AngularJS Vs. Angular 2 Vs. Angular 4

It is really tough to decide which framework to choose for developing dynamic web and mobile applications. Before moving into the comparison among AngularJS, Angular 2, and Angular 4, let’s first know ‘What is Angularjs?,’ ‘What are its various versions?’ and their features and drawbacks. 

What is AngularJS?

AngularJS is also referred to as Angular 1, which is an open-source JavaScript framework. This framework is designed to build single-page applications. It overcomes the downside of HTML and also makes the best practice of libraries.

Following are some of the features of AngularJS:

• Model-View-Controller: AngularJS supports the MVC architecture that makes it easy for developers to design client-side web applications.
• Data model binding: There is no need for writing code to bind data to HTML. This will be done by adding a few code snippets by Angular.
• Requires less code: Before Angular, there was a need for a lot of JavaScript code for Document Object Model (DOM) manipulation for developing an application. Angular requires lesser code for DOM manipulation.
• Unit testing: Earlier, it was time taking to perform testing for each component of an application. In AngularJS, the testing process is very simple. It uses dependency injection to connect with the application that manages and controls everything with simplicity.

Following are some of the pros and cons of AngularJS.

Pros:

• AngularJS supports both unit testing and integration testing.
• It provides a routing facility, which is making a move from one view to another.
• It provides two-way binding, which keeps the presentation layer and data in sync.
• It provides directives that help the functionality of HTML elements, which provide more power to a web application.

Cons:

• AngularJS is less secure because it doesn’t provide server authentication and authorization.
• It might lead to a memory leak, which causes various issues such as high latency, crashing, and slowing down of the process.
• It has various ways to perform the same task, so it is hard to predict which is the best way to perform the task.
• It is not supported everywhere, and it is totally based on JavaScript.

 What is Angular 2?

Angular 2 (Angular) is a complete remake of the original AngularJS. It was rebuilt from scratch using TypeScript by the Angular team, keeping in mind the concept of having components with better performance and improved features that would help Web Developers. 

Following are some of the features of Angular2:

• TypeScript: TypeScript is the superset of JavaScript that allows an increase in code efficiency by using the OOPs concept.
• Components: Angular 2 focusses on components over controllers, which helps in efficiently maintaining applications within a period of time.
• Services: It provides a set of code (services) that could be shared by various components of the applications.
• Cross-platform: With Angular, we can build and run applications on desktops, iOS, and Android systems.

Following are some of the pros and cons of Angular 2.

Pros:

• Angular 2 provides simpler routing, and it is mobile-oriented.
• It provides various languages to choose from, such as TypeScript, Dart, ES6, and ES5.
• It has enhanced modularity and dependency injection.

Cons: 

• Angular 2 is tough to set up when compared to AngularJS.
• It is not effective in building small and simple web applications.

What is Angular 4?

Angular 4 is the rewritten version of AngularJS, which is quite different from Angular 2. It has a few minor changes, along with some newly added features to it. Angular 4 also supports TypeScript, compatible with JavaScript, which gives the same output.

Following are some of the key features of Angular 4:

• Faster and smaller: In this version, programs run quicker than in the older versions and use less space.
• Animation package: This feature helps us find docs easily and acquire the advantage of auto-completion by importing the @angular/platform-browser/animations package.
• Angular Universal: The greater part of the universal code is located in the new renderModuleFactory method in the @angular/platform server that consists of many code samples and documentation.
• Compatibility of TypeScript 2.1 and 2.2: The Angular team has enhanced the TypeScript version, which offers better type checking throughout the program.

Following are some of the pros and cons of Angular 4.

Pros:

• It allows faster application development processes and also easy-to-write tests.
• It provides a modular animation package.
• It is used for single-page web applications with an improved view engine.
• It supports TypeScript and also helps in developing large applications.

Cons:

• The processing is slow when displaying a huge amount of data.
• Testing is challenging in Angular 4.
• It doesn’t support the older versions of browsers.
• It is difficult to maintain server templating.

As we have come to know about ‘What is Angular?’ and their versions, now, let’s dive into the discussion on ‘Angular vs AngularJS,’ ‘Angular 2 vs Angular 4,’ and ‘AngularJS vs Angular4.’

Differences Between AngularJS and Angular 2

Here is the comparison between Angular 2 and AngularJS based on mobile support, functions, and architecture.

Angular 2	AngularJS
Released in 2016	Released in 2010
Follows a component-service architecture Service/Control architecture	Follows Model-View-Controller (MVC) architecture
Was created to build mobile-based applications	Was created to build web-based applications
Runs on both server-side and client-side	Runs only on client-side
To initialize bootstrap, the module() function is used	To initialize AngularJS bootstrap, ng-app functions are used

Difference Between Angular 2 and Angular 4

Below are some of the differences between Angular and Angular 4 versions:

Angular 2	Angular 4
The size of a file generated by Angular 2 is large, hence the performance is slow	The size of a file generated by Angular 4 is reduced by 60% so that the performance is fast
The animation package is not present	The animation package is present
Angular 2 is compatible with TypeScript and Dart	Angular 4 is compatible with the enhanced versions of TypeScript 2.1 and TypeScript 2.2
It doesn’t have a specific phase to adjust code	It has a proper phase to adjust code for developers
Instance scope controller is present	Instance scope controller is not present

AngularJS vs Angular 2 vs Angular 4: A Complete Comparison

Parameters	AngularJS	Angular 2	Angular 4
Origin	It is an open-source front-end framework used for developing dynamic web apps	Angular 2 is an open-source front-end web application framework	Angular 4, an enhanced version of AngularJS, is an open-source web application platform
Architecture	AngularJS follows the Model-View-Controller architecture	Angular 2 is based-on the component-service architecture	Angular 4 is based on structural-directives
Language used	AngularJS uses JavaScript	Angular 2 uses Microsoft’s TypeScript	Angular 4 uses the latest versions of TypeScript
Expression syntax	In AngularJS, we need to remember the accurate ng directive to add images, property, and events	Angular 2 follows parentheses () for event binding and square brackets [] for property binding	Angular 4 follows advanced syntax, i.e., ngIf and ngFor directives
Performance	Slow performance	Faster performance	Improved performance by dependency injection
Routing	The $routeProvider.when() method is used for routing configuration	@RouterConfig{(….)} is used by Angular 2 for routing configuration	It uses two routing methods: RouterModuleforRoot () and RouterModuleforChild ()