.JS File Extension
What is a JS file?
A JS file is a plain text file that contains JavaScript code. It is used to execute JavaScript instructions in a webpage. JS files may include functions that open and close windows, validate form fields, enable rollover images, or create dropdown menus.
Web developers use JavaScript to add dynamic and interactive elements to webpages. One of the ways developers can add JavaScript functions to a webpage is by importing them using a JS file.
Developers usually import JS files in the <head> or <body> sections of a webpage's HTML, as shown below:
<head> <script type="text/javascript" src="FileInfo.comExample.js"></script> </head>
JS files often contain standard or site-wide functions that a developer wants to include on each of a site's webpages. Storing the functions in a single, importable JS file makes them easier to maintain and troubleshoot.
How to open a JS file
You can open and edit a JS file in any text or source code editor. Source code editors, such as Microsoft Visual Studio Code and GitHub Atom contain helpful syntax-highlighting and code-editing tools that make reading and editing JS files easier.