JavaScript Where To
To use an external script, put the name of the script file in the src (source) attribute of a <script> tag:
<script src="myScript.js"></script>
JavaScript Functions
A JavaScript function is a block of JavaScript code, that can be executed when "called" for. For example, a function can be called when an eventoccurs, like when the user clicks a button.
External References
External scripts can be referenced with a full URL or with a path relative to the current web page. • Full url: <scriptsrc="https://www.w3schools.com/js/myScript1.js"></script> • This example uses a script located in a specified folder on the current web site: <script src="/js/myScript1.js"></script> • This example links to a script located in the same folder as the current page: <script src="myScript1.js"></script>
The <script> Tag
In HTML, JavaScript code must be inserted between <script> and </script> tags. <script> document.getElementById("demo").innerHTML = "My First JavaScript"; </script> **//** Old JavaScript examples may use a type attribute: <script type="text/javascript">. The type attribute is not required. JavaScript is the default scripting language in HTML.
External JavaScript
Scripts can also be placed in external files: External file: myScript.js function myFunction() { document.getElementById("demo").innerHTML = "Paragraph changed."; }
JavaScript in <head> or <body>
You can place any number of scripts in an HTML document. Scripts can be placed in the <body>, or in the <head> section of an HTML page, or in both. Placing scripts at the bottom of the <body> element improves the display speed, because script compilation slows down the display.
External JavaScript Advantages
• It separates HTML and code. • It makes HTML and JavaScript easier to read and maintain • Cached JavaScript files can speed up page loads • To add several script files to one page - use several script tags: <script src="myScript1.js"></script> <script src="myScript2.js"></script>