Angular vs. AngularJS: What’s the difference?

Key takeaways:

• Understand the shift from AngularJS’s MVC to Angular’s component-based architecture for better scalability.

• Learn TypeScript to leverage its static typing and advanced features for large projects.

• Apply Angular’s performance improvements like one-way data binding and AOT compilation for faster apps.

• Utilize Angular’s built-in tools for creating mobile-friendly, cross-platform applications.

• Explore advanced dependency injection techniques in Angular for efficient project management.

If you’ve ventured into web development, you’ve probably heard the terms Angular and AngularJS thrown around. They may sound similar, but are they two distinct JavaScript frameworks? One sparked a revolution in front-end development (i.e., AngularJS), and the other (i.e., Angular) took that revolution to the next level. So, what sets them apart? Let’s explore the key differences and discover how each framework can shape your approach to building modern web applications.

What is AngularJS?#

AngularJS is a JavaScript-based front-end framework developed by Google in 2010. It was designed to simplify building dynamic web applications by providing a well-structured framework that developers could use to manage their code. AngularJS uses the model-view-controller (MVC) architecture, allowing for a clear separation of concerns within an application. This separation makes it easier to manage complex applications by isolating the data (model), the user interface (view), and the application logic (controller).

What is Angular?#

Angular (often called Angular 2+) is a complete rewrite of AngularJS, released by Google in 2016. Unlike AngularJS, which is based on JavaScript, Angular is built using TypeScript—a superset of JavaScript that adds static typing and other advanced features. Angular was designed to address the shortcomings of AngularJS, offering a more modern, scalable, and efficient framework for building web applications.

Angular vs. AngularJS: A quick comparison#

Let’s quickly compare AngularJS and Angular across key aspects to better understand their differences.

Detailed comparison: Angular vs. AngularJS#

Let’s break down the key differences between Angular and AngularJS across various aspects:

Architecture#

• AngularJS: It follows the model-view-controller (MVC) architecture. The controller handles the business logic, the model represents the data, and the view is the user interface.

• Angular: It follows a component-based architecture, where the application is organized into modules, each containing a set of reusable components. These components define specific UI parts and are linked to templates, with services like UserService handling business logic and data interaction. Components can also interact with directives and pipes to modify their behavior or display.

Language#

• AngularJS: Developers write code in JavaScript, a language familiar to many web developers, but it lacks some advanced features beneficial for large-scale applications.

• Angular: Developed using TypeScript, an enhanced version of JavaScript that adds static typing, classes, interfaces, and other modern features, making it ideal for building scalable and maintainable applications.

Performance#

• AngularJS: Performance challenges may arise in large applications, especially when many bindings and watchers are in the scope. This framework relies on two-way data binding and the digest cycle, which constantly checks for changes.

• Angular: Optimized for better performance with features like ahead-of-time (AOT) compilationAhead-of-time (AOT) compilation is a process in which Angular compiles your application’s code during the build time, before the browser downloads and runs it. This contrasts with Just-in-time (JIT) compilation, where code is compiled in the browser at runtime., tree shakingTree shaking is a technique used in JavaScript and TypeScript bundlers (like Webpack) to optimize the final output of an application by eliminating unused code. The process gets its name from the idea of "shaking" a tree and removing the dead or unnecessary branches, leaving only the essential parts., and improved change detection mechanisms.

Angular offers superior performance and scalability compared to AngularJS, making it a better choice for modern web applications.

Mobile support#

• AngularJS: Primarily designed for desktop applications with limited support for mobile development.

• Angular: Comes with built-in support for mobile development, including tools like Angular UniversalAngular Universal is a server-side rendering (SSR) tool for Angular applications. It pre-renders the application on the server rather than in the browser, enhancing performance, SEO, and user experience. for server-side rendering and Angular CLI for streamlined project setup.

Data binding#

• AngularJS: It supports two-way data binding, where changes in the model are reflected in the view and vice versa. While this simplifies development, it can lead to performance issues in large applications due to the constant synchronization of data.

• Angular: It uses one-way data binding by default, where the data flows in a single direction from the model to the view. This approach enhances performance and makes the application easier to debug.

Dependency injection#

• AngularJS: Dependency injection is a core feature in AngularJS, making it easier to manage dependencies within an application.

• Angular: Builds on the dependency injection model introduced in AngularJS but with enhanced features, making it more powerful and flexible.

Tooling and ecosystem#

• AngularJS: It has a mature ecosystem with many third-party libraries and tools, but development has slowed as the community moves toward Angular.

• Angular: Boasts a robust ecosystem with Angular CLI, which automates many development tasks and an active community that regularly contributes to its growth.

When to use Angular vs. AngularJS#

Choosing between Angular and AngularJS depends on several factors, including the project’s requirements, the team’s familiarity with the frameworks, and the long-term goals.

Use AngularJS if:#

• We are maintaining an existing project built with AngularJS.

• The application is small to medium, where performance is not a critical concern.

• Our team is more comfortable with JavaScript and the MVC pattern.

Use Angular if:#

• We are starting a new project that requires scalability and high performance.

• The project needs to support mobile platforms.

• Our team is familiar with or willing to learn TypeScript and modern web development practices.

Conclusion#

While AngularJS was groundbreaking when it was first released, the evolution of web development has led to the creation of Angular, a more powerful and efficient framework. Angular’s modern architecture, improved performance, and scalability make it the go-to choice for most new projects. However, AngularJS still holds value, particularly in maintaining older applications. Understanding the evolution from AngularJS to Angular equips you to choose the right tool for the job. While AngularJS revolutionized early web development, Angular’s modern architecture, performance, and mobile-first design make it the go-to choice for building scalable, future-proof applications.

Explore the key concepts regarding Angular and AngularJS in more detail through our interactive courses/paths on Educative: