In the field of front-end development, interviews are an important part of assessing a candidate's skills and knowledge level. The interview questions cover all aspects of front-end knowledge and are designed to examine candidates' ability to understand and solve problems. This article will introduce some common front-end interview questions, combined with specific examples to help readers better understand and prepare for front-end interviews.
1. Please explain what is the CSS box model, and explain the various parts of the box model.
The CSS box model refers to the model used to describe the layout and rendering of HTML elements. It consists of four parts: content (content), padding (padding), border (border) and margin (margin).
Concrete example:
div {
width: 200px; height: 100px; padding: 10px; border: 1px solid black; margin: 20px; }
In the above example, the div element has a width of 200px and a height of 100px. The padding is 10px, the border is 1px solid black, and the margin is 20px. Together, these parts form a rectangular box that defines the size and position of the element.
2. Please explain what responsive design is and describe how to implement a responsive layout.
Responsive design is a design philosophy that aims to make web pages look their best on different devices and screen sizes. Common ways to implement responsive layouts include using media queries and flexbox.
Concrete example:
@media screen and (max-width: 600px) {
.container { flex-direction: column; } }
In the above example, media queries are used to apply different CSS rules for screens smaller than 600px wide. When the screen width is less than 600px, the flex-direction property of the container will be set to column (column) to achieve vertical layout.
3. Please explain what is a cross-origin request and how to solve cross-origin issues.
A cross-domain request refers to a request initiated by JavaScript in a browser, and its target server is different from the domain name of the current page. For security reasons, browsers restrict cross-origin requests. In order to solve cross-domain problems, methods such as CORS (Cross-Origin Resource Sharing), JSONP (JSON with Padding) or proxy servers can be used.
Concrete example:
// Use CORS to solve cross-domain problems
// 前端代码 fetch('https://api.example.com/data', { method: 'GET', mode: 'cors' }) .then(response => response.json()) .then(data => console.log(data)) .catch(error => console.log(error));
In the above example, by setting the mode parameter of the fetch function to cors, data can be requested from servers in different domains to achieve cross-domain communication.
4. Please explain what is a single page application (SPA), and the advantages and disadvantages of SPA.
A Single Page Application is an application that dynamically loads content and navigates within the same page. It usually uses a JavaScript framework such as Vue.js, React or Angular to achieve dynamic rendering and routing.
Concrete example: A concrete SPA example is the application of the Vue.js framework, where page content is organized and managed through Vue components. Page switching and navigation are handled through routing (such as Vue Router) instead of traditional page refreshes.
Advantages :
- Faster page loads because only the initial page and subsequent data requests need to be loaded.
- A smoother user experience, since the entire page does not need to be reloaded when switching pages.
- Better interactivity, dynamic update and real-time data display can be realized.
Disadvantages :
- A challenge for search engine optimization (SEO), since page content is often loaded dynamically via JavaScript.
- Larger initial load time, as front-end frameworks and components need to be loaded.
in conclusion
Front-end interview questions cover multiple aspects of knowledge and skills, including HTML, CSS, JavaScript, responsive design, cross-domain issues, single-page applications, etc. When preparing for the front-end interview, candidates need to have a deep understanding of these knowledge and be able to answer with specific examples. Not only that, but it is also necessary to maintain continuous learning of the development of front-end technology to keep up with the ever-changing front-end industry.