components, use setState() method.

• Use setState() method to update state

• Pass an object with updated state values to setState()

• setState() is asynchronous, so use callback function to perform actions after state update

• Avoid directly modifying state using this.state

• Example: this.setState({ count: this.state.count + 1 }, () => console.log('State updated'))

State and Props are two important concepts in React for managing data and passing data between components.

• State is an object that holds data that can change over time within a component.

• Props are read-only data that are passed from a parent component to a child component.

• State can be updated using setState() method.

• Props can be accessed using this.props.

• State is used for managing component's internal state while props are used for passing data between components.

• Example:

• Exam...read more

Hooks are a feature in React that allow for stateful logic to be used in functional components.

• Hooks allow for reusable logic to be extracted from components

• They simplify code and reduce the need for class components

• useState hook allows for state management in functional components

• useEffect hook allows for side effects to be performed in functional components

• useContext hook allows for easy access to context in functional components

Components can be created as classes or functions in React JS.

• Class components are created using ES6 classes and have a state and lifecycle methods.

• Function components are created using functions and do not have a state or lifecycle methods.

• Hooks can be used in function components to add state and lifecycle functionality.

• Components can be reused throughout the application.

• Examples: Class component - class MyComponent extends React.Component {} Function component - function My...read more

Yes, I have experience in coding optimization to improve performance and efficiency.

• Identifying and removing unnecessary code or dependencies

• Minifying and compressing code for faster loading times

• Using efficient algorithms and data structures

• Reducing the number of API calls by batching requests

• Implementing lazy loading for resources to improve page load times

Debugger in JavaScript is used for pausing the execution of code to inspect variables, check the flow of the program, and debug errors.

• Debugger helps in identifying and fixing bugs in the code.

• It allows developers to step through code line by line to understand the flow of execution.

• Developers can inspect variables and their values at different points in the code.

• By setting breakpoints, developers can pause the code at specific locations to analyze the state of the applicatio...read more

JSX is a syntax extension for JavaScript used in React to write HTML-like code in JavaScript.

• JSX allows developers to write HTML-like code in JavaScript

• It is not a separate language, but a syntax extension for JavaScript

• JSX code is compiled into JavaScript code by Babel

• JSX expressions must have a single parent element

• JSX expressions can include JavaScript expressions using curly braces {}

Conditional rendering in React allows components to render different elements or components based on certain conditions.

• Use ternary operator to conditionally render elements

• Use logical && operator for conditional rendering

• Use if-else statements inside render method for more complex conditions

Global state management is a way to manage and share state data across multiple components in a React application.

• It helps in avoiding prop drilling by providing a centralized location for storing and updating state.

• Common libraries for global state management in React include Redux, Context API, and MobX.

• Global state management allows for easier state synchronization between components and can improve performance.

• Example: Redux allows you to create a global store to hold app...read more

Arrow functions are a concise way to write functions in JavaScript.

• Arrow functions do not have their own 'this' keyword.

• Arrow functions are more concise than traditional function expressions.

• Arrow functions do not have their own 'arguments' object.

• Arrow functions are best suited for non-method functions.

• Example: const add = (a, b) => a + b;

React is a JavaScript library for building user interfaces.

• React allows for the creation of reusable UI components

• It uses a virtual DOM for efficient rendering

• React makes it easier to manage state and data flow in applications

Lazy loading is a technique used in web development to defer loading non-essential resources until they are needed.

• Lazy loading helps improve page load times by only loading resources when they are required.

• It is commonly used for images, videos, and other media files on websites.

• Lazy loading can be implemented using libraries like React.lazy() in React.js.

JSX is a syntax extension for JavaScript that allows HTML to be written in React components. ES6 is a newer version of JavaScript with additional features.

• JSX allows developers to write HTML-like code within JavaScript files

• ES6 introduces new syntax and features like arrow functions, classes, and template literals

• JSX is transformed into regular JavaScript by tools like Babel before being rendered in the browser