How to place JS script in HTML document
Methods to place JS scripts in HTML documents: 1. Place the JS script in the
tag; 2. Place the JS script in the tag; 3. Place the JS script in the and Place JS script in the tag; 4. Import js script externally.
The operating environment of this article: Windows 7 system, Dell G3 computer, html5&&javascript version 1.8.5.
The places where js scripts are placed are in the
tag, in the tag, in the and tags, as well as in the external introduction of js scriptsWe can place JavaScript code anywhere in the HTML document. However, the best way to place JavaScript code in an HTML file is as follows
1. In the
... head> section2.
.. . Place codein the body> section 3. Place code in the
... body> and ... head> sections4. Write a script in an external file, and then introduce it in the
... head> section These four methods will be explained in detail in the article
【Recommended course: JavaScript course】
In the ... head> section
If you want to run a script on a certain event, such as an event that is triggered when the user clicks a certain location, At this time we can put the script in the head
<head>
<meta charset="UTF-8">
<title>Document</title>
<script type = "text/javascript">
function Hello() {
alert("Hello World")
}
</script>
</head>Rendering:
##In
.. . sectionIf you need to run a script when the page loads so that the script generates content in the page, the script will go into the section of the document. In this case, no functions will be defined using JavaScript<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script type = "text/javascript">
document.write("Hello World")
</script>
<p>页面加载时脚本就会生成内容</p>
</body>
</html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<script type = "text/javascript">
function Hello() {
alert("Hello World")
}
</script>
</head>
<body>
<script type = "text/javascript">
document.write("Hello World")
</script>
##JavaScript in external file
When we need to reuse the same JavaScript code on multiple pages on the website, we can achieve this by introducing js files externally. To facilitate maintaining the same code, the script tag provides a mechanism that allows JavaScript to be stored in an external file and then included into the HTML file.
HTML code
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<script src="111.js"></script>
</head>
<body>
<input type = "button" onclick = "Hello()" value = "点击" />
</body>
</html>
External js file
Summary: The above is the entire content of this article. I hope it will be helpful to everyone learning JavaScript. The above is the detailed content of How to place JS script in HTML document. For more information, please follow other related articles on the PHP Chinese website! function Hello() {
document.write("hello world")
}
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
1670
14
1428
52
1329
25
1274
29
1256
24
Python vs. JavaScript: The Learning Curve and Ease of Use
Apr 16, 2025 am 12:12 AM
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.
From C/C to JavaScript: How It All Works
Apr 14, 2025 am 12:05 AM
The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.
JavaScript and the Web: Core Functionality and Use Cases
Apr 18, 2025 am 12:19 AM
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.
JavaScript in Action: Real-World Examples and Projects
Apr 19, 2025 am 12:13 AM
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.
Understanding the JavaScript Engine: Implementation Details
Apr 17, 2025 am 12:05 AM
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 vs. JavaScript: Community, Libraries, and Resources
Apr 15, 2025 am 12:16 AM
Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.
Python vs. JavaScript: Development Environments and Tools
Apr 26, 2025 am 12:09 AM
Both Python and JavaScript's choices in development environments are important. 1) Python's development environment includes PyCharm, JupyterNotebook and Anaconda, which are suitable for data science and rapid prototyping. 2) The development environment of JavaScript includes Node.js, VSCode and Webpack, which are suitable for front-end and back-end development. Choosing the right tools according to project needs can improve development efficiency and project success rate.
The Role of C/C in JavaScript Interpreters and Compilers
Apr 20, 2025 am 12:01 AM
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.
