What is Javascript?


If you work with technology at all, you’ve probably heard of javascript. It’s a programming language that is used for creating dynamic web applications and mobile apps. The good news is, it’s not as hard to learn as it sounds and it can help you create some pretty awesome things.

The best way to understand javascript is by looking at some examples. For example, when you’re on Facebook and see that someone has posted something new on their timeline or when you do a search in Google and it suggests search terms based on the letters you’ve started typing, that is all made possible by javascript.

You can also use javascript to add interactivity to your websites. Adding a little javascript can improve user experience and it can also help you to boost your website’s search engine rankings. However, too much javascript can make your site load slowly which can be frustrating for your users and it can even cause them to leave your website altogether.

Javascript is a scripting language which is designed to run in a host environment, the most common of which is the web browser. The language is interpreted by the host environment which then executes it using an engine called a JS virtual machine. This is usually done in the browser although it can also be performed on a server or even embedded within a device.

The language is designed to be a general purpose, object-oriented programming language and it supports both imperative and functional programming styles. It also supports a number of object-oriented features such as inheritance, polymorphism, and encapsulation. The language can be extended by incorporating various libraries and it has built-in functions that provide standard functionality like string manipulation, math operations, date and time calculations and string concatenation.

As with all languages, javascript has its own syntax and idioms. A few of these include the if, for and while statements as well as the elif, else and try/catch statement. Functions are usually declared with the keyword function followed by an open parenthesis and a closing parenthesis. They can take 0 or more parameters and can return a value at any point, terminating the function. Functions can be nested within other functions to achieve more complex logic.

A few other important syntax features of javascript are the + operator which performs string concatenation instead of number addition, and the template literal syntax that allows you to write strings with embedded expressions more succinctly. Functions can also have default parameter syntax that allows omitted or undefined parameters to be set to a default value and there is a special function expression syntax for anonymous functions.

The popularity of javascript has helped to spur the development of a number of libraries and frameworks. There is also a renaissance in the language as developers seek to incorporate it into more modern front-end technologies that allow them to build dynamic web applications. One of these is Ajax which is a series of technologies that enable data to be loaded without requiring a full page reload.