ReactJS Tutorial - 8 - JSX JSX in React: Exam Notes What is JSX? - An extension to JavaScript syntax used with React. Allows writing XML-like code for elements and components. JSX tags have tag names, attributes, and children. Why use JSX? - Not strictly necessary for React, but simplifies and makes code more elegant. Provides a familiar syntax for many developers. Ultimately translates to pure JavaScript understood by browsers. JSX vs. React.createElement() - JSX Example: React.createElement() Example: - React.createElement() requires explicit specification of tags, attributes, and children. It's more verbose than JSX. JSX is syntactic sugar for React.createElement() . This is why you need to import react when using JSX. JSX Attributes: - Attributes are passed as key-value pairs in an object. className instead of class (class is a reserved word in JavaScript). Camel case for attribute names (e.g., onClick , tabIndex ). Differences between JSX and HTML: - HTML JSX class className for htmlFor onclick onClick Breaking Changes in React (Future): - Check the link in the video description for updates. Potential change: className might become class in future React versions (18 or 19). Likely Exam Questions: Explain the purpose and benefits of using JSX in React applications. Compare and contrast the use of JSX with the React.createElement() method. Provide examples. How do you handle attributes like class and for in JSX? Explain the naming conventions. Describe the potential breaking changes proposed for future React versions concerning JSX. Write a simple React component using JSX that renders a paragraph with a specific class and an onClick handler. Then, rewrite the same component using React.createElement() . Recap: JSX simplifies React development by providing a concise and familiar syntax for creating UI elements. It translates to React.createElement() calls under the hood. Understanding the differences between JSX and standard HTML attributes is crucial for writing correct and efficient React code. Be aware of potential future breaking changes in React related to JSX. ReactJS Tutorial - 8 - JSX JSX in React: A Deep Dive This blog post summarizes a video explaining JSX, its purpose, functionality, and differences from standard HTML. We'll explore JSX's role in simplifying React code and see how it translates to pure JavaScript. What is JSX? - JSX (JavaScript XML) is an extension to the JavaScript syntax used with the React library . - It allows writing XML-like code for elements and components . - JSX tags have tag names, attributes, and children , similar to XML. - While not strictly necessary for React development, JSX significantly improves code simplicity and elegance . - JSX ultimately compiles to pure JavaScript understandable by browsers. - JSX vs. React.createElement() - To illustrate JSX's functionality, the video contrasts creating a simple React component with and without JSX. JSX Example - A functional component ( hello.js ) rendering "Hello Vishwas": Without JSX - The equivalent component without JSX uses React.createElement() : This example highlights the verbosity of React.createElement() . Note the need for multiple calls to handle nested elements and attributes. The second parameter of React.createElement() is an object for attributes. className must be used instead of class to avoid conflicts with JavaScript's reserved keyword. Feature JSX React.createElement() Syntax Concise, HTML-like Verbose, programmatic Readability High Low, especially with nested elements Maintainability Easier More difficult with complex components Attribute names className , onClick className , onClick (camelCase required) JSX and HTML Differences - Key differences between JSX and standard HTML: class vs. className : JSX uses className for CSS classes. for vs. htmlFor : JSX uses htmlFor for the for attribute in <label> elements. Camel Case : JSX uses camel case for event handlers (e.g., onClick ) and other attributes. Future Changes in React - The React team is planning breaking changes (potentially in React 18 or 19), including possibly reverting className back to class . A link to relevant information is provided in the original video description. Summary JSX simplifies React development by providing a more intuitive and readable syntax for creating UI elements. While it compiles to standard JavaScript, understanding its underlying mechanism (using React.createElement() ) provides valuable insights into React's rendering process. Being aware of the differences between JSX and HTML, and keeping an eye on planned updates, is crucial for writing maintainable and future-proof React code. sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss1sssssssssssssss Prop drilling is a fundamental concept in React for managing and sharing data across components. Understanding Prop Drilling in React Prop drilling refers to the process of passing data (known as "props," short for properties) from a parent component down through multiple layers of child components to reach a deeply nested component that requires that data. Props hold data and allow information to flow unidirectionally from a parent to its children. When a component needs data that is held by a distant ancestor, the data must be explicitly passed down through all intermediate components, even if those components do not directly use the data themselves. ( , ) For instance, if a parent component Content.js holds data like items , handleCheck , and handleDelete , these are passed down as props to its child, such as an unordered list, and then potentially further down to individual list items. This continuous passing down through the hierarchy is the essence of prop drilling. ( , , , ) Prop Drilling for Sibling Component Data Sharing Sibling components in React cannot directly communicate or share data with each other. For two sibling components to share data, the data must be managed by their closest common parent component. Once the data resides in the common parent's state, prop drilling is then utilized. The common parent passes the necessary data as props down to each of its children (the sibling components) that require access to that data. For example, if a Footer component needs to display a count of items that are stored in a Content component, and Footer and Content are siblings, the item data cannot be directly accessed. Instead, the data would be held in their common parent component (e.g., App.js ), and then that parent would drill the items (or their count) down to the Footer component via props. ( , , , ) While effective, extensive prop drilling can make the codebase more cumbersome to maintain and understand, as many components may receive props that are irrelevant to their direct functionality. ( , ) Would you like to explore how prop destructuring can make working with props more efficient within a component?