Should the referenced javascript file be included in the script tag?
Referenced javascript files should be included in the script tag. Use the src attribute of the script tag to specify the path to the external JavaScript file, with the syntax "".
The operating environment of this tutorial: Windows 10 system, JavaScript version 1.8.5, Dell G3 computer.
Whether or not to include script tags when quoting javascript files
Quoting JavaScript files
Like CSS files, JavaScript code can be stored in a separate file. To enhance the reproducible invocation of JavaScript scripts. A JavaScript file is a text file that can be opened and edited in any text editor. The extension of a JavaScript file is js.
<script> tag is used to define client-side scripts, such as JavaScript. The </script>
<script> element can either contain script statements or point to an external script file through the "src" attribute. </script>
When introducing a JavaScript file, you can use the <script> tag. Just specify the URL (Uniform Resource Locator) of the JavaScript file through the src attribute of the tag. </script>
Example:
Create a new text file, save it as test.js, and write a public function in the file to return the length of the string
//公共函数:计算字符串的实际长度 function strlen(str){ var len;//声明临时变量,存储字符串的实际长度 var i;//声明循环变量 len = 0;//初始化临时变量len为0 for(i = 0; i < str.length; i++){//循环检测字符串中每个字符 if(str.charCodeAt(i) > 255)//如果当前字符为双字节字符,+2 len += 2; else //如果当前字符为单字节字符,+1 len++; } return len;//返回实际长度值 }
Create a new html document and introduce test.js.
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <!-- 引入外部JavaScript文件 --> <script type="text/javascript" src="test.js" ></script> </head> <script> var str = "JavaScript编程语言"; document.write("<h2 id="nbsp-nbsp-str-nbsp-nbsp">" + str + "</h2>");//输出变量的值 document.write("<p>实际长度=" + strlen(str) + "字节</p>");//调用函数 </script> <body> </body> </html>
Using external JavaScript files can enhance JavaScript modular development programs and improve code reuse. In web development, users should develop a good habit of code reuse. When writing JavaScript code, use more external JavaScript files, which can improve the speed and efficiency of project development.
Related recommendations: javascript learning tutorial
The above is the detailed content of Should the referenced javascript file be included in the script tag?. For more information, please follow other related articles on the PHP Chinese website!

C and JavaScript achieve interoperability through WebAssembly. 1) C code is compiled into WebAssembly module and introduced into JavaScript environment to enhance computing power. 2) In game development, C handles physics engines and graphics rendering, and JavaScript is responsible for game logic and user interface.

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.


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

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

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

Atom editor mac version download
The most popular open source editor

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.