What Is JavaScript?


In the tech world, it’s hard to go anywhere without a run-in with javascript. The coding language is the backbone for everything from animation on Web pages to file upload forms and chat widgets that let you communicate in real-time with others. It also powers e-commerce shopping carts and allows developers to make websites that update with the latest stock or crypto prices, news and more.

Developed in the 1990s for Netscape’s Navigator browser, javascript is a client-side scripting language that enables dynamic and interactive content on Web pages. It also enables features like form validation, adaptive layouts and animation that have become a hallmark of the Internet.

It is considered a lightweight programming language because it uses less CPU resources than other languages and has minimalist syntax, making it easier to learn. It executes directly within a Web browser, allowing for a faster experience than server-side languages that must be downloaded and compiled first. JavaScript is also more portable than other languages, able to run across all major Web browsers with little or no modification.

Because of its versatility and popularity, JavaScript is an important tool for Web developers to have in their arsenals. It is especially useful for enabling the functionality of online forms that collect user data such as age, gender and email address. Web designers can use javascript to validate the entered information, ensuring that the field’s entries are valid and will function properly on various Web browsers.

JavaScript is a dynamic programming language that supports Math calculations, allows you to add HTML contents and style declarations to the DOM on a fly, fetches contents from another website and more. It is what allows you to type a text into a search box on a Web page and have it instantly display on the screen, without the need for any plugins.

It is also used to enable other interactive functions that a Web page might need such as animations, buttons and pop-up windows or audio and video players. For example, the chat widget on Twitter or Facebook and the “search” bar in Google are both examples of JS. It also lets developers include live feeds of current stock or crypto prices and real-time weather reports on their Web pages.

A key feature of javascript is its support for closures. A closure is a function that has been called but not yet completed and can be referenced in another function later on. For example, in the code below, the outer function is defined and then the inner function is called. The result of the inner function is returned to the outer function, but it’s retained in a variable called inner_closure_function that can be called later on.

Although you can build a Web application by using vanilla javascript alone, many developers find it much easier to work with coding libraries and frameworks that provide a set of functions already coded for them. These tools can speed up development time and help to prevent coding errors.