In web design and development, JavaScript and CSS are used together to achieve a variety of stunning visual effects and interactive features. How JavaScript calls CSS is a common question, which will be described in detail below.
1. Inline style
Inline style can be directly applied to the style attribute of the HTML tag, as shown below:
<p style="color: red; font-size: 16px;">这是一个红色的段落</p>
In JavaScript, you can change the element by style attribute to modify the inline style. For example:
let p = document.querySelector("p");
p.style.color = "blue";
p.style.fontSize = "20px";This will turn the red paragraph above into a blue paragraph with a font size of 20px.
2. External style sheets
An external style sheet is a method of placing a collection of CSS rules in a separate file. By associating the file with an HTML document, the same one can be reused Style rules. In JavaScript, a style sheet can be modified by changing the href attribute of the element in the document that is linked to the style sheet. For example:
<link rel="stylesheet" href="styles.css">
let link = document.querySelector("link");
link.href = "new-styles.css";This changes the stylesheet in the document that is linked to styles.css to a stylesheet that is linked to new-styles.css.
3. Internal style sheet
The internal style sheet is a method of placing a collection of CSS rules between the head or body tags of an HTML document. In JavaScript, internal style sheets can be modified by directly modifying the document's style attribute. For example:
<head>
<style>
p {
color: red;
font-size: 16px;
}
</style>
</head>
<body>
<p>这是一个红色的段落</p>
</body>let style = document.querySelector("style");
style.innerHTML = "p { color: blue; font-size: 20px; }";This will turn the red paragraph above into a blue paragraph with a font size of 20px.
4. Class name
The class name is a name that defines the style rules of certain elements. In JavaScript, one or more classes can be added or removed by modifying the classList attribute of an element. For example:
<style>
.red {
color: red;
}
.large {
font-size: 20px;
}
</style>
<p class="red">这是一个红色的段落</p>let p = document.querySelector("p");
p.classList.add("large");
p.classList.remove("red");This will turn the red paragraph above into a paragraph with a font size of 20px.
Summary:
JavaScript can use a variety of methods to call CSS, including inline styles, external style sheets, internal style sheets, and class names. These methods can directly operate the Document Object Model (DOM) through JavaScript to achieve visual effects and interactive functions. Mastering these skills can help you better manage and control the style and behavior of Web pages.
The above is the detailed content of How javascript calls css. For more information, please follow other related articles on the PHP Chinese website!
What is useEffect? How do you use it to perform side effects?Mar 19, 2025 pm 03:58 PMThe article discusses useEffect in React, a hook for managing side effects like data fetching and DOM manipulation in functional components. It explains usage, common side effects, and cleanup to prevent issues like memory leaks.
Explain the concept of lazy loading.Mar 13, 2025 pm 07:47 PMLazy loading delays loading of content until needed, improving web performance and user experience by reducing initial load times and server load.
What are higher-order functions in JavaScript, and how can they be used to write more concise and reusable code?Mar 18, 2025 pm 01:44 PMHigher-order functions in JavaScript enhance code conciseness, reusability, modularity, and performance through abstraction, common patterns, and optimization techniques.
How does currying work in JavaScript, and what are its benefits?Mar 18, 2025 pm 01:45 PMThe article discusses currying in JavaScript, a technique transforming multi-argument functions into single-argument function sequences. It explores currying's implementation, benefits like partial application, and practical uses, enhancing code read
How does the React reconciliation algorithm work?Mar 18, 2025 pm 01:58 PMThe article explains React's reconciliation algorithm, which efficiently updates the DOM by comparing Virtual DOM trees. It discusses performance benefits, optimization techniques, and impacts on user experience.Character count: 159
How do you prevent default behavior in event handlers?Mar 19, 2025 pm 04:10 PMArticle discusses preventing default behavior in event handlers using preventDefault() method, its benefits like enhanced user experience, and potential issues like accessibility concerns.
What is useContext? How do you use it to share state between components?Mar 19, 2025 pm 03:59 PMThe article explains useContext in React, which simplifies state management by avoiding prop drilling. It discusses benefits like centralized state and performance improvements through reduced re-renders.
What are the advantages and disadvantages of controlled and uncontrolled components?Mar 19, 2025 pm 04:16 PMThe article discusses the advantages and disadvantages of controlled and uncontrolled components in React, focusing on aspects like predictability, performance, and use cases. It advises on factors to consider when choosing between them.
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
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
SublimeText3 Linux new version
SublimeText3 Linux latest version
Notepad++7.3.1
Easy-to-use and free code editor
PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
Dreamweaver CS6
Visual web development tools
