What Is JavaScript and How Does It Work?
Along with hypertext markup language (HTML) and cascading style sheets (CSS), javascript is one of the most important elements in web development. It is what makes websites dynamic and interactive and gives them functionality that wouldn’t otherwise be possible without it. But what exactly is javascript and how does it work?
The jQuery library is a popular JS framework that developers use to make their own web applications. It lets them add things like animation, pop-up windows, form validation, and chat widgets to their websites. It is also used to create real-time content updates that can be displayed on a webpage without having to reload the entire page. In fact, most front end web sites are built on javascript.
When you visit a website, the computer that stores the site sends a bunch of files to your computer (the server). These include HTML and CSS and, depending on the site, some javascript. These files are what display the website on your screen. But what happens behind the scenes to make the magic happen?
During this process, the code is parsed and compiled into machine code. This is done by the JavaScript engine, which is a program on your computer. It contains a call stack and heap, which are both memory pools where the code is executed. The JavaScript engine uses the execution context to execute the code and access the DOM. The DOM is an element family tree where the browser can find and modify elements on a webpage.
JavaScript is a high-level language, which means that it’s easy for human beings to read and understand. It’s also been around in some form for more than three decades, so it’s well established and has lots of support and resources available. This helps to speed up the process of learning it and making mistakes. Plus, it can be directly typed into an HTML document without needing to be compiled, which is pretty convenient.
Another useful feature of javascript is that it can be manipulated with functions. For instance, a number can be converted to a string by using the toString and valueOf functions. This is a handy way to avoid having to do the math in your head or typing out long strings of numbers. JS is also able to do things like inlining, which is when the engine replaces function calls with the actual code of the function. This is a great way to save on space and improve performance.
There are other things that javascript can do but these are the main ones. It is used for almost all front end web development and it’s often combined with back end web services and tools to help provide features such as analytics, event tracking, and ads. It’s also used in many other areas such as mobile and desktop applications. It’s a powerful programming language that is used to do all kinds of cool stuff. So if you’re looking to learn more about web development, it’s definitely worth learning javascript.