diff --git a/article/2023/44-react-frontend-interview-questions.md b/article/2023/44-react-frontend-interview-questions.md index 47682f32998..7f65be25892 100644 --- a/article/2023/44-react-frontend-interview-questions.md +++ b/article/2023/44-react-frontend-interview-questions.md @@ -1,44 +1,44 @@ -> * 原文地址:[44 React Frontend Interview Questions](https://dev.to/m_midas/44-react-frontend-interview-questions-2o63) +> * 原文地址:[44道 React 前端面试题](https://dev.to/m_midas/44-react-frontend-interview-questions-2o63) > * 原文作者:[TYan Levin](https://dev.to/m_midas) > * 译文出自:[掘金翻译计划](https://github.com/xitu/gold-miner) > * 本文永久链接:[https://github.com/xitu/gold-miner/blob/master/article/2023/44-react-frontend-interview-questions.md](https://github.com/xitu/gold-miner/blob/master/article/2023/44-react-frontend-interview-questions.md) -> * 译者: +> * 译者:missop > * 校对者: -## Introduction +## 介绍 -When it comes to interviewing for a React frontend developer position, being well-prepared for the technical questions is crucial. React has become one of the most popular JavaScript libraries for building user interfaces, and employers often focus on assessing a candidate's understanding of React's core concepts, best practices, and related technologies. In this article, we will explore a comprehensive list of questions commonly asked during React frontend developer interviews. By familiarizing yourself with these questions and their answers, you can enhance your chances of success and demonstrate your proficiency in React development. So, let's dive in and explore the key topics that you should be ready to tackle in a React Frontend Developer interview. +在面试 React 前端开发之前,为技术问题做好充分准备是至关重要的。React 已经成为最流行的用于构建用户界面的 JavaScript 库之一,并且雇主比较热衷于评估应聘者对 React 的核心概念、最佳实践和相关技术的理解程度。在这篇文章中,我们将探讨一下React 前端开发面试中涉及到的一系列问题。通过了解这些问题的答案,你可以提高你面试成功的次数,并展现你在 React 开发中的熟练程度。因此,让我们深入探讨一下你在 React 前端开发面试中应该准备好的题目。 ![](https://i.giphy.com/media/AYECTMLNS4o67dCoeY/giphy.gif) -### 1. What React hooks do you know? +### 1. 你知道那些 React 钩子? -- `useState`: Used for managing state in functional components. -- `useEffect`: Used for performing side effects in functional components, such as fetching data or subscribing to events. -- `useContext`: Used for accessing the value of a React context within a functional component. -- `useRef`: Used for creating mutable references to elements or values that persist across renders. -- `useCallback`: Used for memoizing functions to prevent unnecessary re-renders. -- `useMemo`: Used for memoizing values to improve performance by caching expensive computations. -- `useReducer`: Used for managing state with a reducer function, similar to how Redux works. -- `useLayoutEffect`: Similar to useEffect, but the effect runs synchronously after all DOM mutations. +- `useState`: 管理函数组件中的状态。 +- `useEffect`: 在函数组件中执行副作用,例如获取数据或订阅事件。 +- `useContext`: 访问函数组件中的 React 上下文的值。 +- `useRef`: 创建渲染过程持久存在的元素或者值的可变的引用。 +- `useCallback`: 缓存函数以防止不必要的重新渲染。 +- `useMemo`: 缓存值,通过缓存昂贵的计算结果来提高性能。 +- `useReducer`: 使用 reducer 函数管理状态,类似于 Redux 的工作方式。 +- `useLayoutEffect`: 类似于 useEffect,但是在所有 DOM 更新之后会同步执行副作用函数。 -These hooks provide powerful tools for managing state, handling side effects, and reusing logic in React functional components. +这些钩子为 React 函数组件提供了强有力的工具,用来管理状态、处理副作用和复用逻辑。 -[Learn more](https://react.dev/reference/react) +[了解更多](https://react.dev/reference/react) -### 2. What is Virtual DOM? +### 2. 什么是虚拟 DOM? -Virtual DOM is a concept in React where a lightweight, virtual representation of the actual DOM (Document Object Model) is created and stored in memory. It is a programming technique used to optimize the performance of web applications. +虚拟 DOM 是 React 中的一个概念,它存储在内存中,并且可以更加轻量地表达真实的 DOM 结构(文档对象模型)。它是一种用于优化 Web 应用程序性能的编程技术。 -When changes are made to the data or state of a React component, the virtual DOM is updated instead of directly manipulating the real DOM. The virtual DOM then calculates the difference between the previous and updated state of the component, known as the "diffing" process. +对 React 组件的数据或状态进行更改之后,React 将更新虚拟 DOM,而不是直接操作真实的 DOM。然后,虚拟 DOM 会对比组件的旧状态和新状态之间的差异,这就是我们熟知的`diff`过程。 -Once the differences are identified, React efficiently updates only the necessary parts of the real DOM to reflect the changes. This approach minimizes the number of actual DOM manipulations and improves the overall performance of the application. +一旦对比出差异之后,React 就会高效地更新 DOM 实际发生改变的部分。这种方法将 DOM 操作的次数降到了最少,提高了应用程序的整体性能。 -By using the virtual DOM, React provides a way to create dynamic and interactive user interfaces while ensuring optimal efficiency and rendering speed. +通过使用虚拟 DOM,React 提供了一种创建动态和交互式用户界面的方法,同时确保了最佳的效率和渲染速度。 -### 3. How to render an array of elements? +### 3. 怎么渲染数组类型的元素? -To render an array of elements, you can use the `map()` method to iterate over the array and return a new array of React elements. +要渲染一个数组类型的元素,你可以使用 `map()` 方法遍历数组并返回一个新数组,在这个新数组中每一项都是一个 React 元素。 ```tsx const languages = [ @@ -56,13 +56,13 @@ function App() { } ``` -[Learn more](https://react.dev/learn/rendering-lists) +[了解更多](https://react.dev/learn/rendering-lists) -### 4. What is the difference between controlled and uncontrolled components? +### 4. 受控组件与非受控组件有什么区别? -The difference between controlled and uncontrolled components lies in **how they manage and update their state**. +受控组件和非受控组件之间的区别在于它们如何管理和更新状态。 -Controlled components are components where the state is controlled by React. The component receives its current value and updates it through props. It also triggers a callback function when the value changes. This means that the component doesn't store its own internal state. Instead, the parent component manages and passes the value down to the controlled component. +受控组件的状态由 React 控制。组件接收最新的状态值并通过 props 进行更新。当值更改时,它还会触发一个回调函数。这意味着组件不存储它自己的内部状态,而是交给父组件管理状态,然后父组件将最新的状态值其传递给受控组件。 ```tsx import { useState } from 'react'; @@ -80,7 +80,7 @@ function App() { } ``` -Uncontrolled components, on the other hand, manage their own state internally using refs or other methods. They store and update their state independently, without relying on props or callbacks. The parent component has less control over the state of uncontrolled components. +另一方面,非受控组件通过引用或其他方法在内部管理自己的状态。它们独立存储和更新状态,不依赖于 props 或回调。父组件对非受控组件的状态的控制较少。 ```tsx import { useRef } from 'react'; @@ -99,13 +99,13 @@ function App() { ``` -[Learn more](https://react.dev/learn/sharing-state-between-components#controlled-and-uncontrolled-components) +[了解更多](https://react.dev/learn/sharing-state-between-components#controlled-and-uncontrolled-components) -### 5. What is the difference between class-based and functional React components? +### 5. 类组件和函数组件的区别? -The main difference between class-based and functional components is **how they are defined and the syntax they use.** +类组件和函数组件的主要区别在于 **声明它们的方式以及它们的语法**。 -Class-based components are defined as ES6 classes and extend the `React.Component` class. They use the `render` method to return the JSX (JavaScript XML) that defines the component's output. Class components have access to component lifecycle methods and state management through `this.state` and `this.setState()`. +类组件由 ES6 中的类构造出来,并继承了`React.Component` 类。他们使用`render`方法 来返回定义了组件输出的 JSX (JavaScript XML)。类组件可以通过`this.state`和`this.setState()`访问组件生命周期方法和状态管理。 ```tsx class App extends React.Component { @@ -132,7 +132,7 @@ class App extends React.Component { } ``` -Functional components, on the other hand, are defined as simple JavaScript functions. They take in props as arguments and return JSX directly. Functional components do not have access to lifecycle methods or state. However, with the introduction of React Hooks in React 16.8, functional components can now manage state and use other features such as context and effects. +与类组件不同的是,函数组件由简单的 JavaScript 函数定义。它们以参数形式接收 props,并直接返回 JSX。函数式组件不能访问生命周期方法或者状态。但是,随着 React 16.8 中引入的 React Hooks,函数式组件现在可以管理状态,并使用诸如 context 和 effects 等特性 ```tsx import { useState } from 'react'; @@ -155,46 +155,46 @@ const App = () => { } ``` -In general, functional components are considered simpler and easier to read and test. It is recommended to use functional components whenever possible, unless there is a specific need for class-based components. +总体上来说,函数式组件比类组件更简单,更容易阅读和测试。除非有特定需要,否则建议尽可能使用函数式组件。 -### 6. What are the lifecycle methods of a component? +### 6. 组件有哪些生命周期? -Lifecycle methods are a way to hook into the different stages of a component's life cycle, allowing you to execute specific code at specific times. +生命周期方法是一种连接到组件生命周期的不同阶段的方法,允许你在特定的时间执行特定的代码。 -Here is the list of the major lifecycle methods: +下面是主要的生命周期方法列表: -1. `constructor`: This is the first method called when a component is created. It is used for initializing state and binding event handlers. In functional components, you would use the `useState` hook for similar purposes. +1. `constructor`: 这是在创建组件时调用的第一个方法。它用于初始化状态和绑定事件处理程序。在函数组件中,可以使用`useState`钩子来实现类似的目的。 -2. `render`: This method is responsible for rendering JSX markup and returns the content to be displayed on the screen. +2. `render`: 这个方法负责渲染 JSX 标记,并返回要显示在屏幕上的内容。 -3. `componentDidMount`: This method is called immediately after the component is rendered in the DOM. It is commonly used for initialization tasks, such as API calls or setting up event listeners. +3. `componentDidMount`: 在 DOM 中渲染组件之后立即调用这个方法。它通常用于初始化任务,例如 API 调用或设置事件侦听器。 -4. `componentDidUpdate`: This method is invoked when the component's props or state change. It allows you to perform side effects, update the component based on the changes, or trigger additional API calls. +4. `componentDidUpdate`: 当组件的 props 或 state 发生变化时调用这个方法。它允许你执行副作用、基于数据改变更新组件或触发其他 API 调用。 -5. `componentWillUnmount`: This method is called right before the component is removed from the DOM. It is used to clean up any resources that were set up in `componentDidMount`, such as removing event listeners or canceling timers. +5. `componentWillUnmount`: 从 DOM 中卸载组件之前调用这个方法。它用于清理在`componentDidMount`中设置的所有任务,例如删除事件侦听器或取消计时器。 -Some lifecycle methods, like `componentWillMount`, `componentWillReceiveProps`, and `componentWillUpdate`, have been deprecated or replaced with alternative methods or hooks. +一些生命周期方法,比如 `componentWillMount`、`componentWillReceiveProps` 和 `componentWillUpdate`, 已经被弃用或替换为替代方法或钩子。 -As for "this," it refers to the current instance of a class component. It allows you to access properties and methods within the component. In functional components, "this" is not used as functions are not bound to a specific instance. +至于`this`,它指的是类组件的当前实例。它允许你访问组件中的属性和方法。在函数组件中,不使用`this`,因为函数不绑定到特定的实例。 -### 7. What are the peculiarities of using useState? +### 7. 如何使用 useState? -`useState` returns a state value and a function to update it. +`useState` 返回了一个状态和一个更新状态的函数。 ```ts const [value, setValue] = useState('Some state'); ``` -During the initial rendering, the returned state matches the value passed as the first argument. The `setState` function is used to update the state. It takes a new state value as a parameter and **queues a re-render of the component**. The `setState` function can also accept a callback function as a parameter, which takes the previous state value as a parameter. +在首次渲染时,组件将以 useState 第一个参数的值作为 state 返回。 `setState` 函数用于更新状态。 它接受一个新的状态值作为参数 并且 **会触发一个队列去重新渲染组件**。`setState` 函数还可以接受一个回调函数作为参数,这个回调函数以最新的 state 为参数。 -[Learn more](https://react.dev/reference/react/useState) +[了解更多](https://react.dev/reference/react/useState) -### 8. What are the peculiarities of using useEffect? +### 8. 如何使用 useEffect? -The `useEffect` hook allows you to perform side effects in a functional component. -Mutations, subscriptions, timers, logging, and other side effects are not allowed inside the main body of a functional component known as the React rendering phase. This can lead to confusing errors and inconsistencies in the user interface. -Instead, it is recommended to use useEffect. The function passed to useEffect will be executed after the render is committed to the screen, or if you pass an array of dependencies as the second parameter, the function will be called every time one of the dependencies changes. +`useEffect` 钩子允许你在函数组件中执行副作用。 +在 React 渲染阶段,在函数组件的函数体内不允许执行 Mutations、 subscriptions、 timers、 logging 或者其他副作用。这可能导致用户界面产生异常以及状态与渲染的不一致。 +这种场景下建议使用 useEffect。传递给 useEffect 的函数将在渲染更新之后执行,或者如果你将依赖项数组作为第二个参数传递,那么每当依赖项之一发生更改时,就会调用该函数。 ```ts useEffect(() => { @@ -202,12 +202,13 @@ useEffect(() => { }, []) ``` -[Learn more](https://react.dev/reference/react/useEffect) +[了解更多](https://react.dev/reference/react/useEffect) -### 9. How to track the unmounting of a functional component? +### 9. 如何追踪函数组件的卸载? -Often, `useEffect` create resources that need to be cleaned up or reset before the component leaves the screen, such as a subscription or a timer identifier. -In order to do this, the function passed to `useEffect` can return a **cleanup function**. The cleanup function is run before the component is removed from the user interface to prevent memory leaks. Additionally, if the component renders multiple times (as is usually the case), the previous effect is cleaned up before the next effect is executed. +通常,`useEffect`会创建一些任务,例如订阅或者定时器标识符,这些任务一般都会在关闭界面之后被重置或者清理掉。 +为了做到这一点,传递给 `useEffect` 的函数可以返回一个 **清理函数**。这个函数在组件卸载之前执行,以防止内存泄漏。 +此外,如果组件渲染多次(通常是这种情况),则在执行下一个副作用之前清除前一个副作用。 ```ts useEffect(() => { @@ -222,10 +223,9 @@ useEffect(() => { }) ``` -### 10. What are props in React? +### 10. React 中的 props 是什么? -Props are data that is passed to the component from the parent. Props -are read-only and cannot be changed. +Props 是从父组件传递过来的数据,它是只读的,不能在子组件内修改。 ```tsx // Parent component @@ -245,25 +245,28 @@ const Child = ({ data }) => { }; ``` -[Learn more](https://react.dev/learn/passing-props-to-a-component) +[了解更多](https://react.dev/learn/passing-props-to-a-component) -### 11. What is a state manager and which ones have you worked with or know? +### 11. 什么是状态管理,你使用过或者了解过哪些状态管理工具? -State manager is a tool or library that helps manage the state of an application. It provides a centralized store or container for storing and managing data that can be accessed and updated by different components in the application. -A state manager solves several problems. Firstly, it is a good practice to separate data and the logic related to it from components. Secondly, when using local state and passing it between components, the code can become convoluted due to the potential for deep nesting of components. By having a global store, we can access and modify data from any component. -Alongside React Context, Redux or MobX are commonly used as state management libraries. +状态管理器是帮助应用程序管理状态的工具或库。它提供了一个集中的仓库或容器,用于存储和管理应用程序中不同组件都可以访问和更新的数据。 -[Learn more](https://mobx.js.org/README.html) +状态管理器可以解决几个问题。首先,将数据和与之相关的逻辑从组件中分离出来是一个很好的做法。其次,当使用局部状态并在组件之间传递时,由于组件可能进行深度嵌套,代码可能会变得复杂。通过全局状态管理,我们可以访问和修改来自任何组件的数据。 -[Learn more](https://redux-toolkit.js.org/) +和 React Context 一样,Redux 或 MobX 也是常用状态管理库之一。 -### 12. In which cases can you use local state and when should you use global state? +[了解更多](https://mobx.js.org/README.html) -Local state is recommended to be used in cases where it is only used within one component and there are no plans to pass it to other components. Local state is also used in a component representing an individual item in a list. However, if component decomposition involves nested components with data being passed down the hierarchy, it is better to use global state. +[了解更多](https://redux-toolkit.js.org/) -### 13. What is a reducer in Redux and what parameters does it take? +### 12. 什么情况下应该使用本地状态和全局状态? -A reducer is a pure function that takes the state and action as parameters. Inside the reducer, we track the type of the received action and, depending on it, we modify the state and return a new state object. +如果状态仅仅被一个组件使用并且不会传递给其他组件,此时推荐使用本地状态。本地状态还用来渲染列表项。然而,如果组件之间的组合导致数据需要在多个嵌套组件之间传递,那么推荐使用全局状态。 + +### 13. 在 Redux 中什么是 reducer,它接收哪些参数? + +reducer是一个接收 state 和 action 作为参数的纯函数。 +在 reducer 内部,我们获取到 action 的type,根据不同的类型我们去修改 state 并返回新的 state。 ```ts export default function appReducer(state = initialState, action) { @@ -278,12 +281,11 @@ export default function appReducer(state = initialState, action) { } ``` -[Learn more](https://redux.js.org/tutorials/fundamentals/part-3-state-actions-reducers) +[了解更多](https://redux.js.org/tutorials/fundamentals/part-3-state-actions-reducers) -### 14. What is an action and how can you change the state in Redux? - -Action is a simple JavaScript object that must have a field with -a type. +### 14. 在Redux中什么是 action,如何修改 state? + +Action 是一个含有 type 属性的 js 对象 ```ts { @@ -291,9 +293,7 @@ a type. } ``` -You can also optionally add some data as **payload**. In order to -change the state, it is necessary to call the dispatch function, to which we pass -action +你还可以选择性地新增一些数据 例如 **payload**. 为了改变 state,我们必须调用 dispatch 函数,这个函数会帮助我们传递 action 对象 ```ts { @@ -302,27 +302,27 @@ action } ``` -[Learn more](https://redux.js.org/tutorials/fundamentals/part-3-state-actions-reducers) +[了解更多](https://redux.js.org/tutorials/fundamentals/part-3-state-actions-reducers) -### 15. Which pattern does Redux implement? +### 15. Redux 实现了什么模式? -Redux implements the **Flux pattern**, which is a predictable state management pattern for applications. It helps in managing the state of an application by introducing a unidirectional data flow and a centralized store for the application's state. +Redux 实现了 **Flux 模式**, 它是应用程序中的一种可预测的状态管理模式。它通过引入单向数据流和应用程序状态的集中存储来帮助管理应用程序的状态。 -[Learn more](https://www.newline.co/fullstack-react/30-days-of-react/day-18/#:~:text=Flux%20is%20a%20pattern%20for,default%20method%20for%20handling%20data.) +[了解更多](https://www.newline.co/fullstack-react/30-days-of-react/day-18/#:~:text=Flux%20is%20a%20pattern%20for,default%20method%20for%20handling%20data.) -### 16. Which pattern does Mobx implement? +### 16. Mobx 实现了什么模式? -Mobx implements the **Observer pattern**, also known as the Publish-Subscribe pattern. +Mobx 实现了 **观察者模式**, 也被称作发布订阅模式。 -[Learn more](https://www.patterns.dev/posts/observer-pattern) +[了解更多](https://www.patterns.dev/posts/observer-pattern) -### 17. What are the peculiarities of working with Mobx? +### 17. 使用Mobx有什么特点? -Mobx provides decorators like `observable` and `computed` to define observable state and reactive functions. Actions decorated with action are used to modify the state, ensuring that all changes are tracked. Mobx also offers automatic dependency tracking, different types of reactions, fine-grained control over reactivity, and seamless integration with React through the mobx-react package. Overall, Mobx simplifies state management by automating the update process based on changes in observable state. +Mobx 提供了`observable` 和 `computed` 等装饰器来定义可观察的状态和响应式函数。装饰之后的 action 被用来修改 state,以确保所有的改变都能够被追踪到。Mobx 还提供了自动追踪依赖、不同类型的响应式、对响应式的细粒度的控制,以及通过 mobx-react 库与 React 无缝集成。总的来说,Mobx 通过监听 observable state 的变化自动触发状态更新来简化状态管理。 -### 18. How to access a variable in Mobx state? +### 18. 在 Mobx 状态中如何访问一个变量? -You can access a variable in the state by using the `observable` decorator to define the variable as observable. Here's an example: +你可以使用`observable`这个装饰器将变量变为可观察状态,从而在 state 中访问这个变量。举例说明: ```ts import { observable, computed } from 'mobx'; @@ -342,18 +342,18 @@ store.myVariable = 'Hi Mobx'; console.log(store.capitalizedVariable); // Output: HI MOBX ``` -In this example, the `myVariable` is defined as an observable using the `observable` decorator. You can then access the variable using `store.myVariable`. Any changes made to `myVariable` will automatically trigger updates in dependent components or reactions. +在这个例子中, 通过`observable`装饰器,`myVariable` 被定义为可观察的变量.然后你可以通过`store.myVariable`访问这个变量。任何对`myVariable`变量的修改都会自动触发组件或者副作用的更新。 -[Learn more](https://mobx.js.org/actions.html) +[了解更多](https://mobx.js.org/actions.html) -### 19. What is the difference between Redux and Mobx? +### 19. Redux 和 Mobx有什么区别? -Redux is a simpler and more opinionated state management library that follows a strict unidirectional data flow and promotes immutability. It requires more boilerplate code and explicit updates but has excellent integration with React. -Mobx, on the other hand, provides a more flexible and intuitive API with less boilerplate code. It allows you to directly modify the state and automatically tracks changes for better performance. The choice between Redux and Mobx depends on your specific needs and preferences. +Redux 是一个更简单、更保守的状态管理库,它遵循严格的单向数据流,并提高了不可变性。它需要更多的样板代码和显式的更新,但是与 React 有很好的集成 +另一方面,Mobx 提供了一个更加灵活和直观的 API,而且样板代码更少。它允许你直接修改状态并自动跟踪更改以获得更好的性能。Redux 和 Mobx 之间的选择取决于你的具体需求和偏好。 -### 20. What is JSX? +### 20. 什么是 JSX? -By default, the following syntax is used to create elements in react. +默认情况下, 在 react 中可以用下面的语法来创建元素。 ```tsx const someElement = React.createElement( @@ -363,22 +363,21 @@ const someElement = React.createElement( ); ``` -But we are used to seeing it like this +但是我们是这样创建元素的: ```tsx const someElement = (

Some Title Value

); ``` + +这就是所谓的 jsx,它是一种语言扩展,简化了对代码和开发的理解。 -This is exactly what the markup is called jsx. This is a kind of language extension -that simplifies the perception of code and development - -[Learn more](https://react.dev/learn/writing-markup-with-jsx#jsx-putting-markup-into-javascript) +[了解更多](https://react.dev/learn/writing-markup-with-jsx#jsx-putting-markup-into-javascript) -### 21. What is props drilling? +### 21. 什么是 props drilling? -Props drilling refers to the process of passing props through multiple levels of nested components, even if some intermediate components do not directly use those props. This can lead to a complex and cumbersome code structure. +Props drilling 指的是多级嵌套的组件之间层层传递 props 的一种情况, 即使某些组件并不会直接使用这些 props。 这可能导致代码结构非常复杂和冗余。 ```tsx // Parent component @@ -407,13 +406,13 @@ const ChildB = ({ data }) => { }; ``` -In this example, the `data` prop is passed from the Parent component to ChildA, and then from ChildA to ChildB even though ChildA doesn't directly use the prop. This can become problematic when there are many levels of nesting or when the data needs to be accessed by components further down the component tree. It can make the code harder to maintain and understand. +在这个例子中,`data` prop 从 Parent 组件传递给 ChildA,然后从 ChildA 传递给 ChildB,尽管 ChildA 并没有直接使用该prop。当嵌套层次很多,或者需要在非常深的层级中访问数据时,这可能会成为问题。这会使代码更难维护和理解。 -Props drilling can be mitigated by using other patterns like context or state management libraries like Redux or MobX. These approaches allow data to be accessed by components without the need for passing props through every intermediate component. +通过使用其他模式,如context或状态管理库(如 Redux 或 MobX) ,可以减少 Props drilling。这些方法允许组件访问数据,而无需通过每个中间组件传递 props。 -### 22. How to render an element conditionally? - -You can use any conditional operators, including ternary. +### 22. 如何条件渲染? + +你可以使用任何条件操作符,包括三元表达式。 ```tsx return ( @@ -445,60 +444,57 @@ return ( ); ``` -[Learn more](https://react.dev/learn/conditional-rendering) +[了解更多](https://react.dev/learn/conditional-rendering) -### 23. What is useMemo used for and how does it work? +### 23. useMemo 用处是什么,它是如何运作的? -`useMemo` is used to cache and memorize the -result of calculations. -Pass the creating function and an array of dependencies. `useMemo` will recalculate the memoized value only when the value of any of the dependencies has changed. This optimization helps to avoid -costly calculations with each render. -With the first parameter, the function accepts a callback in which calculations are performed, and with the second an array of dependencies, the function will re-perform calculations only when at least one of the dependencies is changed. +`useMemo`被用来缓存计算结果。 +需要传递一个创建值的函数以及一个依赖数组。只有当依赖数组中的值发生变化时`useMemo`才会重新计算被缓存的数据。 +这个优化帮助 React 应用程序降低了渲染时的计算开销。 +对于第一个参数,函数接受执行计算的回调,对于第二个参数,函数接受依赖项数组,只有当至少一个依赖项被更改时,函数才会重新执行计算。 ```ts const memoValue = useMemo(() => computeFunc(paramA, paramB), [paramA, paramB]); ``` -[Learn more](https://react.dev/reference/react/useMemo) +[了解更多](https://react.dev/reference/react/useMemo) -### 24. What is useCallback used for and how does it work? +### 24. useCallback是什么,它是如何运作的? -The `useCallback` hook will return a memoized version of the callback, which changes only if the values of one of the dependencies change. -This is useful when passing callbacks to optimized child components that rely on link equality to prevent unnecessary renderings. +`useCallback`钩子会返回一个被缓存的回调函数,这个回调函数只有在依赖数组中任何一个值发生改变时才会更新。 +当需要传递给子组件函数时,使用它可以减少不必要的重新渲染。 ```ts const callbackValue = useCallback(() => computeFunc(paramA, paramB), [paramA, paramB]); ``` -[Learn more](https://react.dev/reference/react/useCallback) +[了解更多](https://react.dev/reference/react/useCallback) -### 25. What is the difference between useMemo and useCallback? +### 25. useMemo 与 useCallback有什么不同? -1. `useMemo` is used to memoize the result of a computation, while `useCallback` is used to memoize a function itself. -2. `useMemo` caches the computed value and returns it on subsequent renders if the dependencies haven't changed. -3. `useCallback` caches the function itself and returns the same instance unless the dependencies have changed. +1. `useMemo` 用来缓存计算结果, 而 `useCallback` 用来缓存函数。 +2. 如果依赖没有发生变化,`useMemo` 会缓存计算值并且在后续的渲染中都会返回这个值。 +3. 如果依赖没有发生变化,`useCallback` 会缓存这个函数,并且在后续渲染中都会返回同一个函数。 -### 26. What is React Context? +### 26. 什么是 React Context? -React Context is a feature that provides a way to pass data through the component tree without manually passing props at every level. It allows you to create a global state that can be accessed by any component within the tree, regardless of its position. Context is useful when you need to share data between multiple components that are not directly connected through props. +React Context 是一个特性,它提供了一种通过组件树传递数据的方法,而无需在每个层级手动传递 props。它允许你创建一个全局状态,该状态可以被树中的任何组件访问,而不管其位置如何。当你需要在组件之间共享数据并且这些组件无法直接通过 props 进行传递时 context 就可以派上用场了。 -The React Context API consists of three main parts: +React Context API 包括以下三个主要部分: -1. `createContext`: This function is used to create a new context object. -2. `Context.Provider`: This component is used to provide the value to the context. It wraps the components that need access to the value. -3. `Context.Consumer` or `useContext` hook: This component or hook is used to consume the value from the context. It can be used within any component within the context's provider. +1. `createContext`: 该函数用来创建一个新的 context 对象。 +2. `Context.Provider`: 该组件用来为 context 提供值。它包裹了需要访问该值的组件。 +3. `Context.Consumer` 或 `useContext` hook: 该组件或者钩子用来消费来自 context 的值。他能在任何组件中使用,只要被包裹在 context 的 provider 中。 -By using React Context, you can avoid prop drilling (passing props through multiple levels of components) and easily manage state at a higher level, making your code more organized and efficient. +通过使用 React Context,你可以避免 prop drilling(在多个层级组件之间传递 props),可以在更高层级方便地管理状态,并且可以让你的代码更有条理也更高效。 -[Learn more](https://react.dev/learn/passing-data-deeply-with-context) +[了解更多](https://react.dev/learn/passing-data-deeply-with-context) -### 27. What is useContext used for and how does it work? +### 27. useContext 的用处,它是如何运行的? -In a typical React application, data is passed from top to bottom (from parent to child component) using props. However, such a method of use may be too cumbersome for some types of props -(for example, the selected language, UI theme), which must be passed to many components in the application. The context provides a way to share such data between components without having to explicitly pass the props through -each level of the tree. -The component calling useContext will always be re-rendered when -the context value changes. If re-rendering a component is costly, you can optimize it using memoization. +在一个典型的 React 应用中,一般都是使用 props 将数据自顶向下传递(从父组件到子组件)。然而,这样的使用方法对于某些类型的props(例如,选中的语言,UI 主题)来说可能太麻烦了 +,在这些情况下props 需要在应用程序中多个组件之间传递。context 提供了一种组件树各个层级之间共享数据的方式。 +调用 useContext 的组件会在 context 值改变时重新渲染。如果重新渲染组件非常消耗性能的话你可以通过缓存值来进行优化。 ```tsx const App = () => { @@ -512,14 +508,13 @@ const App = () => { } ``` -[Learn more](https://react.dev/reference/react/useContext) - -### 28. What is useRef used for and how does it work? +[了解更多](https://react.dev/reference/react/useContext) -`useRef` returns a modifiable ref object, a property. The current of which is initialized by the passed argument. The returned object will persist for the entire lifetime of the component and will not change from render to render. -The usual use case is to access the descendant in an imperative -style. I.e. using ref, we can explicitly refer to the DOM element. +### 28. useRef 的用处,它是如何运行的? +`useRef` 返回一个可修改的 ref 对象,一个属性。其当前值由传递的参数初始化。返回的对象将在组件的整个生存期内持续存在,并且不会随着渲染的不同而改变。 +通常的案例是命令式访问子代。 +例如,使用 ref,我们可以显式地引用 DOM 元素。 ```tsx const App = () => { const inputRef = useRef(null); @@ -537,11 +532,12 @@ const App = () => { } ``` -[Learn more](https://react.dev/reference/react/useRef) +[了解更多](https://react.dev/reference/react/useRef) -### 29. What is React.memo()? +### 29. 什么是 React.memo()? -`React.memo()` is a higher—order component. If your component always renders the same thing with non-changing props, you can wrap it in a `React.memo()` call to improve performance in some cases, thereby memorizing the result. This means that React will use the result of the last render, avoiding re-rendering. `React.memo()` only affects changes to the props. If a functional component is wrapped in React.memo and uses useState, useReducer, or useContext, it will be re-rendered when the state or context changes. +`React.memo()` 是一个高阶组件。 如果你的组件不存在 props 改变的情况,并且一直渲染着相同的内容,那么某些情况下你可以用“React.memo()“去包裹该组件以缓存结果,从而提升性能。 +这意味着 React 将会复用上一次 渲染 的结果,这样就避免了重新渲染。`React.memo()` 只有在 props 改变时才会起作用。如果一个函数组件被 React.memo 包裹,并且又使用了 useState、 useReducer 或者 useContext,它将会在 state 或者 context 改变时重新渲染。 ```tsx import { memo } from 'react'; @@ -551,11 +547,11 @@ const MemoComponent = memo(MemoComponent = (props) => { }); ``` -[Learn more](https://react.dev/reference/react/memo) +[了解更多](https://react.dev/reference/react/memo) -### 30. What is React Fragment? +### 30. 什么是 React Fragment? -Returning multiple elements from a component is a common practice in React. Fragments allow you to form a list of child elements without creating unnecessary nodes in the DOM. +在 React 的一个组件中返回多个元素是很常见的。Fragments 允许你创建一个子元素列表,而无需在 DOM 中创建不必要的节点。 ```tsx <> @@ -569,20 +565,20 @@ Returning multiple elements from a component is a common practice in React. Frag ``` -[Learn more](https://react.dev/reference/react/Fragment) +[了解更多](https://react.dev/reference/react/Fragment) -### 31. What is React Reconciliation? +### 31. 什么是 React Reconciliation? -Reconciliation is a React algorithm used to distinguish one tree of elements from another to determine the parts that will need to be replaced. -Reconciliation is the algorithm behind what we used to call Virtual DOM. The definition sounds something like this: when you render a React application, the element tree that describes the application is generated in reserved memory. This tree is then included in the rendering environment - for example, a browser application, it is translated into a set of DOM operations. When the application state is updated, a new tree is generated. The new tree is compared with the previous one in order to calculate and enable exactly the operations that are needed to redraw the updated application. +Reconciliation 是 React 中的一个算法,用来从组件树中筛选出需要被替换的部分。 +Reconciliation 是 以前我们所谓的虚拟 DOM 背后的算法。它的定义类似于这样: 当你渲染一个 React 程序, 描述应用程序的元素树是在内存中生成并保留的。这棵树被囊括在渲染环境中,例如在一个浏览器应用程序,这棵树被转化为一系列的 DOM 操作。 +当应用程序的状态更新时,一棵新的树就会生成。然后将新旧树进行对比,准确地计算出下一次渲染更新需要做那些操作。 -[Learn more](https://react.dev/learn/preserving-and-resetting-state) -### 32. Why do we need keys in lists when using map()? +[了解更多](https://react.dev/learn/preserving-and-resetting-state) -The keys help React determine which elements have been changed, -added, or removed. They must be specified so that React can match -array elements over time. The best way to choose a key is to use a string that will clearly distinguish the list item from its neighbors. Most often, you will use the IDs from your data as keys. +### 32. 在列表中使用 map() 为什么需要 key? + +key 帮助 React 确定哪些元素被改变了,新增了那些元素,删除了哪些元素。这些元素必须被准确地标记出来,这样 React 才能够匹配不断更新的数组元素。选择 key 最好的方式是用一个能区别其他所有元素的字符串。通常,你会使用数据中的 ID 作为 key。 ```tsx const languages = [ @@ -604,7 +600,7 @@ const App = () => { return (
@@ -612,11 +608,11 @@ const App = () => { } ``` -[Learn more](https://react.dev/learn/rendering-lists#keeping-list-items-in-order-with-key) +[了解更多](https://react.dev/learn/rendering-lists#keeping-list-items-in-order-with-key) -### 33. How to handle asynchronous actions in Redux Thunk? +### 33. 在 Redux Thunk 中怎么处理异步 actions? -To use Redux Thunk, you need to import it as middleware. Action creators should return not just an object but a function that takes dispatch as a parameter. +要使用 Redux Thunk, 你需要把它作为一个中间件导入进来。 Action creators 不应该仅仅返回一个对象而是一个接收 dispatch 参数的函数。 ```ts export const addUser = ({ firstName, lastName }) => { @@ -638,11 +634,11 @@ export const addUser = ({ firstName, lastName }) => { } ``` -[Learn more](https://redux.js.org/usage/writing-logic-thunks) +[了解更多](https://redux.js.org/usage/writing-logic-thunks) -### 34. How to track changes in a field of an object in a functional component? +### 34. 在函数式组件中怎么追踪对象中某个字段的变化? -To do this, you need to use the `useEffect` hook and pass the field of the object as a dependency array. +要做到这一点, 你需要使用 `useEffect` 钩子并且把该字段传入依赖数组。 ```ts useEffect(() => { @@ -650,9 +646,9 @@ useEffect(() => { }, [obj.someField]) ``` -### 35. How to access a DOM element? +### 35. 怎么访问一个 DOM 节点? -Refs are created using `React.createRef()` or the `useRef()` hook and attached to React elements through the ref attribute. By accessing the created reference, we can gain access to the DOM element using `ref.current`. +Refs 可以通过 `React.createRef()` 或者 `useRef()` 钩子创建,它可以通过 ref 属性应用到 React 元素上。 通过访问创建的 ref 的引用, 我们可以使用 `ref.current` 访问 DOM 节点。 ```tsx const App = () => { @@ -673,22 +669,24 @@ const App = () => { export default App; ``` -### 36. What is a custom hook? +### 36. 什么是自定义钩子? -Custom hook is a function that allows you to reuse logic between different components. It is a way to encapsulate reusable logic so that it can be easily shared and reused across multiple components. Custom hooks are functions that typically start with the word \*_use \*_ and can call other hooks if needed. +自定义钩子是一个函数,这个函数允许你在不同组件之间复用代码逻辑。 +它是封装可复用逻辑的一种方法,这样就可以方便地跨多个组件共享和复用它。 +自定义钩子是通常以单词 * _ use * _ 开头的函数,如果需要,也可以调用其他钩子。 -[Learn more](https://react.dev/learn/reusing-logic-with-custom-hooks) +[了解更多](https://react.dev/learn/reusing-logic-with-custom-hooks) -### 37. What is Public API? +### 37. 什么是 Public API? -In the context of index files, a Public API typically refers to the interface or functions that are exposed and accessible to external modules or components. -Here's a code example of an index file representing a Public API: +在索引文件的上下文中,Public API 通常指的是外部模块或组件可以公开和访问的接口或函数。 +下面是表示 Public API 的索引文件的代码示例 ```js // index.js export function greet(name) { - return `Hello, ${name}!`; + return “Hello, ${name}!“; } export function calculateSum(a, b) { @@ -696,7 +694,7 @@ export function calculateSum(a, b) { } ``` -In this example, the index.js file acts as a Public API where the functions `greet()` and `calculateSum()` are exported and can be accessed from other modules by importing them. Other modules can import and use these functions as part of their implementation: +在这个示例中,index.js 文件充当一个公共 API,其中导出了函数`greet()`和`calculateSum()`,并且可以通过导入它们从其他模块访问它们。其他模块可以导入并使用这些函数作为其实现的一部分 ```js // main.js @@ -707,44 +705,46 @@ console.log(greet('John')); // Hello, John! console.log(calculateSum(5, 3)); // 8 ``` -By exporting specific functions from the index file, we are defining the Public API of the module, allowing other modules to use those functions. +通过从索引文件导出特定的函数,我们定义了模块的 Public API,允许其他模块使用这些函数。 + +### 38. 创建一个自定义 hook 有哪些规则? -### 38. What are the rules for creating a custom hook? +1. 以 use 开头来命名 hook。 +2. 如果需要的话使用已有的 hook。 +3. 不要在条件语句中调用 hook。 +4. 把可复用的逻辑抽离到自定义 hook 中。 +5. 自定义 hook 必须是纯函数。 +6. 自定义 hook 可以返回值或者其他 hook。 +7. 描述性地命名自定义hook。 -1. Start the hook name with "use". -2. Use existing hooks if needed. -3. Don't call hooks conditionally. -4. Extract reusable logic into the custom hook. -5. Custom hooks must be pure functions. -6. Custom hooks can return values or other hooks. -7. Name the custom hook descriptively. [Learn more](https://react.dev/learn/reusing-logic-with-custom-hooks) +[了解更多](https://react.dev/learn/reusing-logic-with-custom-hooks) -### 39. What is SSR (Server-Side Rendering)? +### 39. 什么是 SSR(Server-Side Rendering)? -Server-Side Rendering (SSR) is a technique used to render pages on the server and send the fully rendered page to the client for display. It allows the server to generate the complete HTML markup of a web page, including its dynamic content, and send it to the client as a response to a request. +服务器端呈现(SSR)是一种用于在服务器上呈现页面并将完全呈现的页面发送到客户端以供显示的技术。它允许服务器生成网页的完整 HTML 标记,包括其动态内容,并将其作为对请求的响应发送给客户机。 -In a traditional client-side rendering approach, the client receives a minimal HTML page and then makes additional requests to the server for data and resources, which are used to render the page on the client-side. This can lead to slower initial page loading times and negatively impact search engine optimization (SEO) since search engine crawlers have difficulty indexing JavaScript-driven content. +在传统的客户端呈现方法中,客户端接收最小的 HTML 页面,然后向服务器发出额外的数据和资源请求,这些数据和资源用于在客户端呈现页面。由于搜索引擎爬虫难以索引 JavaScript 驱动的内容,这可能导致初始页面加载时间变慢,并对搜索引擎搜索引擎优化(SEO)造成负面影响。 -With SSR, the server takes care of rendering the web page by executing the necessary JavaScript code to produce the final HTML. This means that the client receives the fully rendered page from the server, reducing the need for additional resource requests. SSR improves initial page load times and allows search engines to easily index the content, resulting in better SEO. +使用 SSR,服务器通过执行必要的 JavaScript 代码来生成最终的 HTML,从而负责呈现网页。这意味着客户端从服务器接收完全呈现的页面,从而减少对额外资源请求的需求。SSR 提高了初始页面加载时间,并允许搜索引擎轻松索引内容,从而实现更好的 SEO。 -SSR is commonly used in frameworks and libraries like Next.js for React and Nuxt.js for Vue.js to enable server-side rendering capabilities. These frameworks handle the server-side rendering logic for you, making it easier to implement SSR. +SSR 通常用于框架和库中,比如用于 React 的 Next.js 和用于 Vue.js 的 Nuxt.js,以支持服务器端呈现功能。这些框架为你处理服务器端呈现逻辑,使得实现 SSR 更加容易。 -### 40. What are the benefits of using SSR? +### 40. 使用 SSR 的好处是什么? -1. **Improved initial loading times**: SSR allows the server to send a fully rendered HTML page to the client, reducing the amount of processing required on the client-side. This improves the initial loading times, as the user sees a complete page more quickly. +1. **优化初始加载时间**: SSR 允许服务器向客户端发送完整的 HTML 页面,从而减少客户端所需的处理量。这优化了初始加载时间,因为用户可以更快地看到完整的页面。 -2. **SEO-friendly**: Search engines can efficiently crawl and index the content of SSR pages because the fully rendered HTML is available in the initial response. This improves search engine visibility and helps with better search rankings. +2. **对SEO友好**: 搜索引擎可以有效地抓取和索引 SSR 页面的内容,因为完整的 HTML 在初始响应中是可用的。这提高了搜索引擎的可见性,并有助于更好的搜索排名。 -3. **Accessibility**: SSR ensures that the content is accessible to users who have JavaScript disabled or use assistive technologies. By generating HTML on the server, SSR provides a reliable and accessible user experience for all users. +3. **可访问性**: SSR 确保禁用 JavaScript 或使用辅助技术的用户可以访问内容。通过在服务器上生成 HTML,SSR 为所有用户提供了可靠和可访问的用户体验。 -4. **Performance in low-bandwidth environments**: SSR reduces the amount of data needed to be downloaded by the client, making it beneficial for users in low-bandwidth or high-latency environments. This is particularly important for mobile users or users with slower internet connections. +4. **低带宽环境下的性能**: SSR 可以减少客户端需要下载的数据量,从而有利于低带宽或高延迟环境中的用户。这对于移动用户或互联网连接较慢的用户尤其重要。 -While SSR offers these benefits, it's important to note that it may introduce more server load and maintenance complexity compared to client-side rendering methods. Careful consideration should be given to factors such as caching, scalability, and server-side rendering performance optimizations. +虽然 SSR 提供了这些好处,但是需要注意的是,与客户端渲染方法相比,它可能会引入更多的服务器负载和维护复杂性。应该仔细考虑缓存、可伸缩性和服务器端渲染性能优化等因素。 -### 41. What are the main functions of Next.js that you know? +### 41. 你所知道的 Next.js 的主要功能是什么? -1. `getStaticProps`: This method is used to fetch data at build time and pre-render a page as static HTML. It ensures that the data is available at build time and does not change on subsequent requests. +1. `getStaticProps`: 此方法用于在生成时获取数据并预先将页面呈现为静态 HTML。它确保数据在构建时可用,并且不会在后续请求中更改。 ```tsx export async function getStaticProps() { @@ -759,7 +759,7 @@ export async function getStaticProps() { } ``` -1. `getServerSideProps`: This method is used to fetch data on each request and pre-render the page on the server. It can be used when you need to fetch data that might change frequently or is user-specific. +1. `getServerSideProps`: 此方法用于获取每个请求的数据并在服务器上预渲染页面。当你需要获取可能经常更改或特定于用户的数据时,可以使用它。 ```ts export async function getServerSideProps() { @@ -774,7 +774,7 @@ export async function getServerSideProps() { } ``` -1. `getStaticPaths`: This method is used in dynamic routes to specify a list of paths that should be pre-rendered at build time. It is commonly used to fetch data for dynamic routes with parameters. +1. `getStaticPaths`: 此方法在动态路由中用于指定应在生成时预渲染的路径列表。它通常用于带参数的动态路由获取数据。 ```ts export async function getStaticPaths() { @@ -792,67 +792,67 @@ export async function getStaticPaths() { } ``` -[Learn more](https://nextjs.org/docs/app/building-your-application/data-fetching/fetching-caching-and-revalidating) +[了解更多](https://nextjs.org/docs/app/building-your-application/data-fetching/fetching-caching-and-revalidating) -### 42. What are linters? +### 42. 什么是 linters? -Linters are tools used to check source code for potential errors, bugs, stylistic inconsistencies, and maintainability issues. They help enforce coding standards and ensure code quality and consistency across a codebase. +Linters 是用来检查源代码是否存在潜在错误、 bug、风格不一致和可维护性问题的工具。它们有助于强制执行编码标准,并确保代码质量和跨代码库的一致性。 -Linters work by scanning the source code and comparing it against a set of predefined rules or guidelines. These rules can include syntax and formatting conventions, best practices, potential bugs, and code smells. When a linter identifies a violation of a rule, it generates a warning or an error, highlighting the specific line or lines of code that need attention. +Linters 通过扫描源代码并将其与一组预定义的规则或指南进行比较来工作。这些规则包含语法和格式约定、最佳实践、潜在的 bug 和代码异味。当一个 linter 辨别出不符合规则的代码,它会生成一个警告或错误,高亮展示需要注意的特定行或代码行。 -Using a linter can provide several benefits: +使用 Linter 可以带来几个好处: -1. **Code Quality**: Linters help identify and prevent potential bugs, code smells, and anti-patterns, leading to better code quality. +1. **代码质量**: Linters 有助于识别和防止潜在的 bug、代码味道和反模式,从而提高代码质量。 -2. **Consistency**: Linters enforce coding conventions and style guidelines, ensuring consistent formatting and code structure across the codebase, even when multiple developers are working on the same project. +2. **一致性**: Linters 强制执行编码约定和样式指南,确保跨代码库的一致格式和代码结构,即使当多个开发人员在同一个项目中工作时也是如此。 -3. **Maintainability**: By catching issues early and promoting good coding practices, linters contribute to code maintainability, making it easier to understand, modify, and extend the codebase. +3. **可维护性**: 通过及早发现问题和促进良好的编码实践,linter 有助于代码的可维护性,使代码库更容易理解、修改和扩展。 -4. **Efficiency**: Linters can save developers time by automating code review processes and catching common mistakes before they can cause issues during development or in production. +4. **高效性**: 通过自动化代码审查过程和在常见错误导致开发过程或生产过程中出现问题之前捕捉常见错误,Linters 可以节省开发人员的时间。 -Some popular linters are ESLint for JavaScript and Stylelint for CSS and Sass. +一些流行的 linters 有用于 JavaScript 的 ESLint 和用于 CSS 和 Sass 的 Stylelint。 -[Learn more](https://eslint.org/docs/latest/use/getting-started) +[了解更多](https://eslint.org/docs/latest/use/getting-started) -### 43. What architectural solutions for React do you know? +### 43. 你知道 React 的什么架构解决方案吗? -There are several architectural solutions and patterns for building React projects. Some popular ones include: +有几种架构解决方案和模式可以用来构建 React 项目,其中一些比较流行的方案包括: -1. **MVC (Model-View-Controller)**: MVC is a traditional architectural pattern that separates an application into three main components - Model, View, and Controller. React can be used in the View layer to render the UI, while other libraries or frameworks can be used for the Model and Controller layers. +1. **MVC (Model-View-Controller)**: MVC 是一种传统的体系结构模式,它将应用程序分为三个主要组件——模型、视图和控制器。React 可用于视图层呈现 UI,而其他库或框架可用于模型和控制器层。 -2. **Flux**: Flux is an application architecture introduced by Facebook specifically for React applications. It follows a unidirectional data flow, where data flows in a single direction, making it easier to understand and debug the application's state changes. +2. **Flux**: Flux 是 Facebook 专门为 React 应用程序引入的应用程序架构。它遵循单向数据流,其中数据沿单个方向流动,从而更容易理解和调试应用程序的状态更改。 -3. **Atomic Design**: Atomic Design is not specific to React but is a design methodology that divides the UI into smaller, reusable components. It encourages building components that are small, self-contained, and can be composed to create more complex UIs. +3. **原子设计**: 原子设计并不是 React 特有的,而是一种将 UI 划分为更小的可重用组件的设计方法。它鼓励构建小型的、自包含的、可以组合以创建更复杂的 UI 的组件。 -4. **Container and Component Pattern**: This pattern separates the presentation (Component) from the logic and state management (Container). Components are responsible for rendering the UI, while Containers handle the business logic and state management. +4. **容器与组件模式**: 此模式将表现(组件)与逻辑和状态管理(容器)分离。组件负责呈现 UI,而容器负责处理业务逻辑和状态管理。 -5. **Feature-Sliced Design**: It is a modern architectural approach used to organize and structure React applications. It aims to address the challenges of scalability, maintainability, and reusability by dividing the application codebase based on features or modules. +5. **特性切片设计**: 它是一种用于组织和构建 React 应用程序的现代体系结构方法。它旨在通过基于特性或模块划分应用程序代码库来解决可伸缩性、可维护性和可重用性方面的挑战。 -### 44. What is Feature-Sliced Design? +### 44. 什么是特性切片设计? -It is a modern architectural approach used to organize and structure React applications. It aims to address the challenges of scalability, maintainability, and reusability by dividing the application codebase based on features or modules. +它是一种用于组织和构建 React 应用程序的现代体系结构方法。它旨在通过基于特性或模块划分应用程序代码库来解决可伸缩性、可维护性和可重用性方面的挑战。 -In Feature-Sliced Design, each feature or module of the application is organized into a separate directory, containing all the necessary components, actions, reducers, and other related files. This helps in keeping the codebase modular and isolated, making it easier to develop, test, and maintain. +在功能切片设计中,应用程序的每个功能或模块被组织到一个单独的目录中,包含所有必要的组件、操作、减少器和其他相关文件。这有助于保持代码库的模块化和隔离性,使其更容易开发、测试和维护。 -Feature-Sliced Design promotes a clear separation of concerns and encapsulates the functionality within individual features. This allows different teams or developers to work on different features independently, without worrying about conflicts or dependencies. +功能切片设计促进了一个清晰的关注点分离,并将功能封装在个别功能中。这允许不同的团队或开发人员独立处理不同的特性,而不必担心冲突或依赖性。 [![Feature-Sliced Design](https://res.cloudinary.com/practicaldev/image/fetch/s--Cuy79Z1p--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_800/https://dev-to-uploads.s3.amazonaws.com/uploads/articles/amysbtftfjkuss87yu8v.png)](https://res.cloudinary.com/practicaldev/image/fetch/s--Cuy79Z1p--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_800/https://dev-to-uploads.s3.amazonaws.com/uploads/articles/amysbtftfjkuss87yu8v.png) -**I highy recommend to click on the Learn more button to learn about Feature-Sliced Design** +**我强烈建议你点击“了解更多”按钮来学习“特性切片设计”** -[Learn more](https://dev.to/m_midas/feature-sliced-design-the-best-frontend-architecture-4noj) +[了解更多](https://dev.to/m_midas/feature-sliced-design-the-best-frontend-architecture-4noj) -## Learn more +## 了解更多 -I strongly recommend reading the rest of my articles on frontend interview questions, if you haven't already. +如果你还没有读过我关于前端面试问题的其他文章,我强烈建议你读一读。 -## Conclusion +## 结语 -In conclusion, interviewing for a React Frontend Developer position requires a solid understanding of the framework's core concepts, principles, and related technologies. By preparing for the questions discussed in this article, you can showcase your React knowledge and demonstrate your ability to create efficient and maintainable user interfaces. Remember to not only focus on memorizing answers but also understanding the underlying concepts and being able to explain them clearly. -Additionally, keep in mind that interviews are not just about the technical aspects but also about showcasing your problem-solving skills, communication abilities, and how well you can work in a team. By combining technical expertise with a strong overall skill set, you'll be well-equipped to excel in React frontend developer interviews and land your dream job in this exciting and rapidly evolving field. -Good luck! +总之,应聘 React Fronend Developer 职位需要对框架的核心概念、原则和相关技术有扎实的理解。通过准备本文讨论的问题,你可以展示你的 React 知识,并展示你创建高效和可维护的用户界面的能力。记住,不仅要专注于记忆答案,还要理解基本概念,并能够清楚地解释它们。 +此外,请记住,面试不仅仅是技术方面的问题,也是展示你解决问题的技巧、沟通能力以及如何在团队中工作的问题。通过结合技术专业知识和强大的整体技能集,你将有充分的准备,在前端开发面试中有出色的表现,并且能够在这个令人兴奋的和迅速发展的领域找到你的理想工作。 +祝你好运! ---