Top Angular 2 Interview Questions and Answers - Essential Guide for Job Seekers
To survive in the modern industry and to earn a very good salary, learning only JavaScript programming language is not sufficient, you must move on to learning JavaScript Frameworks also i.e., Angular. It doesn’t matter if you are thinking to start your career in software development or are already a software developer, you will always find Angular 2 Interview Questions useful. This is an open-source component-based UI framework that is written in TypeScript and is mainly used in building web, mobile, and desktop applications in HTML and JavaScript. Angular is an evolved and upgraded version of Angular JS and is invented by Google. For writing codes, Angular provides many language choices like Typescript, Dart, ES5, ES6. It supports both data and property blinding which allows a user to control DOM i.e., Data Object Model by binding class and HTML properties.
| Quick Facts About Angular 2 | |
|---|---|
| What is the latest version of Angular? | Angular 14 released on 2nd June 2022 |
| When did angular 6 release? | 14th September 2016 |
| Who is the developer of Angular 2? | |
| What language does Angular use? | TypeScript |
| License | MIT License |
| Official website | https://angular.io |
Frequently Asked Angular 2 Interview Questions for Developers
Promises in Angular 2 execute asynchronous functions in serial order by registering promise object. Additionally, promises are provided by build-in $q service. Promises have generated a new way into native JavaScript as a part of the ES6 specification
In Angular 2, a module groups the various components, pipes, directives, and services in a way that assists them in combining with other modules for creating an application.
A module can be used to hide or export pipes, directives, components and services.
rootScope
It's an AngularJS service that implements the underlying event and state management mechanism for AngularJS attributes, directives, views and controllers.
Scope
Whereas, it's a conventional parameter name given to a directive's link function's first argument.
An observable is an array where data arrives asynchronously.
Observables can help developers manage asynchronous data and are used within Angular, including event system and HTTP client service. Angular uses Reactive Extensions (RxJS), a third-party library, to use Observables.
In general, two-way data binding in Angular 2 is the automatic synchronization of data between the view components and model. Two-way data binding allows the users to treat the model as a single source of truth in your application.
This below mentioned will be the lifecycle hooks order in AngularJS.
- ngOnChanges()
- ngOnInit()
- ngDoCheck()
- ngAfterContentInit()
- ngAfterContentChecked()
- ngAfterViewInit()
- ngAfterViewChecked()
- ngOnDestroy()
- Avoid injecting dynamic Html content
- Sanitize external HTML
- Do not put external URLs in the application
- Use AOT compilation
- Prevent XSRF attack by restricting api
| Ng model | Ng bind |
|---|---|
| This works as a two-way data binding where the user has to bind a variable to the field and output the same variable wherever the user desire to display that updated value anywhere in the application. The syntax used for ng-model is – <textarea ng-model="propertyName"></textarea> |
It's a one-way data-binding used by developers for displaying the value inside HTML component as inner HTML. The syntax used for ng-bind is – <div ng-bind="propertyName"></div> |
Decorators allow developers to configure classes as elements by putting metadata on them.
The most common decorators are @Component one for components and @Injectable one for classes.
Decorators are new in TypeScript, and were not available in AngularJS. Angular2 onwards offers four types of decorators and each plays a unique role - Class, Property, Method, and Parameter.
- Angular Interviews are not just about learning Java Concepts but one of the toughest questions is to know about software and system designs.
- Practice is the key factor to crack any type of interview. Angular interviews are no exception too.
- You should know about basics such as TypeScript, Services, Metadata, Components, etc.
- If you know about the answer but you are taking too much time to explain it, then that land you nowhere. So yes, Time Yourself i.e. answer your question within a time limit.
- Teach a concept to your friend or anyone which you have learned. By this, you will know if you learn that concept.
- Honesty is the best policy. If you don’t know the answer just admit it without wasting the interviewer and your time.