What Is Javascript?


When you click on a link or a button, the page behind that link will be loaded and parsed by your browser using javascript. This scripting language is used to make the pages interactive and add features such as animation, pop-up menus, clickable buttons, real time chat and much more. It is a client-side programming language that is fully integrated with HTML and CSS. Without javascript, web pages would be completely static and uninteresting.

javascript is an object-oriented language and it uses inheritance to allow code to share functionality between functions. Unlike many other languages, javascript is not a compiled language but interpreted, which means that the javascript engine converts the code to machine code as it’s executed (this process is called just-in-time compilation). This allows for very fast processing of simple functions and processes. Other languages use ahead-of-time compilers, which are slower.

The javascript engine also has its own built in libraries for data structures, collections, string handling and more. There are many other third party libraries available, including those that are very specific to the needs of a particular website or application. This makes javascript very versatile and open to use.

This scripting language is also used to make the communication between a server side program and the user’s machine more efficient, as it reduces the amount of information transferred over the internet between the two programs. This is especially important for websites that serve large amounts of data, such as search engines or social media sites.

While javascript is a powerful language, it can be used to create malware, viruses and browser hacks that can steal user data such as passwords and credit cards or download malicious software on the user’s computer. This is why it is very important to take precautions and limit the number of javascript scripts on any given webpage, and only include those that are necessary for the functioning of the site.

Another issue is that the more javascript that is on a webpage, the more it will affect performance. Your browser will need to download, parse and execute each jscript script in order of their appearance within the HTML, which can be a lengthy process. To increase site performance, jscripts should be placed inside an async> or defer> tag so that they are only loaded and executed once all the other scripts on the page have been loaded and parsed.

A good practice is to put the “must-have” jscripts in the head of the document and place “nice-to-have” scripts in the body of the page. You can also utilize a combination of both, placing the most important scripts at the beginning of the document and the “nice-to-have” scripts at the end. This will give the page a more consistent performance and speed.