Questions related to React JS, optimization techniques, core web vitals, and webpack.

• React JS life cycle methods include componentDidMount, componentDidUpdate, and componentWillUnmount.

• Context API is used for sharing data between components without passing props down the component tree.

• Advantages of Context API include avoiding prop drilling and making it easier to manage global state.

• Disadvantages of Context API include potential performance issues and difficulty with testin...read more

To check/uncheck checkbox by clicking on label, use 'for' attribute and 'id' of checkbox.

• Add 'for' attribute to label with value equal to 'id' of checkbox

• Add 'id' attribute to checkbox

• Clicking on label will toggle checkbox state

No, media queries are necessary for responsive design.

• Media queries are used to apply different styles based on screen size

• Without media queries, the design would not adapt to different devices

• Responsive design is essential for a good user experience

Use CSS variables to define colors and switch between themes based on user preference.

• Define CSS variables for light and dark theme colors

• Use JavaScript to detect user preference for light or dark theme

• Switch between themes by updating CSS variables with JavaScript

• Consider using a toggle button or system preference to allow users to switch themes manually

Event loop is a mechanism in JavaScript that handles asynchronous operations.

• JavaScript is a single-threaded language, meaning it can only execute one task at a time.

• Asynchronous programming allows multiple tasks to be executed simultaneously.

• Event loop is responsible for managing the execution of asynchronous code.

• Callbacks, Promises, and Async/Await are common ways to handle asynchronous code in JavaScript.

A webpage can be made responsive by using media queries, flexible grids, and images, and by optimizing the layout for different devices.

• Use CSS media queries to adjust the layout based on screen size

• Use flexible grids and images that can scale to fit different screen sizes

• Optimize the layout for touch devices by using larger buttons and spacing

• Test the responsiveness on different devices and adjust as needed

Tags are used to define the start and end of an element in HTML.

• Tags are enclosed in angle brackets, like .

• Elements are made up of tags, attributes, and content.

• Tags define the structure of the content, while elements define the meaning.

• Examples of tags include

  ,

  , , while examples of elements include

  ,

Mixin is a reusable block of code in SCSS that can be included in other stylesheets.

• Mixin allows developers to define a set of CSS declarations that can be reused throughout the stylesheet.

• It helps in reducing code duplication and makes the code more maintainable.

• Mixin can take arguments and can be used to generate different styles based on the arguments passed.

• Mixin can be defined using the @mixin directive and included using the @include directive.

Flexbox is one-dimensional layout while Grid is two-dimensional layout.

• Flexbox is best suited for arranging items in a single row or column.

• Grid is best suited for arranging items in rows and columns.

• Flexbox has a main axis and a cross axis.

• Grid has rows and columns that intersect to form grid cells.

• Flexbox is great for responsive design and centering items.

• Grid is great for complex layouts and aligning items precisely.

• Flexbox is supported by all modern browsers.

• Grid is suppo...read more

SCSS is used to write more maintainable and scalable CSS code.

• SCSS allows for nesting of CSS rules, making it easier to read and organize code.

• Variables and mixins in SCSS can be reused throughout the codebase, reducing redundancy.

• SCSS also supports inheritance, allowing for more efficient and modular code.

• It compiles to regular CSS, so it can be used in any web project.

• SCSS is widely used in modern web development frameworks like React and Angular.

SCSS provides benefits like variables, nesting, mixins, and inheritance to make CSS more efficient and maintainable.

• SCSS allows for the use of variables, which can be reused throughout the stylesheet.

• Nesting in SCSS makes it easier to read and organize code.

• Mixins allow for the reuse of code snippets, reducing the amount of code needed.

• Inheritance in SCSS allows for the creation of base styles that can be extended and modified as needed.

• SCSS also provides functions and operat...read more

Box model is a fundamental concept in CSS that defines how elements are rendered on a web page.

• Box model consists of content, padding, border, and margin.

• Content is the actual content of the element.

• Padding is the space between the content and the border.

• Border is the line that surrounds the element.

• Margin is the space between the border and the adjacent elements.

• Box-sizing property can be used to change the box model behavior.

• Default box-sizing value is content-box.

• border-bo...read more

Context API is a feature in React that allows sharing data between components without having to pass props through every level of the component tree.

• Context API provides a way to pass data through the component tree without having to pass props down manually at every level.

• It is useful for sharing global data such as themes, user authentication, or language preferences.

• Context API consists of three main parts: Provider, Consumer, and useContext hook.

• Example: createContext() c...read more

Browser storages are used to store data locally on the user's browser.

• Browser storages include cookies, local storage, and session storage.

• Cookies are used to store small amounts of data that can be accessed by the server or client-side scripts.

• Local storage and session storage are used to store larger amounts of data that can only be accessed by client-side scripts.

• Browser storages can be used to improve user experience by storing user preferences and login information.

• Howev...read more

Hooks in React JS are functions that let you use state and other React features without writing a class.

• Hooks were introduced in React 16.8 to allow functional components to have state and lifecycle methods.

• useState() is a hook that allows you to add state to functional components.

• useEffect() is a hook that allows you to perform side effects in functional components.

• Custom hooks are reusable functions that can contain logic and stateful logic for components.

• Hooks provide a mo...read more