We make it easy to hire people online. Get a money-back guarantee, awesome workspace, clear terms in plain English, upfront bills with itemized PDF receipts.
All purchases (except Tips) are subject to a non-refundable Handling Fee of $3.49. This pays for platform overheads including admin, hosting, marketing, data costs and 24×7×365 support.
Add interactivity and dynamic graphics to your website. Start with simple scripts in vanilla JavaScript and gradually proceed to complex applications; Build dynamic web applications with React and Node.js, learn how to handle pre-made JavaScripts (slideshows, tabbed panels, etc.); create APIs with Express.js, and work with databases with MongoDB. Browser Application Programming Interfaces (APIs) built into web browsers, providing functionality such as dynamically creating HTML and setting CSS. Got a JavaScript (JS) project? Hire the best JavaScript (JS) freelancers with the right skills and background in April 2025 to get your JavaScript (JS) job done quickly. Schedule a consultation with a JavaScript (JS) freelancer today. Read less
JavaScript (JS) is a versatile, high-level, interpreted programming language that is fundamental to web development. Initially designed to make web pages interactive, JavaScript has evolved into a powerful language capable of running not only in browsers but also on servers (with Node.js), in mobile applications, and on IoT devices. It's known for its dynamic typing, first-class functions, and prototype-based object-orientation. JavaScript's ability to manipulate the Document Object Model (DOM) in browsers makes it pivotal for creating dynamic, interactive web experiences.
How JavaScript Works:
Client-Side Execution: In web browsers, JavaScript runs client-side, executing scripts embedded within or linked to HTML. It interacts with the DOM to change page content, style, and behavior in response to user actions or events.
Event-Driven: JavaScript uses an event loop to manage asynchronous operations, allowing the browser to remain responsive while waiting for operations like network requests or timers.
Compilation to Bytecode: Modern browsers compile JavaScript into bytecode and then to machine code at runtime, optimizing performance through just-in-time compilation.
Server-Side with Node.js: On the server, JavaScript runs on Node.js, which uses Google's V8 engine to execute JS outside the browser, enabling full-stack JavaScript development.
Asynchronous Programming: JavaScript handles asynchrony through callbacks, promises, and more recently, async/await syntax, allowing for non-blocking operations.
Applications Freelance Programmers Can Build Using JavaScript:
Web Applications: From simple websites to complex Single Page Applications (SPAs) using frameworks like React, Vue.js, or Angular.
Progressive Web Apps (PWAs): Apps that work offline, load quickly, and look like native apps on mobile devices.
Server-Side Applications: With Node.js, freelancers can develop backend services, APIs, microservices, or even real-time applications like chat servers.
Mobile Applications: Using frameworks like React Native or Ionic, JavaScript can be used to build cross-platform mobile apps.
Desktop Applications: Tools like Electron allow developers to create desktop applications with web technologies.
Games: JavaScript, particularly with libraries like Phaser, can be used to develop browser-based games.
IoT and Robotics: With Node.js, JavaScript can control hardware through GPIO on single-board computers like Raspberry Pi.
Principles of JavaScript:
Dynamic Typing: Variables do not have to be explicitly typed, providing flexibility but requiring careful handling to avoid type-related errors.
First-Class Functions: Functions are treated as objects, allowing for higher-order functions, closures, and functional programming paradigms.
Prototype-Based Inheritance: Unlike classical inheritance, JavaScript uses prototypes for object creation and extension.
Event-Driven and Asynchronous: Designed for handling user interactions and managing asynchronous operations effectively.
Scope and Closures: JavaScript has function scope and lexical scoping, which can lead to closures, a powerful but sometimes misunderstood feature.
DOM Manipulation: The ability to interact with and change web page elements dynamically.
Error Handling: With try/catch blocks, JavaScript allows for graceful handling of errors in asynchronous code.
Software Examples of What JavaScript Can Build:
Slack: Uses JavaScript extensively for its UI and backend services.
Netflix: Employs JavaScript for its web player and user interface.
Trello: Built using JavaScript for both frontend and backend with Node.js.
Atom: An open-source text editor built with Electron, showcasing desktop application capabilities.
Lichess: A free online chess game developed in Scala on the server but with a JavaScript client.
Resources:
Mozilla Developer Network (MDN): Offers comprehensive documentation on JavaScript, including tutorials and references.
JavaScript.info: Provides an in-depth tutorial on modern JavaScript from basics to advanced topics.
Eloquent JavaScript by Marijn Haverbeke - A book that's both a tutorial and a narrative on learning JavaScript.
Node.js Official Website: For learning server-side JavaScript.
Coursera, Udemy, FreeCodeCamp: Platforms with courses from beginner to expert levels on JavaScript and its ecosystems.
JS Weekly: A newsletter for staying updated on JavaScript developments.
Stack Overflow: Community-driven Q&A for troubleshooting and learning from real-world scenarios.
GitHub: Repositories like those for React, Vue, or Node.js projects provide practical examples of JavaScript in use.
JavaScript's ubiquity and versatility make it an indispensable skill for freelance programmers, offering opportunities to work on diverse projects from simple scripts to complex, scalable applications. Its ecosystem of libraries and frameworks continues to grow, ensuring that developers have tools for virtually any programming task they might encounter.
