Top 50 Angular Interview Questions And Answers

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Angular interview questions and answers

Angular Interview Questions and Answer

Do you ever dream about becoming and working as an angular Developer? Or switching from your current job post to the post of Angular developer? If you are going to perform any of these tasks, then for your easy way, this blog is very useful and helpful. We have framed the top 50 questions and answers that your interviewer can ask in the path of getting the job of Angular developer. 

These questions and answers will be the most beneficial and can give you what you have desired for so long in your career. The questions and answer are stated as 

1 – How do you define Angular?

An Angular is a form of Typescript based upon the open-source web application framework. It is maintained and formally developed by Google. You can easily build front-end web-based applications powerfully with it. Various features of Angular are 

● Declarative templates

● Dependency injections

● End to end tooling

etc…

2 – Angular has been introduced to the world as a client-side framework. Explain its reason

Before angular, developers use Vanilla JS and jQuery for building websites. But when building websites becomes a complex task to add new features and functions, developers find it challenging to work with Vanilla JS and jQuery. That is why angular has been introduced to support the developers to address these complications easily and divide the code into a smaller bit of information. The client-side framework can’t be to develop advanced web applications. 

3 – What is an ng content directive?

With ng content directive, you can build reusable components for content projections. It can also be used to make the content look like an HTML tag. 

4 – State some features of angular

Various feature of angular JS is

● Accessibility applications

● Angular CLI

● Animation support

● Cross-platform app development

● Code generation

● Code splitting

● Code editors and IDE

● Templates

● Testing

and many more… 

5 – How angular framework is more effective than other frameworks?

To understand this, you can read the advantages offered by Angular 

● Out of box features

● Declarative UI

● Long term google support

and more…


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6 – Point out the difference between Angular and angular JS

Parameters Angular JS Angular
Architecture The model view controller architecture of angular JS facilitates the framework to be perfect for use in business logic, controlling process, and information.  It replaces angular with components which are directives with a predefined template.
Language It uses typed language i.e JavaScript. It uses both TypeScript and JavaScript language for better performance of developing large applications. 
Mobile support No mobile support.  Support with mobile browsers.

7 – State some lifecycle hooks in angular

Some angular lifecycle hooks are stated as 

● ngOnChanges()

● ngOnInit()

● ngDoCheck()

● ngAfterContentLnit()

● ngAfterContentChecked()

● ngAfterViewInit()

● ngAfterViewChecked()

● ngOnDestroy()

8 – Is it possible to make an angular application for rendering on the server-side?

Of course, yes, because angular offers a technology that is angular universal for rendering applications on the server-side. 

9 – What are dependency injections?

It is the angular application designing pattern which forms the concepts of angular. With angular, you can smoothly inject the dependencies of functions and applications into components and directives. 

10 – What is MVVM architecture?

It can remove the coupling of components. It has three parts 

● Model

● View

● ModelView

11 – Define ahead of time compilation and state its advantages

This angular application has various components and templates which a browser cannot understand. That’s why every angular application needs to be complied with before launching it to the browser. It takes JS codes and compiles them to produce some JS codes. Its advantages are

● Fast rendering

● Fewer ajax requests

● Minimizing errors

● Better security

12 – What are the benefits and drawbacks of using Angular

Following are some benefits

● Can add custom directive.

● Extraordinary community support.

● Stimulates clients and server transmission.

● Follows the architecture MVC pattern.

Some drawbacks are

● Complex files can be inconvenient to use. 

● Changing applications sometimes do not perform well. 

● For learning angular, you need to have effort and time. 

13 – Define string interpolation of angular 

It is the special syntax that uses template expressions to display component data. The template expressions are covered in the curly braces{}. It is also known as the moustache syntax. 

14 – What is angular authentication and authorization?

JSON web token (JWT) has the information for the current user through which a user can identify the given JWT. It is called authentication. On the other hand, authorization is when a user can access a minimal number of things. 

15 – Explain the scope hierarchy in Angular

A scoped object in the hierarchy has been organized by Angular, which is used by views. It’s called the scope hierarchy in Angular. Each view will have its scope in the scope hierarchy. 

16 – What is the method of generating a class in angular 7 with CLI?

A class created with a name dummy will be formed as the 

ng generate class dummy [options]

17 – Difference between Angular and backbone JS

Parameters Angular Backbone JS
Architecture It uses MVC architectural structure and makes two-way binding for driving applications.  It does not offer any data binding process and uses an MVP architectural structure.
Community support It is supported by Google. It only documents on backbone JS and does not have any template. 
Data binding Two-way data binding and complex structure.  Don’t have any data binding and has a simplistic API. 

18 – Explain the template concept in angular

Templates have been written by HTML and have angular-specific attributes and elements. It is combined with information from the controller and model. It can be rendered to cater to the user with changing views. 

19 – Explain directives in angular 

It is the most angular feature, which allows the angular developer to write new application-specific HTML syntax. They are functions that are executed by angular. It is of mainly 3 types.

● Attribute directive

● Component directive

● Structural directive

20 – State the building blocks of angular

The building blocks of angular are 

● Components

● Data binding

● Dependency injections

● Directives

● Metadata

● Modules

● Routing

● Services

● Template

21 – Point the differences of angular vs jQuery

Parameters Angular jQuery
Data binding It has two-way data binding It doesn’t have any
Support with RESTful API It supports these functions  It doesn’t
Deep linking routing It provides deep linking routing It doesn’t 

22 – Define angular material

It helps in making attractive, consistent, and available web pages and applications. It follows modern design principles, which include browser portability and graceful degradation. It is angular’s UI component library. 


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23 – Explain data binding and state its ways to be done

Data binding is used to connect application data with the data object model. A data binding can happen between HTML and components. 

● Event binding

● Property binding

● Two-way binding

24 – Define digest cycle in angular

To track the changes in the watch variable’s value, the process used is the digest cycle. It gets triggered implicitly, and it can be started with the $apply() function. 

25 – State the filters of angular JS

To format the value of expression so that it can be present in the user, AngularJS uses filters. You can easily add these filters to controllers, directives, services, and templates. You can also customize some filters. It can be added to expression with | character. Many types of filters in angular JS are

● Currency

● Date

● Filter

● JSON

● limit

● Lowercase

● Number

● orderBy

26 – What are the features of angular 6?

Various features of angular 6 areas

● Angular elements

● Tree shakeable provider

● RxJS 6

● i18n (internationalisation)

27 – How to define ngOnInit()

It’s a lifecycle hook of angular, called when angular has finished initializing all data-bound properties. 

E.g. Interface OnInit. {

ngOnInit() : void

       }

28 – How to create a code for decorator 

function Dummy (target) {

dummy.log( “This decorator is Dummy”, target);

  }

29 – Through which process a TypeScript code is converted to JavaScript code?

The process is called transpiling. Then also, a typescript will be used in angular for writing code. And it gets automatically transpile to Javascript. 

30 – Define view encapsulation and its ways of doing it in angular

It determines the styles defined in the particular component, which will affect the entire application or not. Angular supports three ways of ViewEncapsulation

● Emulated

● Native

● None

31 – State the purpose of angular 

The primary purpose of using angular is to make fast, dynamic, and scalable web applications for ease, using components and directives. 

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32 – Point the difference between component and directive

Parameters Component Directive
Registration Annotation is used for registering components.  The directive uses its component to register. 
Purpose Its purpose is to break complex components into smaller ones. To create new components is the purpose of the directive. 
Views It requires a decorator, template, and URL to specify view.  It has nothing to do with it. 

33 – State the primary language used in Angular

Angular has mainly the basis of typescript and HTML. HTML is used for the template, whereas Typescript is used for components. 

34 – Give difference of one way and two-way binding

 

One way binding Two-way binding   
The view in one way does not change or update itself wherever there is model change. This view is updated continuously as the data model changes.   

35 – Show examples of using ngIf and ngFor

ngIf

Show this only if the boolean “display” is true

ngFor

{ {student.name} }

{ {i} }

36 – Give a simple code to show a pipe

Price is {{price | currency }}

37 – Create a parameter used pipe in above demonstration. 

Price is {{ price | currency :” USD$” : 0.00 }}

38 – How to chain pipes

We can easily chain the pipes by applying the angular filter. The example is given below

Average is. {{ average | uppercase | number}}

39 – How to create a custom pipe?

To create a custom pipe, follow the steps below

● Import pipe decorator from the angular library. 

● A pipe is a class that can be decorated with the above metadata. 

● The pipe should be implemented to method transform() of pipe transform class. 

● Give the name to pipe in the code. 

40 – State the purpose of async pipe

It subscribes to an observable and returns to its value. If the new value is radiated, the pipe marks need to be checked for any components. 

41 – State the events of router navigation

Router navigation will help you track the lifestyle of a route. These are stated under

● navigation Start

● RouteConfigLoadStart

● RouteConfigLoadEnd

● RoutesRecognised

● GuardsCheckStart

● ChildActivationStart

● ActivationStart

● GuardsCheckEnd

● ResolveStart

● resolved

● ActivationEnd

● ChildActivationEnd

● NavigationEnd

● NavigationCancel

● NavigationError

● Scroll

42 – Explain the wildcard route

It is a route that consists of (**) to match any URL. A wildcard route is proven to be very useful in matching URLs when their predefined routes don’t match. And rather to throw an error, we use a wildcard route for defining a component for the same. 

43 – How to do animation in angular?

For using the module animation, you need to enable it. You can import BrowserAnimationModule to import. Eg 

import { BrowserAnimationModule } from ‘@angular/platform – browser/animations’; After this, import the required animation functions into the component files. 

import { state, animate, transition, //…. } from ‘@angular/animations’;

44 – Define unique transition states.

These are the wildcard and void. Wildcard can be matched with any animation state. With void, you can configure transition for elements entering and leaving the pages. 

45 – State the function through which you can control complex animation sequences

●    Query() – It finds one or more HTML elements in the existing element for animation in the sequence.

●    Stagger() – It can be applied in cascading delay after animations. 

●    Group() – Through this, you can run various animations in parallel order. 

●    Sequence() – It runs animations one after another. 

46 – Explain the process of representing the metadata in angular?

Metadata in angular can be represented with decorators like class decorators, property decorators, methods decorators, and more. You can get it cleared by this example 

@component, @NgModule, etc…

47 – Define class decorators in angular

It contains the metadata of the suitable class type. A class decorator appears before the class definition and declares the class of a particular type. Various class decorators are given as @component, @NgModule, @Pipe, @Directive, @injectable, etc… 

48 – Define package.json and state its purpose

You can easily manage project dependencies with the JSON package. You can mention details like version, language, and more in a JSON package. For example, if we are using typescript, we can write typescript and its version name in the package like metadata.json, tsconfig.json, etc. 

49 – What does {} represents, explain its use by showing an example

It usually represents interpolation. It’s a syntax for which angular used it to property binding. Component amme will be written in the {}. Which is during execution can be replaced with a string name. It’s an example as {{apptitle}}

50 – What does this [()] mean?

It’s a ngModel that is used for data binding. You can write it as [(ngModel)]=”property value”. 

Conclusion

If you prepare these angular questions and answers well for your job interview, you can easily clear it and get the angular developer’s post. While if you have prepared everything, but forget something in the interview, don’t hogwash or don’t say anything wrong. Just try to revise it and whatever you need about that question because the candidates who give all answers without getting nervous will surely get the angular developer’s post. These interview questions and answers will help you achieve what you have desired for so long. 

So, all the best for your interview. Face it with confidence.