What tags does javascript use?-Front-end Q&A-php.cn

What tags does javascript use?

青灯夜游

Release： 2022-09-29 18:04:22

Original

3048 people have browsed it

The tag used by javascript is "<script>". JavaScript cannot run alone and can only be executed in the host environment; usually JavaScript scripts implement their functions by placing them in HTML. There are two ways to import JS into HTML: 1. Use the "<script>js code</script>" statement to embed JS code in the HTML page; 2. In HTML, introduce external JS script files through the src attribute of the script tag .

What tags does javascript use?

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

The tag used by javascript is "<script>". The </script><script> tag is used to define client-side scripts, such as JavaScript. </script>

JavaScript is a scripting language that cannot be run independently like an exe program and can only be executed in the host environment. Usually JavaScript scripts realize their functions by embedding them in HTML.

Two methods to import JavaScript into HTML documents

Method 1. Embed JavaScript code in HTML documents

To embed JavaScript scripts in HTML pages, you need to use the <script> tag. Users can directly write JavaScript code in the <script> tag. </script>

Write JavaScript code between <script></script>.

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>第一个JavaScript程序</title>
    <script type="text/javascript">
        document.write("<h1>PHP中文网：https://www.php.cn/</h1>");
    </script>
</head>
<body></body>
</html>

Copy after login

What tags does javascript use?

Method 2: Introducing external JavaScript code script files into HTML documents

JavaScript programs can not only be placed directly in HTML documents , or placed in a JavaScript script file. JavaScript script files are text files with the extension .js and can be edited using any text editor. JavaScript files can then be imported into HTML pages using the <script> tag. </p><p>Example: <br/></p><p>Write the following JavaScript code in the test.js file. </p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false">alert("PHP中文网：https://www.php.cn/");</pre><div class="contentsignin">Copy after login</div></div><p>Insert a <script> tag within the <head> tag of the HTML document. Define the src attribute and set the attribute value to a URL string pointing to an external JavaScript file. The code is as follows: </p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:html;toolbar:false"><script type="text/javascript" src="test.js"></script></pre><div class="contentsignin">Copy after login</div></div><p><img src="https://img.php.cn/upload/image/938/125/668/166444551264408What%20tags%20does%20javascript%20use?" title="166444551264408What tags does javascript use?" alt="What tags does javascript use?"></p> <blockquote>##Note: When using the <script> tag to include external JavaScript files, the default file type is Javascript. Therefore, regardless of whether the loaded file has a .js extension or not, the browser will parse it as a JavaScript script. <p></script>

Note: The <script> tag that defines the src attribute should no longer contain JavaScript code. If the code is embedded, only the external JavaScript file will be downloaded and executed, and the embedded code will be ignored. </script>

Note:

Commonly used text editors include Notepad in Windows systems, Vim, Sublime Text, Notepad, etc. in Linux systems. For beginners, it is recommended to use a text editor to write JavaScript code first, which will help us remember JavaScript syntax, keywords, functions, etc. When it comes to the actual development stage, you can choose some more professional code editors, such as Visual Studio Code (referred to as "VS Code"), WebStorm (paid), Atom, etc., which can improve development efficiency.

【Related recommendations:

javascript video tutorial, programming video】

The above is the detailed content of What tags does javascript use?. For more information, please follow other related articles on the PHP Chinese website!