https://zh-hans.react.dev/learn/tutorial-tic-tac-toe
App.js 的代码创建了一个 组件。在 React 中，组件是一段可重用代码，它通常作为 UI 界面的一部分。组件用于渲染、管理和更新应用中的 UI 元素。让我们逐行查看这段代码，看看发生了什么： /The code in App.js creates a component. In React, a component is a piece of reusable code that represents a part of a user interface. Components are used to render, manage, and update the UI elements in your application. Let’s look at the component line by line to see what’s going on:
export default function Square() { return X; }
The code in App.js creates a component. In React, a component is a piece of reusable code that represents a part of a user interface. Components are used to render, manage, and update the UI elements in your application. Let's look at the component line by line to see what's going on: // The first line defines a function called Square. The export JavaScript keyword makes this function accessible outside of this file. The default keyword tells other files using your code that it’s the main function in your file.
The first line defines a function called Square.The export JavaScript keyword makes this function accessible outside of this file. The default keyword tells other files using your code that it's the main function in your file.