callback

简明释义

英[ˈkɔːlbæk]美[ˈkɔːlbæk]

n. 回收；回叫信号

英英释义

单词用法

同义词

反义词

例句

1.All you add is a callback function.

您仅需要添加一个回调函数。

2.The callback is called the event handler.

回调被称为事件处理器。

3.I've also attached a callback function.

同时我也附加了一个回调函数。

4.Within the callback function, the returned data can be processed.

在该回调函数内，可能处理返回的数据。

5.It also implements a callback scheme for responses.

它还为响应实现回调模式。

6.Pass session information to the async callback handler.

将会话信息传递到异步回调处理程序。

7.The following code sample shows the use of the callback handler.

下面的代码展示了回调处理程序的使用方法。

8.The customer service representative promised a callback 回电 within 24 hours.

客服代表承诺在24小时内进行一次回电。

9.If you miss the call, please request a callback 回电 from the operator.

如果你错过了电话，请向接线员请求一次回电。

10.The software uses a callback 回调 function to execute code after an event.

该软件使用回调函数在事件发生后执行代码。

11.I left a message for a callback 回电 regarding my account issue.

我留下了一条信息，要求关于我的账户问题的回电。

12.In programming, a callback 回调 is often used to handle asynchronous operations.

在编程中，回调通常用于处理异步操作。

作文

In the world of technology and programming, the term callback refers to a function that is passed as an argument to another function. This concept is crucial in asynchronous programming, where operations do not block the execution of code. For instance, when you make a request to a server to fetch data, instead of waiting for the response, the program can continue executing other code. Once the server responds, the callback function is executed with the response data. This allows for a more efficient use of resources and improves the overall performance of applications. To illustrate this, consider a simple example in JavaScript. When you want to load user information from a database, you might write a function called `fetchUserData`. Instead of making the application wait for the data to load, you can pass a callback function that will process the data once it is available. This approach not only keeps the application responsive but also makes your code cleaner and easier to manage. Moreover, callbacks are not limited to just asynchronous operations. They can also be used in synchronous programming to handle events or actions that need to occur after a certain function has completed. For example, when a user clicks a button on a webpage, you can attach a callback function to that event. This function will execute immediately after the button click, allowing you to perform any necessary actions, such as updating the user interface or sending data to a server. However, while callbacks are powerful, they can also lead to complex code structures, especially when multiple callbacks are nested within one another. This phenomenon is often referred to as 'callback hell,' where the code becomes difficult to read and maintain. To combat this issue, modern programming languages have introduced features like Promises and async/await syntax, which help to flatten the structure of asynchronous code and avoid deep nesting of callbacks. In addition to programming, the concept of callback is also prevalent in various fields such as customer service and job recruitment. In customer service, a callback refers to a situation where a representative promises to return a call to a customer who has left a message or inquiry. This ensures that the customer's needs are addressed promptly without making them wait on hold. In the context of job recruitment, a callback is an invitation for a candidate to return for a second interview after their initial meeting. It signifies that the candidate has made a positive impression and is being considered further for the position. Receiving a callback in this context is often seen as a good sign and can motivate candidates to prepare even more thoroughly for the next stage of the hiring process. In conclusion, the term callback encompasses a variety of meanings across different domains, but its core idea revolves around the notion of responding to an action or event. Whether in programming, customer service, or recruitment, understanding the role of callbacks can enhance efficiency and effectiveness. As technology continues to evolve, the importance of mastering callback mechanisms and their applications will remain a valuable skill for professionals in many fields.

在技术和编程的世界中，术语callback指的是作为参数传递给另一个函数的函数。这个概念在异步编程中至关重要，因为在异步编程中，操作不会阻塞代码的执行。例如，当您向服务器请求以获取数据时，程序可以继续执行其他代码，而不是等待响应。一旦服务器响应，将执行callback函数，并传入响应数据。这允许更有效地利用资源，并改善应用程序的整体性能。 为了说明这一点，考虑一个简单的JavaScript示例。当您想从数据库加载用户信息时，您可能会编写一个名为`fetchUserData`的函数。您可以传递一个callback函数来处理数据，而不是让应用程序等待数据加载。这种方法不仅保持了应用程序的响应能力，还使您的代码更简洁、更易于管理。 此外，callbacks不仅限于异步操作。它们也可以用于同步编程，以处理某些函数完成后需要发生的事件或动作。例如，当用户单击网页上的按钮时，您可以将一个callback函数附加到该事件上。该函数将在按钮单击后立即执行，允许您执行任何必要的操作，例如更新用户界面或将数据发送到服务器。 然而，虽然callbacks非常强大，但它们也可能导致复杂的代码结构，尤其是当多个callbacks嵌套在一起时。这种现象通常被称为“回调地狱”，其中代码变得难以阅读和维护。为了应对这个问题，现代编程语言引入了Promise和async/await语法等功能，这有助于扁平化异步代码的结构，避免深度嵌套的callbacks。 除了编程之外，callback的概念在客户服务和招聘等各个领域也很普遍。在客户服务中，callback指的是代表承诺在客户留下留言或询问后回电的情况。这确保了客户的需求得到及时解决，而无需让他们等待。 在招聘的背景下，callback是对候选人的邀请，要求他们在初次面试后返回进行第二次面试。这表明候选人给人留下了积极的印象，并正在进一步考虑该职位。在这种情况下收到callback通常被视为一个好兆头，可以激励候选人更加充分地准备下一阶段的招聘过程。 总之，术语callback在不同领域包含多种含义，但其核心思想围绕响应某个动作或事件的概念。无论是在编程、客户服务还是招聘中，理解callbacks的作用可以提高效率和效果。随着技术的不断发展，掌握callback机制及其应用的重要性将继续成为许多领域专业人士的一项宝贵技能。