When you write JavaScript, you should write them in a JavaScript file that ends with a .js extension. These
JavaScript files can be named anything you want. Most people name their first JavaScript file either app.js
or main.js
Then, to link a JavaScript file to HTML you should use <script> tag with the src attribute pointing to the
JavaScript file. Place this tag before </body> tag.
<body><!-- Content --><script src="js/main.js"></script></body>Ensure the JavaScript file linked properly by adding this alert() function to your JavaScript file. if the link is
correct, you’ll see a prompt when you open your index.html in a browser. Afterwards, remove this alert code.
alert('Your JavaScript is linked')JavaScript Placement in HTML
It’s not recommended to add your JavaScript file within the <head> tag, as it can delay HTML and CSS display. if
needed, use the async attribute.
<head> <meta charset="utf-8"/> <title>Title of website</title> <script src="js/main.js"></script> <script src="js/main.js" async></script></head>Relative and Absolute Paths
Use a relative path to link your JavaScript file, starting with the file name or folder. Absolute paths start
with a / or an HTTP protocol and are used for external resources like jQuery
<!--- Relative path --><script src="js/main.js"></script>
<!-- Absolute path--><script src="<HTTP protocol target to jquery file>"></script>