{"id":32869,"date":"2024-11-01T09:12:06","date_gmt":"2024-11-01T09:12:06","guid":{"rendered":"http:\/\/atmokpo.com\/w\/?p=32869"},"modified":"2024-11-01T11:21:40","modified_gmt":"2024-11-01T11:21:40","slug":"react-course-how-react-apps-work","status":"publish","type":"post","link":"https:\/\/atmokpo.com\/w\/32869\/","title":{"rendered":"React Course: How React Apps Work"},"content":{"rendered":"

<\/p>\n

React is a JavaScript library developed by Facebook, optimized for building user interfaces. It is primarily used for developing single-page applications (SPAs) and allows for efficient work with reusable UI components. In this course, I will explain in detail how React apps work.<\/p>\n

1. What is React?<\/h2>\n

React is a component-based library designed to simplify the construction of complex applications. The core idea of React is to create “components,” small abstract entities that make up the UI.<\/p>\n

2. Basic Concepts of React<\/h2>\n

2.1. Components<\/h3>\n

Components are independent pieces that make up the UI as part of React. Each component can have its own state and properties, allowing them to perform various actions.<\/p>\n

2.2. State and Props<\/h3>\n

React builds dynamic UIs through a component’s “state” and “props.” The state is managed within the component and changes according to user interactions. In contrast, props are the data passed from a parent component to a child component.<\/p>\n

3. Structure of a React App<\/h2>\n

A React application consists of multiple components. Each component can contain other components, enabling the construction of complex UIs. Typically, a single root component encompasses all child components.<\/p>\n

3.1. Example Structure<\/h3>\n
\n\/App\n  \u251c\u2500 \/Header\n  \u251c\u2500 \/Main\n  \u2502   \u251c\u2500 \/Sidebar\n  \u2502   \u2514\u2500 \/Content\n  \u2514\u2500 \/Footer\n    <\/code><\/pre>\n
4. How React Apps Work<\/h2>\n
4.1. DOM and Virtual DOM<\/h3>\n
One of the most significant features of React is the concept of “Virtual DOM.” React uses Virtual DOM to optimize performance rather than directly accessing the real DOM. The Virtual DOM is a virtual representation of the DOM structure in memory, comparing differences with the actual DOM to minimize updates.<\/p>\n
4.2. Process of Operation<\/h3>\n
    \n
  1. When a React component is rendered, a Virtual DOM is created.<\/li>\n
  2. When the state changes, a new Virtual DOM is generated.<\/li>\n
  3. Previous and new Virtual DOMs are compared (diffing).<\/li>\n
  4. Only the changed parts are updated in the real DOM.<\/li>\n<\/ol>\n
    4.3. Example Code<\/h3>\n
    \nimport React, { useState } from 'react';\n\nfunction Counter() {\n    const [count, setCount] = useState(0);\n\n    const increment = () => {\n        setCount(count + 1);\n    };\n\n    return (\n        
    \n            
    Current Count: {count}<\/h1>\n