Here are the Top 12 Angular advanced interview questions. Let’s get started!<\/p>\n\n
It is important to prepare well for an Angular developer interview. In later rounds the interviewer may ask Angular advanced interview questions preparing well will help d<\/span>emonstrate in-depth knowledge and experience with these advanced concepts can set a candidate apart from other Angular developers.<\/span><\/p>\n Also read: <\/strong>38 Smart Questions to Ask in a Job Interview<\/a><\/p>\n View encapsulation in Angular can affect the component template and style of the entire program or vice versa. Three encapsulations techniques available are \u2013<\/span><\/p>\n RxJS is an acronym meaning Reactive extensions for JavaScript. It is used to enable the use of observables in our JavaScript project, allowing us to do reactive programming. RxJS is utilized in many popular frameworks, including Angular since it allows us to compose our asynchronous or callback-based code into a sequence of operations executed on a data stream that releases values from a publisher to a subscriber. Other programming languages, such as Java and Python, offer packages that allow them to develop reactive programs utilizing observables.<\/span><\/p>\n Most of the time, rxJs is used in HTTP calls with angular. Because http streams are asynchronous data, we can subscribe to them and apply filters to them. This is one of the advanced interview questions asked several times in an interview.<\/span><\/p>\n Example:\u00a0<\/b>The following is a simple example of how RxJs can be utilized with HTTP calls.<\/span><\/p>\n let\u00a0 stream1 = httpc.get(“https:\/\/www.example.com\/somedata”);<\/span><\/p>\n \u00a0let stream2 = stream1.pipe(filter(x=>x>3));<\/span><\/p>\n \u00a0stream2.subscribe(res=>this.Success(res),res=>this.Error(res))<\/span><\/p>\n Also read:\u00a0Top 20 Angular version interview questions<\/a><\/strong><\/p>\n Dependency injection is an application design pattern implemented in Angular. It forms one of the core concepts in Angular.\u00a0<\/span><\/p>\n Dependency are services with functionality. Different components and directives can need functionality of a service. Angular framework provides a mechanism to add these dependencies to our components and directives. We are just making dependencies which are injectable across all components of an application.\u00a0<\/span>This is how Dependency Injectors (DI) works. Take the example of ng g service test<\/span><\/p>\n import { Injectable } from ‘@angular\/core’;<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0@Injectable({<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0providedIn: ‘root’<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0})<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0export class TestService {<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0importantValue:number = 42;<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0constructor() { }<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0returnImportantValue(){<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0return this.importantValue;<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0\u00a0\u00a0\u00a0<\/span><\/p>\n \u00a0As one can notice, we can create injectable dependencies by adding the\u00a0<\/span>@Injectable<\/b>\u00a0decorator to a class.<\/span><\/p>\n We inject the above dependency inside the following component: \u00a0\u00a0<\/span><\/p>\n \u00a0import { TestService } from ‘.\/..\/test.service’;<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0import { Component, OnInit } from ‘@angular\/core’;<\/span><\/p>\n <\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0@Component({<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0selector: ‘app-test’,<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0templateUrl: ‘.\/test.component.html’,<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0styleUrls: [‘.\/test.component.css’]<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0})<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0export class TestComponent implements OnInit {<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0value:number;<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0constructor(private testService:TestService) { }<\/span><\/p>\n <\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ngOnInit() {<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0this.value = this.testService.returnImportantValue();<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/span><\/p>\n One can see we have imported our TestService at the top of the page. Then, we created an instance inside the constructor of the component and implemented the\u00a0<\/span>returnImportantValue<\/b>\u00a0function of the service.<\/span><\/p>\n From the above example, we can observe how angular provides a smooth way to inject dependencies in any component.<\/span><\/p>\n AOT or Ahead Of Time compilation converts your code during the build time before the browser downloads the code. This ensures the browsers are render faster. To start AOT compilation, include the -aot option with the ng build and ng serve command.\u00a0<\/span><\/p>\n JIT or Just-in-command compilation process is a way of compiling computer code to machine code during execution or run time. JIT is also known as dynamic compilation. JIT compilation is the default when you run the ng build and ng serve CLI command.\u00a0<\/span><\/p>\n Also read:\u00a0Top 15 Angular basic interview questions<\/a><\/strong><\/p>\n Dependency injection, or DI, is one of the fundamental concepts in Angular. DI is wired into the Angular framework and allows classes with Angular decorators, such as Components, Directives, Pipes, and Injectables, to configure dependencies that they need.<\/span><\/p>\n Two main roles exist in the DI system: dependency consumer and dependency provider.<\/span><\/p>\n How are component dependencies injected in a workflow?<\/strong><\/p>\n The first step is to <\/span>add the @Injectable decorator to show that the class can be injected.<\/span><\/p>\n @<\/span>Injectable<\/span><\/a>()<\/span><\/p>\n class HeroService {}<\/span><\/p>\n The next step is to make it available in the DI by providing it. A dependency can be provided in multiple places:<\/span><\/p>\n <\/p>\n @<\/span>Injectable<\/span><\/a>({<\/span><\/p>\n \u00a0\u00a0providedIn: ‘root’<\/span><\/p>\n })<\/span><\/p>\n class HeroService {}<\/span><\/p>\n When you provide the service at the root level, Angular creates a single, shared instance of the\u00a0HeroService\u00a0and injects it into any class that asks for it. Registering the provider in the\u00a0@<\/span>Injectable<\/span><\/a>\u00a0metadata also allows Angular to optimize an app by removing the service from the compiled application if it isn’t used, a process known as tree-shaking.<\/span><\/p>\n Promises and Observable both deal with Asynchronous events in Angular. Promises handles one event at a time and observables handle a sequence of events over time.\u00a0<\/span><\/p>\n Promises give one value at a time. They execute immediately after creation and are not cancellable. They are Push errors to child promises.\u00a0<\/span><\/p>\n Observables are executed only when subscribed to them using the Subscribe () method. They give multiple values over a period of time. They are used for functions like forEach, filter, and retry. Observable deliver errors to the subscribers. If you use the unsubscribe method() the listener stops receiving further values.\u00a0<\/span><\/p>\n Also read:\u00a08 Secrets of a Winning Interview Dress Code<\/a><\/strong><\/p>\n ngOnInit is a lifecycle hook and a callback method that is run by Angular to indicate that a component has been created. It takes no parameters and returns a void type.<\/span><\/p>\n export class MyComponent implements OnInit {<\/span><\/p>\n \u00a0\u00a0constructor() { }<\/span><\/p>\n \u00a0\u00a0ngOnInit(): void {<\/span><\/p>\n \u00a0\u00a0\u00a0\u00a0\/\/….<\/span><\/p>\n \u00a0\u00a0}<\/span><\/p>\n }<\/span><\/p>\n What is bootstrap? How is it embedded in Angular?<\/strong><\/p>\n Bootstrap is a strong toolkit. It is a collection of HTML, CSS, and JavaScript tools, developers use to build responsive web pages and applications. There are two ways to embed bootstrap library into your application.\u00a0<\/span><\/p>\n In Angular .subscribe() is a method of observable type. The observable type is a utility that have synchronous and asynchronous stream data to a variety of components or services that have subscribed to the observable. The subscribe method takes 3 methods as parameters-<\/span><\/p>\n For using cookies in Angular, you need to include a module called ngCookies angular-cookies.js.<\/span><\/p>\n To set Cookies<\/b>\u00a0\u2013 For setting the cookies in a key-value format \u2018put\u2019 method is used.<\/span><\/p>\n cookie.set(‘nameOfCookie’,”cookieValue”);<\/span><\/p>\n To get Cookies \u2013<\/b>\u00a0For retrieving the cookies \u2018get\u2019 method is used.<\/span><\/p>\n cookie.get(\u2018nameOfCookie\u2019);<\/span><\/p>\nWhat is Easy and Lazy loading?<\/strong><\/span><\/h2>\n
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What is the view encapsulation in Angular?<\/strong><\/h2>\n
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What is RxJs in Angular?<\/strong><\/h2>\n
Explain string interpolation and property binding in Angular.<\/strong><\/h2>\n
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Explain the concept of Dependency injection.<\/strong><\/span><\/h2>\n
What is the difference between AOT and JIT?<\/strong><\/h2>\n
What is dependency injection?<\/strong><\/h2>\n
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What are promises and Observables in Angular?<\/strong><\/h2>\n
What are ngOnInit()? How are they defined?<\/strong><\/h2>\n
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11.What is subscribing?<\/strong><\/h2>\n
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In Angular, describe how to set, get, and clear cookies()?<\/strong><\/h2>\n