How to use JavaScript code? How to introduce HTML page?-JS Tutorial-php.cn

How to use JavaScript code? How to introduce HTML page?

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Release： 2022-04-02 19:37:10

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How to use JavaScript code? How to introduce HTML page? The following article will introduce to you two ways of writing JavaScript code into HTML pages. I hope it will be helpful to you.

How to use JavaScript code? How to introduce HTML page?

#Before learning JavaScript, we should first understand how to use JavaScript code? Let's take a look at the usage of js code.

We use JavaScript code in two ways: One is to embed js code directly in the HTML page, and the other is to link to external JavaScript files.

Let’s look at the first usage first: directly embedding js code in the HTML page

If we embed the JavaScript code directly in the HTML page, we need Using the <script> tag, <script> and </script> tells JavaScript where to start and end.

You may see type="text/javascript" used in the <script> tag, but this is no longer necessary. JavaScript is now the default scripting language in all modern browsers as well as in HTML5. </p> <p>Let’s look at a specific example</p> <p><div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:js;toolbar:false"><script> alert("My First JavaScript"); </script></pre><div class="contentsignin">Copy after login</div></div><br/>The above code is to embed js code directly in the HTML page. </p><p>Then let’s take a look at the </p><p> second usage of <strong>js code: by linking to external JavaScript files. </strong><strong></strong>Sometimes if there are too many JavaScript codes, we can put the codes separately in JavaScript files and link them together. </p><p>We can follow the following steps to link external JavaScript files</p><p><br/>1. First, we create a JavaScript file with an extension of .js</p><p>2. Then we will write The js code is written into the Js file and the file is saved. </p><p>3. Use the script tag to link the JavaScript file to the HTML file</p><p><script type="text/javascript" src="JavaScript file name and path"></script>

One thing to note is that in a script tag that has introduced an external js file, you cannot write Js commands in its start tag and end tag.

Let’s look at a specific example

We first create a js file sample.js

Then write the js code

<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script>
document.write("<h1>This is a heading</h1>");
document.write("<p>This is a paragraph</p>");
</script>
</body>
</html>

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Finally Use script tags to link JavaScript files to HTML files

document.write("<p>This is a paragraph</p>");

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The above are the two methods used by js code

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