Object-oriented (OO) languages usually are recognized through their use of classes for creating various objects which have similar properties and methods. Engineering Production-Grade Shiny Apps Sams . This Introduction to JavaScript is a JavaScript online course with a certificate that will thoroughly introduce you to JavaScript and walk you through the concepts like variables, arrays, functions, loops, and more. Before you continue you should have a basic understanding of the following: If you want to study these subjects first, find the tutorials on our Home page. One can write them in the HTML of a web page, then it will automatically run once the page loads. Hypertext defines the link between the web pages. JavaScript can dynamically modify an HTML page JavaScript can react to user input JavaScript can validate user input JavaScript can be used to create cookies (yum!) Earlier, JavaScript was named LiveScript, but later, Netscape changed its name to JavaScript because its origin was from Java which was very popular at that time. Here are some examples of what JavaScript can do: The HTML