How to call css in html
HTML (HyperText Markup Language) is the markup language of web pages, while CSS (Cascading Style Sheets) is the language used to define the style and layout of web pages. In web development, both HTML and CSS play important roles. HTML is responsible for the definition of web page structure and elements, while CSS is used to control the style of elements. This article will introduce how HTML calls CSS styles.
1. Internal Style
In HTML, CSS can be defined by using the <style>
tag in the <head>
tag style, this is called "internal style". The specific steps are as follows:
- Add the
<style>
tag in the<head>
tag. - Define CSS styles in
<style>
tags. - Use the
style
attribute in HTML elements to call CSS styles.
For example, the following code defines a red title and applies it to the <h1>
tag:
<!DOCTYPE html> <html> <head> <style> h1 { color: red; } </style> </head> <body> <h1 style="color: red;">Hello, World!</h1> </body> </html>
- External style
In addition to internal styles, CSS files can also be used externally. External styles place all CSS style definitions in a separate file and then reference that file using links in the HTML. The specific steps are as follows:
- Create a CSS file and define the style.
- Use the
<link>
tag in HTML to link CSS files.
For example, we can save the CSS style in the above example in a file named style.css
, and then use <link> in the HTML file The ;
tag links them as follows:
index.html File:
<!DOCTYPE html> <html> <head> <link rel="stylesheet" type="text/css" href="style.css"> </head> <body> <h1>Hello, World!</h1> </body> </html>
style.css File:
h1 { color: red; }
- Inline Style
Inline styles are also a way to call CSS styles, but unlike internal styles, inline styles are CSS styles that are applied directly to the style
attribute of the HTML element. This means that individual styles can be defined in HTML tags without the need to define styles in the <head>
tag or use an external CSS file. However, inline styles are not recommended because they increase the size of the HTML file and reduce readability, and are difficult to maintain.
For example, the following code defines a red title and applies it to the <h1>
tag:
<!DOCTYPE html> <html> <head> </head> <body> <h1 style="color: red;">Hello, World!</h1> </body> </html>
Summary
In In HTML, CSS styles can be called in three ways: internal styles, external styles, and inline styles. Among them, internal styles apply to a single page or application, external styles can be used by multiple pages or applications, and inline styles apply to specific styles on a single element. In actual applications, the appropriate way to call CSS styles should be selected according to needs and situations to optimize performance and improve development efficiency.
The above is the detailed content of How to call css in html. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











The advantages of React are its flexibility and efficiency, which are reflected in: 1) Component-based design improves code reusability; 2) Virtual DOM technology optimizes performance, especially when handling large amounts of data updates; 3) The rich ecosystem provides a large number of third-party libraries and tools. By understanding how React works and uses examples, you can master its core concepts and best practices to build an efficient, maintainable user interface.

The React ecosystem includes state management libraries (such as Redux), routing libraries (such as ReactRouter), UI component libraries (such as Material-UI), testing tools (such as Jest), and building tools (such as Webpack). These tools work together to help developers develop and maintain applications efficiently, improve code quality and development efficiency.

React's future will focus on the ultimate in component development, performance optimization and deep integration with other technology stacks. 1) React will further simplify the creation and management of components and promote the ultimate in component development. 2) Performance optimization will become the focus, especially in large applications. 3) React will be deeply integrated with technologies such as GraphQL and TypeScript to improve the development experience.

React is a JavaScript library developed by Meta for building user interfaces, with its core being component development and virtual DOM technology. 1. Component and state management: React manages state through components (functions or classes) and Hooks (such as useState), improving code reusability and maintenance. 2. Virtual DOM and performance optimization: Through virtual DOM, React efficiently updates the real DOM to improve performance. 3. Life cycle and Hooks: Hooks (such as useEffect) allow function components to manage life cycles and perform side-effect operations. 4. Usage example: From basic HelloWorld components to advanced global state management (useContext and

React is a front-end framework for building user interfaces; a back-end framework is used to build server-side applications. React provides componentized and efficient UI updates, and the backend framework provides a complete backend service solution. When choosing a technology stack, project requirements, team skills, and scalability should be considered.

React's main functions include componentized thinking, state management and virtual DOM. 1) The idea of componentization allows splitting the UI into reusable parts to improve code readability and maintainability. 2) State management manages dynamic data through state and props, and changes trigger UI updates. 3) Virtual DOM optimization performance, update the UI through the calculation of the minimum operation of DOM replica in memory.

The application of React in HTML improves the efficiency and flexibility of web development through componentization and virtual DOM. 1) React componentization idea breaks down the UI into reusable units to simplify management. 2) Virtual DOM optimization performance, minimize DOM operations through diffing algorithm. 3) JSX syntax allows writing HTML in JavaScript to improve development efficiency. 4) Use the useState hook to manage state and realize dynamic content updates. 5) Optimization strategies include using React.memo and useCallback to reduce unnecessary rendering.

React is a JavaScript library developed by Facebook for building user interfaces. 1. It adopts componentized and virtual DOM technology to improve the efficiency and performance of UI development. 2. The core concepts of React include componentization, state management (such as useState and useEffect) and the working principle of virtual DOM. 3. In practical applications, React supports from basic component rendering to advanced asynchronous data processing. 4. Common errors such as forgetting to add key attributes or incorrect status updates can be debugged through ReactDevTools and logs. 5. Performance optimization and best practices include using React.memo, code segmentation and keeping code readable and maintaining dependability
