Difference Between Angular and AngularJS

Angular and AngularJS are both open-source frameworks developed by Google for building web applications, but they are quite different in terms of architecture, features, and performance. Here’s a detailed comparison between Angular and AngularJS:

1. Introduction and Release

• AngularJS:
  • Released in 2010.
  • It is the first version of Angular, commonly referred to as Angular 1.x.
  • A JavaScript framework used to build single-page applications (SPAs).
• Angular:
  • Released in 2016 (version 2+).
  • A complete rewrite of AngularJS, often referred to as Angular 2+.
  • Built using TypeScript (a superset of JavaScript), and is designed to be faster, more modular, and more maintainable.

2. Language

• AngularJS:
  • Written in JavaScript.
• Angular:
  • Written in TypeScript, which is a statically-typed superset of JavaScript. TypeScript offers features like type checking, classes, interfaces, and more, making the code more robust and easier to maintain.

3. Architecture

• AngularJS:
  • Follows a Model-View-Controller (MVC) architecture.
  • The application is organized into models (data), views (UI), and controllers (logic).
• Angular:
  • Follows a Component-Based Architecture.
  • Applications are built using components (UI views and logic) and services (business logic). Components are reusable and easier to test.

4. Change Detection Mechanism

• AngularJS:
  • Uses two-way data binding and an $digest cycle for change detection.
  • AngularJS checks for changes in the model and updates the view, which can be inefficient as the app grows, leading to performance issues.
• Angular:
  • Uses unidirectional data flow and change detection strategies (like OnPush).
  • Angular uses zone.js to track asynchronous operations and trigger change detection only when necessary, resulting in better performance.

5. Performance

• AngularJS:
  • Slower performance due to two-way data binding and $digest cycles. The process of checking and updating views for every change in the model can be expensive, especially in large applications.
• Angular:
  • Much faster performance. The new architecture and unidirectional data flow lead to fewer digest cycles and a more optimized rendering process.

6. Dependency Injection (DI)

• AngularJS:
  • Dependency Injection is supported but is less powerful and flexible compared to Angular.
• Angular:
  • Angular introduces a more advanced and flexible Dependency Injection (DI) system that allows for more granular control over services and their lifetimes.

7. Routing

• AngularJS:
  • The ngRoute module was used for routing, but it was somewhat limited and lacked features found in modern frameworks.
• Angular:
  • Angular Router provides a powerful and configurable routing system, allowing for features like lazy loading, route guards, child routes, and more.

8. Mobile Support

AngularJS:

• No native mobile support.

• Angular:
  • Designed with mobile-first in mind and supports responsive designs out-of-the-box.
  • It also has features like Angular Universal for server-side rendering (SSR) and progressive web app (PWA) support.

9. Tooling and Ecosystem

• AngularJS:
  • Fewer modern tooling options.
  • Not as easy to integrate with modern build tools and workflows.
• Angular:
  • Provides a full development ecosystem with tools like Angular CLI (Command Line Interface), which makes project setup, building, testing, and deployment much easier.
  • Supports modern tooling and integrations like Webpack, ESLint, Bazel, etc.

10. Modularity

AngularJS:

• The framework is less modular, meaning you can’t easily manage or break the application into smaller, reusable units.

• Angular:
  • Built with modularity in mind. It uses modules to group components, services, pipes, and directives, making it easier to manage large applications and implement lazy loading.

11. Mobile and Desktop App Support

• AngularJS:
  • Limited support for mobile and desktop applications.
• Angular:
  • More suitable for both mobile and desktop applications with tools like Ionic and NativeScript that integrate seamlessly with Angular to build mobile apps.

12. Community and Updates

• AngularJS:
  • Since Angular 2+ has been released, AngularJS is now considered legacy and is no longer actively maintained, except for critical security updates.
• Angular:
  • Actively maintained with regular updates. It has a large community and ecosystem, offering better support and features.

13. Learning Curve

• AngularJS:
  • Easier to learn, especially for developers familiar with JavaScript.
• Angular:
  • Steeper learning curve due to its use of TypeScript and more advanced concepts like decorators, modules, services, and RxJS (Reactive Extensions for JavaScript).

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Key Differences Summary

Feature	AngularJS	Angular
Release Year	2010	2016 (Rewrite of AngularJS)
Language	JavaScript	TypeScript (superset of JavaScript)
Architecture	MVC (Model-View-Controller)	Component-Based Architecture
Data Binding	Two-way data binding	Unidirectional data flow (one-way)
Performance	Slower, due to digest cycles	Faster, due to optimized change detection
Dependency Injection	Less flexible	Advanced and flexible DI system
Routing	ngRoute (limited)	Angular Router (powerful, configurable)
Mobile Support	No native support	Built with mobile-first in mind
CLI/Tooling	Limited tooling	Angular CLI, modern build tools
Community Support	Legacy (no active updates)	Actively maintained and updated
Learning Curve	Easier to learn	Steeper learning curve, especially with TypeScript
Use Case	Smaller applications, quick prototypes	Scalable, production-ready applications

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Conclusion:

• AngularJS is the older version of the framework, now considered legacy, while Angular (2+) is the modern, fully updated version.
• Angular is more powerful, modular, and efficient compared to AngularJS. If you’re starting a new project or maintaining an existing one, Angular is the recommended framework for modern web development.