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      Angular 8 Interview Questions and Answers

      Angular 8 Interview Questions and Answers
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      Angular 8 Interview Questions and Answers

      Introduction

      Angular is an open-source web application framework developed based on TypeScript and it is led by Google along with a large community. Angular is used in MEAN Stack along with MongoDB, Express.JS, and Node.JS for developing dynamic web applications faster and easier. Top companies are always looking for skilled and certified AngularJS professionals to work on their web and web app development. Here are the popular and frequently asked Angular 8 Interview Questions and Answers that help candidates clear the technical rounds successfully.

      Best of Angular 8 Interview Questions and Answers

      1. What are the specialized features in Angular 8?

      Angular 8 has the following specialized features for web developers

      • Dynamic imports for lazy routes
      • Differential loading for all applicable codes
      • Supports web workers, Bazel, and TypeScript 3.4
      • Opt-in usage sharing
      • NgUpgrade improvements

      2. What is Ivy in Angular 8?

      Ivy is the rendering engine for Angular 8 as an Opt-in for code adoption to the next-gen rendering pipeline and compilation. Following is the rendering pipeline in Angular 8

      Template HTML 🡪 Template Data🡪 Angular Interpreter 🡪 DOM

      3. Define Bazel in Angular 8

      Bazel is the build system in Angular 8 that provides a platform to make back-end and front-end services. It allows us to develop CLI (Command Line Interface) applications quickly and easily. The entirety of the Angular 8 framework is developed on Bazel and it enables us to divide applications into various units that are defined at the NgModule level. Bazel supports customization facilities to draw graphs and it can be used to identify information.

      4. What is the use of template-driven forms in Angular 8?

      Angular 8 template-driven forms are to include simple forms for applications where scalability is not a problem. They are very easy to use but not as scalable as Reactive Forms.

      5. What are the key parts of Angular 8 architecture?

      Following are the key parts of Angular 8 architecture

      • MetaData: MetaData is used to define a class for the configuration of the expected behavior of the class
      • Data Binding: It is used to bind the data from the component to the template
      • Components: Angular Components are the building blocks of all Angular applications
      • Modules: It is a group of related features and they are services under a single context
      • Services: Services are plain and simple TypeScript or JavaScript classes that provide specific functionalities and they help us perform a single task that can be reusable.
      • Templates: It is a superset of HTML that includes all the features of HTML along with additional features for binding the component data into the HTML for creating dynamic DOM elements.

      6. What is nglf directive?

      The use of the nglf directive is to provide the result for the following

      • When the expression is true, the element will be added
      • When the expression is false, the element will be removed

      7. What is data binding ?

      Data binding is the technique used to link the application’s data to the view layer. It makes the interaction between the DOM (Document Object Model) and the TypeScript code of our component. It will be in two types

      • One-way data-binding: It is used to bind the data from the component to the view or vice versa. One-way data-binding is a unidirectional data binding method that can either bind the data from the component to the view or bind the data from the view to the component.
      • Two-way data-binding: It helps the users to transfer data from the component to the view and from the view to the component. It is bi-directional communication.

      8. What is the use of Angular 8 components?

      Angular 8 components are classes with decorators for marking their own types. They offer metadata to help Angular perform a lot of things. Each application in Angular 8 will have one component defined as the root component that is used to connect page hierarchy with page DOM.

      9. Explain event binding

      Event binding is a technique used in Angular 8 to manage the events performed from the Document Object Model (DOM). For example, button clicks, mouse moves, mouse hovers, etc. The specified method in the component will be called immediately when the DOM event happens.

      10. Why launch AOT applications faster?

      Application components compiled with AOT (Ahead of Compilation) will be executed immediately without the need for the client-side compilation, templates are embedded as code within the components and there will be no need for a client-side request for template files, and the compiler will not entertain unused Angular directives. Hence, they are launched faster.

      11. What is the importance of Codelyzder in Angular 8?

      Codelyzer is a tool that is available for free with an open-source license used to check whether Angular TypeScript projects follow a set of rules. It checks errors in codes by not following pre-defined rules. It consists of more than 50 rules for validating. It runs on the tslint.json file to check the static code in Angular 8.

      12. Define Wildcard Route in Angular 8

      The wildcard route is used to set a route when the request URL doesn’t match any router paths. The set route matches every URL as an instruction to get a clear client-generated view after using the Wildcard Router. It always comes last as it requires to perform its task at the end. It is primarily used to define the route of the Angular 8 pages.

      13. Define String Interpolation in Angular 8

      String Interpolation is a one-way binding technique used in Angular 8 for extracting the output from a TypeScript code to the HTML template view layer. It displays the data from the component to the view layer with the curly braces. It is the techniques that add the value of property to the component.

      For Example 

      Syntax:
      {{ component_property }}

      Approach:

      Define a property in the app.component.ts file containing some string value.
      In the app.component.html file, bind the value of that property by calling the property name in double curly braces {{ property_name }}.

      Example 1:

      app.component.html

      HTML:
      <h1>
      {{ title }}
      </h1>

      app.component.ts

      Javascript:

      import { Component } from ‘@angular/core’;
      @Component({
      selector: ‘app-root’,
      templateUrl: ‘./app.component.html’,
      styleUrls: [‘./app.component.css’]
      })
      export class AppComponent {
      title = “SLA Institute”;
      }

      Output :

      output

      Example 2:

      app.component.html

      HTML:

      <h1 [style.color] = “‘gray'”
      [style.text-align] = “‘left'” >
      {{ title }} : {{ about }}
      </h1>

      app.component.ts

      Javascript:

      import { Component } from ‘@angular/core’;
      @Component({
      selector: ‘app-root’,
      templateUrl: ‘./app.component.html’,
      styleUrls: [‘./app.component.css’]
      })
      export class AppComponent {
      title = “Contact Number”;
      about = “+91 8870767784”;
      }

      Output :

      output1

      14. Define Promises in Angular 8

      The promises in Angular 8 can deal with a single asynchronous event at a time. They provide only a single value and they are not lazy. They can execute immediately after creation and are not cancellable. Promises don’t provide any operations and push errors to the child’s promises.

      15. What are observables in Angular 8?

      The observables can handle a sequence of the asynchronous event for a while and they are both synchronous and asynchronous. They can omit multiple values and they are lazy. They can’t be executed until subscribe to them using the subscribe() method. They can be canceled using the unsubscribe() method. They provide the map for operators like forEach, reduce, retry, filter, and retryWhen. They deliver errors to subscribers.

      Conclusion

      We hope the given Angular 8 Interview Questions and Answers prepared by our professionals help candidates ace the interviews of top companies. Learn the best Angular Training in Chennai at SLA to gain expertise with satisfying hands-on exposure for performing the projects well.

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