React JS:
React js is a popular JavaScript library used for building user interfaces (UIs) for web applications. Developed by Facebook, React allows developers to create reusable UI components that can efficiently update and render data changes. It employs a declarative approach, where developers describe how the UI should look based on the application's state. React takes care of updating and rendering the components when the state changes. React's virtual DOM (Document Object Model) makes this process efficient by only updating the parts of the UI that have changed, resulting in better performance and a smoother user experience.
Why Choose React JS:
Declarative grammar: React employs declarative grammar, making it easier to understand and create code. Developers can specify how the UI should look based on the current application state, and React updates the DOM to match that state.
Component-Based Architecture: React advocates a modular approach to designing UIs through its component-based architecture. This lets developers split down large UIs into smaller, reusable components, making code more organized and maintainable.
Virtual DOM: React utilizes a virtual DOM, a lightweight version of the actual DOM. When a component's state changes, React compares the virtual DOM to the previous version, determines the most effective way to update the actual DOM, and applies the changes. This leads to higher performance compared to manually manipulating the DOM.
JSX: JSX is a syntactic extension for JavaScript that enables developers to construct HTML-like code within JavaScript. This makes it easy to write and reason about UI components since they approximate the final output structure.
One-Way Data Binding: React enforces unidirectional data flow, which means that data travels from parent to child components. This makes it easier to understand how data moves across the program and helps to prevent common data mutability errors.
Rich Ecosystem and Community Support: React includes a large ecosystem of libraries, tools, and community support, making it easier for developers to solve common challenges and accelerate development.
Performance: React's virtual DOM and rapid reconciliation mechanism contribute to its excellent performance, making it perfect for developing quickly.
Backed by Facebook: React is maintained by Facebook, which means it benefits from regular updates, improvements, and ongoing support from a large team of developers.
Components in React :
In React, components serve as the foundation for user interfaces. They are reusable, stand-alone bits of code that provide specific functionality and/or user interface features. There are two major types of components in React:
1. Functional Components: These are simple JavaScript functions that accept props (short for properties) as arguments and return React components that specify what should be displayed on the screen. Functional components are commonly utilized to show UI elements and are preferred for their simplicity and performance.
2. Class Components: Class components are ES6 classes derived from React.Component. They offer a more feature-rich API than functional components and can store state, manage lifecycle methods, and handle complicated logic.
Components can be nested within each other to create complex UI structures. They promote reusability, maintainability, and composability, making it easier to manage large-scale applications by breaking them down into smaller pieces.
Types of Components in React:
Components in React are divided into two major categories they are Functional & class components.
Functional Components:
These are simple JavaScript functions that accept props (properties) as input and return React elements.
Functional components are stateless, which means they do not maintain their own state or lifecycle methods.
They are generally used to display UI elements and perform basic logic.
With the introduction of React Hooks, functional components can now use state and lifecycle methods via hooks such as useState and useEffect.Class Components:
Class components are ES6 classes that extend React. Component.
They offer a more feature-rich API than functional components.
Class components can store and maintain their own information, perform lifecycle operations such as componentDidMount and componentDidUpdate, and encapsulate more complicated functionality.
However, with the introduction of React Hooks, many of the functionality of class components can now be performed in functional components, making functional components the preferred choice in many circumstances due to their simplicity and performance benefits.Difference Between Functional & Class Components:
Functional components and class components are two types of components used in React for building user interfaces. Here are the key differences between them:
Syntax:
Functional components are simple JavaScript functions that take props as input and return React elements.
Class components are ES6 classes that extend from React.Component and have a render method that returns React elements.
State Management:
Functional components were initially stateless, meaning they couldn't manage their own state. However, with the introduction of hooks in React 16.8, functional components gained the ability to use state and other features previously exclusive to class components. useState and useEffect are examples of hooks used for state management and side effects, respectively.
Class components have built-in state management using this.state and this.setState(). They can hold local component state and manage it throughout the component lifecycle.
Lifecycle Methods:
Functional components don't have lifecycle methods. However, with the introduction of useEffect hook, functional components can now perform side effects and mimic some of the behavior of lifecycle methods like componentDidMount, componentDidUpdate, and componentWillUnmount.
Class components have access to lifecycle methods like componentDidMount, componentDidUpdate, componentWillUnmount, etc., allowing developers to perform certain actions at specific points in the component's lifecycle.
Performance:
Functional components are generally considered more lightweight and performant because they are just plain JavaScript functions.
Class components, on the other hand, might have a slightly higher overhead due to their reliance on ES6 classes and the additional features they provide.
Readability and Syntax:
Functional components are often considered more concise and easier to read, especially for simpler UI components.
Class components, while more verbose due to their class syntax, might be preferred for more complex components that require local state or lifecycle methods.
In summary, while functional components are becoming increasingly popular due to their simplicity and performance, class components still have their place, especially in legacy codebases or when working with complex state management and lifecycle requirements.
Hope you find some useful content about React JS & it's life cycle components. For more details regarding demo Session get in touch with us at Mob: +91 84660 44555.