Introduction to React
React is a JavaScript library for building user interfaces. It was developed by Facebook, and it's used to create interactive web pages that can be updated in real-time.
React has several benefits over other frameworks:
It uses a component-based architecture, which makes it easy to develop large applications with complex views.
The virtual DOM makes React apps fast because they only update the parts of the page that need updating when something changes (e.g. if you click on a button). This also means that you don't have to worry about browser compatibility issues when using React (since it doesn't use any browser hacks).
Setting up a React Environment
To get started with React, you'll need to install Node.js and create a development environment.
Install Node.js
If you don't already have it installed on your computer, visit https://nodejs.org/en/download/ and follow the instructions for installing it on your system (it's usually as simple as double-clicking on an installer file).Set up the React development environment
Once you've installed Node, open up a terminal window in Mac OS or Linux by pressing Command + Spacebar, typing Terminal, then press Enter. In Windows 10 (or 7), press Win + R, type cmd into the Run dialog box that appears at the top left corner of the screen; then press Enter. In either case: once inside your command line interface (CLI), run these commands in order: cd ~ && mkdir react && cd react && npm install -g create-react-app@latest --yes
Components and Props
Components are the building blocks of a React application. They're reusable, composable and can be used to build more complex components. A component consists of three parts:
The render method, which returns HTML markup
The state, which stores data and is updated when you make changes to it
A set of props (properties), which are passed into the component from its parent or grandparent components
State and Lifecycle
Understanding state and lifecycle
The state is a key concept in React. It's a way of storing data that can be accessed by your components, and it's stored in the form of an object. You can think of the state as being similar to an instance variable in other programming languages; it's something you can access from inside your functions or methods, but not outside them.
When you're working with React, there are two main types of state: local and global (or "application"). The local state lives within individual components; it doesn't get passed down through child components or affect any other parts of your app beyond its immediate scope. Global application state is shared across multiple components--it might be used for things like showing/hiding models or changing what content appears on each page load
Routing
Routing is a way to navigate from one page or screen to another. In most web applications, users can click links and buttons to move between pages. Routing allows you to define these actions as well as create custom routes that don't follow the traditional URL structure.
In this section, we'll cover how routing works in React apps and how to set up routes using React Router (a popular library for managing routes).
Styling Components
Styling components is one of the most important parts of front-end development with React. If you've worked with CSS before, you may be used to styling individual elements or groups of elements by applying classes and IDs. However, this approach doesn't work well with React because it makes it difficult for us to create reusable components that can be styled independently from each other.
For us to style our components in a way that allows them to be reused easily, we need an approach where we can apply styles directly on top of our component's HTML element itself. This is called "inlining" styles because they're written inside your JSX code (the XML-like syntax used by React). Inline styles are generally frowned upon by experienced developers because they make debugging harder since there's no separation between presentation and behavior anymore; however, since we're dealing only with simple components here I think it'll work fine!