Home Web Front-end Front-end Q&A How to use external javascript files

How to use external javascript files

May 20, 2023 pm 08:29 PM

In modern web development, JavaScript (JS for short) has become an indispensable part. JS can not only achieve dynamic effects on web pages, but also facilitate code modularization and reuse through external JavaScript files. This article explains how to use external JavaScript files and the benefits of using external JavaScript files.

First, we need to understand what an external JavaScript file is. External JavaScript files refer to saving JS code in a separate JavaScript file and introducing it in HTML through the <script> tag. External JS files have separate file paths and file names, and references can be shared across multiple HTML pages.

Next, let’s take a look at how to use external JavaScript files.

Step 1: Create an external JavaScript file
To use an external JavaScript file, you need to create an independent .js file first. You can create files through any editor, such as Notepad or Sublime Text. Write your JS code in a file and save the file as a standalone JS file, such as myscript.js.

Step 2: Introduce external JavaScript files into HTML
To introduce external JavaScript files into HTML files, you need to use the <script> tag. There are two attributes in the tag: src and type. The src attribute is used to specify the path of the JS file, and the type attribute is used to specify the type of the JS file, usually set to text/javascript. The following is a code example that introduces an external JavaScript file:

<!DOCTYPE html>
<html>
<head>
  <script src="myscript.js" type="text/javascript"></script>
</head>
<body>

</body>
</html>
Copy after login

The above code will introduce an external file named myscript.js in the <head> tag of HTML JavaScript files. In this way, when the HTML is loaded, the JS file will also be loaded and the code in it will be executed.

Benefit Analysis: Benefits of Using External JavaScript Files
Now, let’s take a look at the benefits of using external JavaScript files.

  1. Improve code maintainability
    Separating JS code into independent files can make the code more structured and easier to maintain. If you want to modify the code, you only need to modify a separate file instead of modifying the code in each HTML file.
  2. Facilitates code reuse
    If you have multiple HTML files that need to use the same JS code, then using external JavaScript files can easily achieve code reuse. Just introduce the same JS file in different HTML files.
  3. Reduce the loading time of the code
    Using external JS files can reduce the size of the HTML file, thereby reducing the loading time of the page. Because JS files can be cached, if multiple HTML pages reference the same JS file, then when the first page loads the JS file, it will already be cached, so that the file will not be downloaded again on subsequent page loads.

Summary
In this article, we learned how to use external JavaScript files and the benefits of using external JavaScript files. For larger projects, using external JavaScript files can make the code more structured, easier to maintain and reuse, and can also help reduce page load times. Therefore, it is necessary to use external JavaScript files in the project. It is recommended that you modularize the JavaScript code as much as possible to better manage and maintain the code.

The above is the detailed content of How to use external javascript files. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

What is useEffect? How do you use it to perform side effects? What is useEffect? How do you use it to perform side effects? Mar 19, 2025 pm 03:58 PM

The 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. Explain the concept of lazy loading. Mar 13, 2025 pm 07:47 PM

Lazy 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? 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 PM

Higher-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? How does currying work in JavaScript, and what are its benefits? Mar 18, 2025 pm 01:45 PM

The 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? How does the React reconciliation algorithm work? Mar 18, 2025 pm 01:58 PM

The 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

What is useContext? How do you use it to share state between components? What is useContext? How do you use it to share state between components? Mar 19, 2025 pm 03:59 PM

The 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.

How do you prevent default behavior in event handlers? How do you prevent default behavior in event handlers? Mar 19, 2025 pm 04:10 PM

Article discusses preventing default behavior in event handlers using preventDefault() method, its benefits like enhanced user experience, and potential issues like accessibility concerns.

What are the advantages and disadvantages of controlled and uncontrolled components? What are the advantages and disadvantages of controlled and uncontrolled components? Mar 19, 2025 pm 04:16 PM

The 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.

See all articles