As one of the most in-demand IT skills in 2020, JavaScript developers play an important role in software development.
Developers use multiple programming languages to turn visions and plans into functional, attractive websites and applications. JavaScript is fundamental to this process, as it is used to create responsive and interactive web page elements that significantly improve the user experience. It is so effective that over 95% of websites use it to enable dynamic content.
Given the fundamental role of JavaScript in front-end web development, companies often look for developers with experience in this language. According to a report by DevSkiller, a developer skills tester, JavaScript is themost in-demand IT skill for 2020 and approximately 72% of companies are looking for JavaScript developers.
Java versus JavaScript
Despite the similar names, JavaScript is not the same as Java. Java, currently the third most popular programming language after JavaScript and Python, runs on one billion devices as part of Google's Android operating system. Released by Sun Microsystems in 1995, Java is now owned by Oracle. It is commonly used for credit card programming, Android apps, desktop apps, and enterprise-level apps.
JavaScript was created by a Netscape developer in the early 1990s. It began as a programming language that could direct a computer to interpret user commands without the need for plug-ins or code compilation. The language was initially called “LiveScript” and added to Netscape Navigator. It was later renamed “JavaScript” to take advantage of the growing popularity of Java at the time.
Similarities:
- Both are object-oriented languages that use “objects” to represent data and methods, as opposed to procedural programming with a list of instructions.
- Both can be used in front-end and server-side development.
Differences:
- Languages are assembled, written and executed differently.
- JavaScript is all text code, while Java code must be compiled.
- JavaScript is weakly typed (variables are not tied to a specific data type), while Java is strongly typed (requiring developers to define code variables with data type restrictions).
- Languages use different plugins.
- JavaScript runs only in a browser, while Java creates applications that run in a Java virtual machine or a browser.
- JavaScript is more involved on the client side, while Java is typically used for server-side functionality.
Front-End Web Development
Front-end web developers use JavaScript, in combination with HTML and CSS, to build the visible parts of websites and applications that users interact with on a phone, tablet, or computer.
Hypertext Markup Language (HTML) is used to format and organize web pages. It is responsible for the structure of the website and allows content in the form of text, images, links and videos. CSS is used to style the content that HTML inserts into web pages. It defines shapes, sizes, colors and fonts, controlling the appearance of the web page.
JavaScript is the scripting language that developers use to create and control dynamic content and transform web elements into interactive resources. It's involved with everything that updates itself, like interactive forms, autocomplete features, and animated menus, and allows new content to load automatically as users navigate through the site.
Additional features produced by JavaScript include:
- Forms with error checking input fields to ensure users enter correct and complete information in all required fields
- Animated images
- Personalized greetings based on time of day
- Interactive maps
JavaScript developers can add a wide range of useful functionality to websites, as described in the following video:
Back-end web development and other uses
Although JavaScript is primarily involved in front-end web development, it has other uses. Developers use some forms of JavaScript, such as Node JS, in back-end development. In this case, it builds and maintains the infrastructure that allows websites and applications to function.
Node JS is an open source runtime environment that processes server-side code and helps run a program. It increases speed by using server idle time and an event loop to complete requests.
JavaScript is also part of Android and iOS, Desktop and Hybrid systems. These uses are possible because JavaScript engines—interpreters that convert JavaScript code into machine code that a CPU can execute—are written in C++ and can be incorporated into any C++ application.
Additional Final Products
Although JavaScript's main product is interactive and dynamic websites, developers also use it in other aspects of web development and to create games, web and mobile applications, web servers, and web-based slideshows.
Web development
In addition to front-end development features like interactive forms and animation, JavaScript allows users to upload content to a website without having to reload the entire page. It also supports external web applications like Flash, PDF and widgets.
Games
Developers can use JavaScript with HTML5 to create interactive games with complex graphics and animations that only require a keyboard to play. Libraries like Ease JS offer solutions for working with game graphics and allow developers to integrate multiple images into one, reducing server requests and bandwidth requirements. These actions speed up the game.
Mobile apps
Developers can use JavaScript to create cross-platform mobile apps for iOS, Android, Windows, and Blackberry that load content quickly and support a variety of screen sizes and resolutions. Frameworks, like React Native, that enable this functionality are typically open source and served by support communities that provide documentation and resources to assist developers.
Web Applications
Because JavaScript can interact directly with browsers rather than sending messages through servers, it allows developers to create faster web applications. When developers use application programming interfaces (APIs) with JavaScript, they add functionality and performance. With APIs, applications request only the specific data they need, avoiding storing unnecessary fields.
Web servers
Developers can use JavaScript to create web servers using the Node JS framework. This approach is event-driven, so this type of web server is very fast in moving on to the next task without transferring large amounts of data. Commands are executed individually in single-threaded processes, which reduces the number of errors.
Web-based slideshows
Developers can use JS libraries such as Reveal JS and Bespoke JS to create interactive web-based slideshows. Users can add images and elements like bulleted lists, and swipeable platforms provide responsive scaling to adapt to use on desktops, mobile devices, and tablets.
JavaScript developers are in high demand
It's not surprising that JavaScript developers are in such high demand, given that businesses and individuals expect the responsive, interactive web page elements that this language makes possible. The need for this level of interactivity will likely continue, so the demand for JavaScript developers isn't likely to diminish anytime soon.
Source: BairesDev
