Major Differences Between: AngularJS vs. Angular 2 Vs. Angular 4
Angular is an open-source, JavaScript framework written in TypeScript. Google maintains it and provides a standard structure for developers to work within it.

The technologies that enable the Internet tend to change, progress, and evolve at rapid speeds, as requirements change and developers build better versions of the software. Angular is a case in point, with wide changes in just a few years. Google developed AngularJS in 2009 and version 1.0 was released in 2012. Angular has since dominated the world of open-source JavaScript frameworks, with enthusiastic support and widespread adoption among both enterprises and individuals. As a result, Angular has evolved from AngularJS version 1.0 to Angular version 2.0 and now the latest Angular version 4.0, all in just five years.
Despite the potential benefits of the upgrades, some in the Angular community have concerns about migrating to a newer version. Keep reading to find out what has changed in Angular and why migrating to the latest version is a good idea.
What is Angular?
Angular is an open-source, JavaScript framework written in TypeScript. Google maintains it and provides a standard structure for developers to work within it. Angular makes use of HTML syntax to define the components of your program clearly. It enables developers to build large applications in a maintainable manner.
Types of Angular Versions
Before we dive into the differences, let’s first clarify each angular version with a description:
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AngularJS
is an open-source, JavaScript-based, front-end web application framework for dynamic web app development. It utilizes HTML as a template language. By extending HTML attributes with directives and binding data to HTML with expressions, AngularJS creates an environment that is readable, extraordinarily expressive and quick to develop. -
Angular 2
is the blanket term used to refer to Angular 2, Angular 4, and all other versions that come after AngularJS. Both Angular 2 and 4 are open-source, TypeScript-based front-end web application platforms. -
Angular 4
is the latest version of Angular. Although Angular 2 was a complete rewrite of AngularJS, there are no major differences between Angular 2 and Angular 4. Angular 4 is only an improvement and is backward compatible with Angular 2.
Components of Angular vs AngularJS
The main difference between a JavaScript-based framework and a TypeScript one can be seen in their components. Angular uses TypeScript and has components as its main building blocks. It is component-based, whereas AngularJS uses directives.
Angular's operation employs a hierarchy of components, while AngularJS has directives that allow code reusability. So, The AngularJS framework provides reusable components for its users. AngularJS also uses controllers and scopes. Although Angular has standard directives, the two frameworks implement them differently.
The Angular components play a significant role in creating user interfaces where every UI portion is defined as a component. In AngularJs, the same task is done using component directives. AngularJS component directive can be migrated to Angular with a few configurations.
Use of Directives Between Angular vs AngularJS
Angular includes standard directives, and AngularJS contains a pack of them. So, both AngularJS and Angular use directives, but they use them differently. For instance, one can use the ng-model to create a two-way binding in AngularJS. The ng-bind directive is suitable for one-way binding.
Contrastingly, Angular has only the ngModel. Using symbols, one can specify the type of binding: one-way binding as:" []," and two-way binding as:" [()]." "()" is for event binding, and "[]" is for property binding.
Below is a comparison of AngularJS to Angular, because Angular includes both version 2 and version 4. We compare architecture, language, expression syntax, mobile support, and routing.
The architecture of AngularJS is based on the model-view-controller (MVC) design. The model is the central component that expresses the application's behavior and manages its data, logic, and rules. The view generates an output based on the information in the model. The controller accepts input, converts it into commands, and sends the commands to the model and the view.
Angular uses components and directives. Components are directives with a template.
In Angular 2, controllers and $scope were replaced by components and directives. Components are directives with a template. They deal with a view of the application and logic on the page. There are two kinds of directives in Angular 2. These are structural directives that alter the layout of the DOM by removing and replacing its elements, and attributive directives that change the behavior or appearance of a DOM element.
In Angular 4, the structural derivatives ngIf and ngFor have been improved, and you can use if/else design syntax in your templates.
AngularJS is written in JavaScript.
Angular uses Microsoft’s TypeScript language, which is a superset of JavaScript. This has advantages like type declarations, and the benefits of ES6, like iterators and lambdas
Angular 4 is compatible with the most recent versions of TypeScript that have powerful type checking and object-oriented features.
To bind an image/property or an event with AngularJS, you have to remember the right ng directive.
Angular focuses on “( )” for event binding and “[ ]” for property binding.
AngularJS was not built with mobile support in mind, but Angular, Angular 2 and 4 feature mobile support.
AngularJS uses $routeprovider.when() to configure routing while Angular uses @RouteConfig{(…)}.
AngularJS was originally developed for designers, not developers. Although there were a few evolutionary improvements in its design, they were not enough to fulfill developer requirements. The later versions, Angular 2 and Angular 4, have been upgraded to provide an overall improvement in performance, especially in speed and dependency injection.
By providing features like 2-way binding, AngularJS reduced the development effort and time. However, by creating more processing on the client-side, page load was taking considerable time. Angular2 provides a better structure to more easily create and maintain big applications and a better change detection mechanism. Angular 4 is the fastest version yet.
Angular implements unidirectional tree-based change detection and uses the Hierarchical Dependency Injection system. This significantly boosts the performance for the framework.
Because they are Google products, all Angular versions are trustworthy and enjoy great support from Google engineers and the large community of Angular users and developers. However, each angular version has its own advantages and disadvantages.
Why Angular?
Why AngularJS?
Difference Between AngularJs and Angular Versions
1. Architecture
AngularJS
Angular
Angular 2
2. Language
AngularJS
Angular versions
3. Expression Syntax
AngularJS
Angular versions
4. Mobile Support
5. Routing
6. Performance
Speed
Dependency Injection
Advantages and Disadvantages of AngularJs and Angular Versions
1. AngularJS
Advantages
Disadvantages
2. Angular 2
Advantages
Disadvantages
3. Angular 4
Advantages
Disadvantages