Angular 2 Interview Questions and Answers

1. Best Interview Question Angular 2 Interview Questions Angular 2 Interview Questions and Answers Angular 2 is the upgraded and evolved version of AngularJS, a JavaScript framework that was developed by Google. Angular 2 is used for building single-page web or mobile applications. Written in TypeScript, Angular implements core functionalities as TypeScript libraries that get imported into apps. AngularJS is known for intuitive HTML and amazing new features where developers are free to use ngIf and ngRepeat, modular design and various other built-in functionalities. Our recently updated Angular 2 developer interview questions can help you crack your next interview. One of the unique features of the Angular 2 framework is that it is designed in such a way that each component is independently testable, using different methods. Angular 2 is mostly a rewrite of the first version to avoid its faults. One of the most significant advantages of Angular 2 is that it offers more language choices such as TypeScript, ES6, Dart and ES5 for writing codes. We have an impressive collection of Angular 2 Interview Questions that is a must read for all developers and designers! Development History Google originally developed AngularJS in 2009, and its first version was released in 2012. Since then AngularJS has been the leading open-source JavaScript framework until later versions were launched. This is the most frequently asked Angular 2 Interview Questions. Latest Version: Angular 2 was released in September 2016. Google released AngularJS 1.7.5 in October 2018. Advantages of Angular 2 Programming Language Angular 2 has the following advantages over its predecessor: Code is simpler Faster rendering Built with mobile devices in mind Better performance Easier to read and learn Simplified architecture because it is component-based Angular 2 Interview Questions and answers Looking for a new job? Do not miss to read our Angular 2 Interview Questions and answers. Whether you are a fresher or an experienced, these questions and answers that can help you to crack your interview. 01. What is Angular 2 and also explain its components?  02. List the new features of angular 2? Explain  03. Explain directives in Angular 2? Explain  04. Explain routing in angular 2?  05. Explain pipes in Angular 2?  06. How to redirect to 404 or other path if the path does not exist in Angular 2?  07. What is the use of codelyzer in angular 2? Explain  08. Explain lazy loading and How to enable it in angular 2?  09. What is the use of Typescript in Angular2?  10. What is the difference between angular 2 and angular 1? Explain  11. What do you mean by module in angular 2?  12. How we can handle errors in Angular 2?  13. What are observables in angular 2? Explain  14. Explain event emitters in Angular 2 and how it works?  15. Explain the difference between component and directive in angular 2?  16. Explain the security threats should we be aware of in angular 2?  17. What do you mean by decorator in angular 2?  18. How to declare a global variable in Angular 2?  19. How to pass data into components with @Input in Angular 2? 

2. 20. What is services and also explain its features in angular 2?  21. Explain the difference between observables and promises in angular 2?  22. Explain the steps for creating a services in Angular 2?  23. How to create custom Pipes in Angular 2?  24. How we can use styleUrls and styles in Angular 2?  25. What are cookies and how we can get and set Cookies in angular 2?  26. What are the difference between @injectable() vs. @inject() in angular 2?  27. What is @ngmodule in Angular 2? Explain  28. What is AOT compilation why use in angular 2?  29. What are the advantages & limitation of AOT compilation?  Angular 2 Interview Questions #1  What is Angular 2 and also explain its components? Angular 2 is the upgraded and evolved version of AngularJS, a JavaScript framework that was developed by Google. Angular 2 is used for building single-page web or mobile applications. Components are eseential elements of Angular 2 apps, and an application can have a number of components. In Angular 2, components perform all the tasks that were done by scopes, controllers and directives, such as creating or adding Data, logic and custom elements. In Angular 2 an component consists of the following: Template Class Metadata The three steps to creating a component asre as follows: Create class and export it. Decorate class with @component metadata. Libraries and modules can be imported.  suggest an answer Angular 2 Interview Questions #2  List the new features of angular 2? Explain These features stand out: Use of TypeScript Built-in support for mobile app development Improved performance Support for 3 directives types - component, decorator, and template. Enhanced Dependency Injection Increased data binding Supports component-based architecture Cross-platform and cross-browser support  suggest an answer Angular 2 Interview Questions #3  Explain directives in Angular 2? Explain Directives are the extended HTML attributes and they are also the most important features of Angular applications. They introduce syntax or markup. There are 3 kinds of directives - Components, Structural and Attribute. This information is likely to be asked in angular 2 interview questions

3.  suggest an answer Angular 2 Interview Questions #4  Explain routing in angular 2? The Router enables viewers to navigate from one view or page to the next as they perform application tasks. Routing assists users based on the option they select on the main web page. Based on user options, the Angular Component renders to the user.  suggest an answer Angular 2 Interview Questions #5  Explain pipes in Angular 2? In all Angular version from 2 onwards, there is a common feature called Pipes. This feature helps developers create custom pipes. Pipes are used to write display-value transformations that developers can declare in their HTML. A pipe inputs data and transforms it in the required output.  suggest an answer More interview Questions from Frontend /UI OOPS INTERVIEW QUESTIONS LARAVEL INTERVIEW QUESTIONS WORDPRESS INTERVIEW QUESTIONS YII INTERVIEW QUESTIONS DRUPAL INTERVIEW QUESTIONS JOOMLA INTERVIEW QUESTIONS CAKEPHP INTERVIEW QUESTIONS CODEIGNITER INTERVIEW QUESTIONS YII 2 INTERVIEW QUESTIONS LARAVEL 5 INTERVIEW QUESTIONS ZEND FRAMEWORK INTERVIEW QUESTIONS ZEND 2 FRAMEWORK INTERVIEW QUESTIONS SYMFONY INTERVIEW QUESTIONS MAGENTO INTERVIEW QUESTIONS OPENCART INTERVIEW QUESTIONS Angular 2 Interview Questions #6  How to redirect to 404 or other path if the path does not exist in Angular 2? Using angular routing you can navigate from one view or page to another while performing your tasks. You can configure a URL to redirect to the next URL. This feature can be handled to address the "404 Not Found" problem. Using location services in Angular routing you can go back and forward through the history of pages. Syntax : We can use {path: '/OUR_PATH', redirectTo: ['redirectPathName']} Example {path: '/404', name: 'PageNotFound', component: NotFoundComponent}  suggest an answer

4. Angular 2 Interview Questions #7  What is the use of codelyzer in angular 2? Explain It is an open source tool for running and checking if the pre-defined coding guidelines were followed or not. It does static code analysis for typescript and angular projects. It runs on top of tslint and coding conventions are defined in tslint.json file. Editors such as Visual Studio Code support codelyzer by doing basic settings.  suggest an answer Angular 2 Interview Questions #8  Explain lazy loading and How to enable it in angular 2? Lazy loading allows developers to load different code pieces on demand. For instance, if you have a retail application that has different departments like garments, groceries, electronics, etc. If you load all the sections in the beginning, your application will be slow. This is when you need lazy loading. It helps application load faster because it loads only parts that the user wants to see. You can implement lazy loading in 4 steps: Update route file. Get angular-router-loader and add it to your config file Define lazy routes Import routes to the module.  suggest an answer Angular 2 Interview Questions #9  What is the use of Typescript in Angular2? The biggest benefit of TypeScript is tools like advanced autocompletion, refactoring and navigation. Because of TypeScript developers do not need to rewrite to migrate to JavaScript. They can do it one module at a time. In addition, because of TypeScript, the code is easier to understand.  suggest an answer Angular 2 Interview Questions #10  What is the difference between angular 2 and angular 1? Explain Angular 1 Angular 2 1. No mobile support Mobile-oriented 2. Only supports Dart, ES6 and ES5 Offer more language choices 3. Easy to set up Dependent on libraries. Requires efforts to set up. 4. Based on controllers and scope Component-based.  suggest an answer Angular 2 Interview Questions #11  What do you mean by module in angular 2?

5. 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.  suggest an answer Angular 2 Interview Questions #12  How we can handle errors in Angular 2? All Angular 2 apps have the option of finding and handling errors. This can be done by including the ReactJS catch library and using the catch function. Example We have add this code in the product.service.ts file import { Injectable } from '@angular/core'; import { Http , Response } from '@angular/http'; import { Observable } from 'rxjs/Observable'; import 'rxjs/add/operator/map'; import 'rxjs/add/operator/do'; import 'rxjs/add/operator/catch'; import { IProduct } from './product'; @Injectable() export class ProdService { private _producturl = 'app/products.json'; constructor(private _http: Http){} getproducts(): Observable { return this._http.get(this._producturl) .map((response: Response) => response.json()) .do(data => console.log(JSON.stringify(data))) .catch(this.handleError); } private handleError(error: Response) { console.error(error); return Observable.throw(error.json().error()); } }  suggest an answer Angular 2 Interview Questions #13  What are observables in angular 2? Explain

6. 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.  suggest an answer Angular 2 Interview Questions #14  Explain event emitters in Angular 2 and how it works? Any change that occurs in the component gets propagated from the existing component to its children. If this change needs to be reflected its parent component, you can use using Event Emitter api to emit the event. EventEmitter is class in @angular/core module that is used by directives and components to emit events. @output() somethingChanged = new EventEmitter(); You can use somethingChanged.emit(value) to emit any event. You can do this in setter when the value is changed in the class.  suggest an answer Angular 2 Interview Questions #15  Explain the difference between component and directive in angular 2? Components Directive 1. To register, use @Component meta-data To register, use @Directive meta-data annotation annotation 2. Used to create UI widgets and break up app into Use to design re-usable components and add behavior to smaller components existing DOM element. 3. Only one component allowed per DOM element Many directives allowed per DOM element. 4. @View decorator is mandatory Does not use View.  suggest an answer Angular 2 Interview Questions #16  Explain the security threats should we be aware of in angular 2? 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  suggest an answer Angular 2 Interview Questions #17  What do you mean by decorator in angular 2? 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.

7.  suggest an answer Angular 2 Interview Questions #18  How to declare a global variable in Angular 2? The simplest way is to put the variables in a file and export them. In order to use global variables, you can use an import statement. // // ===== This File is as globalfile.ts // 'use strict'; export const name='bestinterviewquestion.com'; After that we can export this file where we want to use these global variables value. import * as myGlobalsFile from './globalfile';  suggest an answer Angular 2 Interview Questions #19  How to pass data into components with @Input in Angular 2? You can do this through property binding feature in Angular2. In order to bind data to components, you need to create a custom property bind. This can create it via “input” binding for passing data from one component to another. You can create the custom input binding via the @Input() decorator!  suggest an answer Angular 2 Interview Questions #20  What is services and also explain its features in angular 2? Services allow greater separation of concerns in Angular applications. They also provide modularity by allowing developers to extract common functionalities out of components. Adding Services to Angular applications makes components free from data access code. Service has the following features: Singleton, i.e. only one instance of service will exist throughout the application. Capable of returning data in the form of Observables and promises. Decorated with @Injectable() decorator  suggest an answer Angular 2 Interview Questions #21  Explain the difference between observables and promises in angular 2? Promise Observable 1. Have one pipeline Pass data in multiple pipelines 2. Only used with async data return Could be subscribed later on 3. Not easy to cancel Cancellable  suggest an answer

8. Angular 2 Interview Questions #22  Explain the steps for creating a services in Angular 2? Here are the steps: Import injectable member Add @Injectable Decorator Export Service class Here is the syntax: import { Injectable } from '@angular/core'; @Injectable() export class MyCustomService { }  suggest an answer Angular 2 Interview Questions #23  How to create custom Pipes in Angular 2? In Angular 2, you can create custom pipes. The simplest way is as follows. import { Pipe, PipeTransform } from '@angular/core'; @Pipe({name: 'Pipename'}) export class Pipeclass implements PipeTransform { transform(parameters): returntype { } } In the above code, // Pipename' is pipe's name. // Pipeclass is class that is assigned to custom pipe. // Transform is the function that works with custom pipe. // Parameters are the parameters that get passed to the pipe. // Returntype is the return type of the custom pipe.  suggest an answer Angular 2 Interview Questions #24  How we can use styleUrls and styles in Angular 2? This information is trending in angularjs 2 interview questions for experienced professionals. In Angular 2, styles or styleUrls affect the style of template elements. The built-in properties in the component Decorator allow developers to encapsulate styles directly as part of their components. Both style and styleUrls are arrays, which means that for styles, you can apply many definitions for each position. For styleUrls, you can split up different style rules into different style sheets.  suggest an answer Angular 2 Interview Questions #25  What are cookies and how we can get and set Cookies in angular 2? Cookies are packages of information that are stored by the browser from websites that use cookies for multiple uses. There are two ways to create cookies: Inject service in components providers. Get it via npm. In order to set cookies, you can use the following method:

9. // the put method takes in the name of the cookie and the value for that cookie. // if we wanted to define cookie options then we would pass in a third parameter to // this method containing those options. this._cookieService.put('test', 'test');  suggest an answer Angular 2 Interview Questions #26  What are the difference between @injectable() vs. @inject() in angular 2? @Injectable @Inject 1. Aims to set metadata of dependencies to be injected into Tells Angular what parameter must be constructor injected 2. Without it, no dependency can be injected Only needed to inject primitives  suggest an answer Angular 2 Interview Questions #27  What is @ngmodule in Angular 2? Explain It configures the injector and compiler, and assists in organizing things together. This class is marked by the @NgModule decorator. It can identify module's directives, components, and pipes, making them public as required through the exports properties so that they can be used by the external components.  suggest an answer Angular 2 Interview Questions #28  What is AOT compilation why use in angular 2? The Angular Ahead-of-Time (AOT) compiler converts Angular HTML and TypeScript codes into JavaScript code during the build phase before the browser can download and run the code. Here are benefits of compiling with AOT: Fast rendering Lesser asynchronous requests Smaller download size of Angular framework Detects errors easily Improved security  suggest an answer Angular 2 Interview Questions #29  What are the advantages & limitation of AOT compilation? Advantages- Fast download Quicker rendering Reduces Http Requests Catches errors during the build phase Disadvantages- Only works with HTML and CSS; Not other file types.

10. Must maintain bootstrap file AOT version Must clean-up before compiling.  suggest an answer Most Searched Questions LARAVEL INTERVIEW QUESTIONS 61 WORDPRESS INTERVIEW QUESTIONS 50 YII INTERVIEW QUESTIONS 27 REACT JS INTERVIEW QUESTIONS 31 JQUERY INTERVIEW QUESTIONS 50 ANGULARJS INTERVIEW QUESTIONS 30 HTML INTERVIEW QUESTIONS 33 HTML5 INTERVIEW QUESTIONS 24 CSS INTERVIEW QUESTIONS 35 NODE JS INTERVIEW QUESTIONS 56 C INTERVIEW QUESTIONS 43 C++ INTERVIEW QUESTIONS 28 JAVA INTERVIEW QUESTIONS 49 ASP.NET INTERVIEW QUESTIONS 18 GO PROGRAMMING INTERVIEW QUESTIONS 34 PYTHON INTERVIEW QUESTIONS 30 SQL INTERVIEW QUESTIONS 25 MYSQL INTERVIEW QUESTIONS 38 MONGODB INTERVIEW QUESTIONS

11. 24 PHP INTERVIEW QUESTIONS 76 Latest Blogs Features of laravel 5.7 over other versions 2 months ago

12. 5 Reasons PHP is the Most Preferred Language 2 months ago Frameworks vs. CMS – Which One is Better and Why? 2 months ago

13. Why Bootstrap is the Best UI Design Tool 2 months ago Featured Category Web Testing / Development Frontend /UI Database Design Mobile App Government HR QA Networking Digital Marketing PHP SEO SEM SMM/SMO java Best Interview Questions PHP Interview Questions Laravel Interview Questions Wordpress Interview Questions symfony Interview Questions Drupal Interview Questions YII Interview Questions Opencart Interview Questions CakePHP Interview Questions OOPS Interview Questions Popular Interview Questions Node JS Interview Questions GO Interview Questions Python Interview Questions

14. HTML Interview Questions CSS Interview Questions React JS Interview Questions Angular JS Interview Questions Mysql Interview Questions Common Interview Questions Our Categories Website development HR Interview Questions SEO Interview Questions Database Interview Questions Frontend / UI Interview Question Testing / QA Interview Questions Mobile App Interview Questions Designing Interview Questions Govt. jobs Interview Questions Newsletter Stay update with our latest interview questions Your Email Address  Home About Us Blog Contact Privacy Policy Copyright © 2018 All rights reserved | Application is made by Sharptechsolution 