Angular Interview Questions

Introduction Angular interview questions

Are you preparing for an Angular interview and want to know what Angular interview questions they will ask? If so, it’s important to understand the framework and the various concepts associated with it. In this article, we’ll provide an introduction to the most commonly asked Angular interview questions. We’ll discuss the Angular framework, application development processes, components and modules, TypeScript, data binding, services and dependency injection, directives and pipes, authentication, and authorization.

In order to prepare well for an Angular interview and to learn Angular interview questions, you should be familiar with essential concepts related to the framework and all its components and modules. Components are reusable pieces of code that define views in your application. Modules are containers with related code that can be loaded independently from other module code in your application.

Let’s help you understand how to prepare for Angular interview questions. It is also important to have an understanding of TypeScript, which is a typed superset of JavaScript that compiles down to plain JavaScript code for execution in browsers or on any platform that supports JavaScript. Knowledge of data binding methods such as interpolation or property binding is also essential when preparing or learning for Angular interview questions, while understanding how services work along with dependency injection can also help you answer Angular interview questions more confidently during the interview process.

Directives are reusable blocks of code that generate specific behaviors, while pipes modify user generated data before displaying it on the screen. If you are working on a large project, then knowledge of authentication & authorization methods such as OAuth2 can help you answer relevant angular interview questions during interviews more easily.

Question: What Is Angular/What Do You Know About Angular?

Firstly, you should know this angular interview questions, What is angular? Angular is an open-source front-end web application platform. It is primarily used for developing single-page applications and progressive web applications. It was created by Google in 2010 to address the challenges posed by single-page web applications. Angular has a powerful Command Line Interface (CLI) that can help you quickly scaffold, generate components, services, pipes,s and more. Some common Angular interview questions are: 

These are common Angular interview questions that are usually asked by interviewers

 

1. What is the Angular Framework? 

Angular is a typescript-based framework created by Google and released in 2010. It enables developers to build mobile, web, and desktop applications using HTML, JavaScript, and CSS. Angular offers a powerful platform for building dynamic web pages quickly and efficiently. It uses two-way data binding along with dependency injection to keep code clean and maintainable. Angular provides components that can be used across multiple projects, as well as built-in services such as animations, routing, form validation, HTTP requests, and more. Additionally, it includes tools like debugging support, which makes development easier. With the help of an angular CLI command line interface, developers can easily deploy their applications on different platforms, such as Firebase or Heroku, with minimal effort.

 

Note: It is one of the important Angular interview questions.

1. How does data binding work in Angular?  

Data binding in Angular is a mechanism to synchronize data between the model, view, and component. Data binding works by connecting the view layer of an application with its underlying data layer. This connection allows changes in one layer to be automatically reflected in another.

 

In Angular, data binding is accomplished through a combination of interpolation and property bindings. Interpolation is used for displaying data from the application’s model directly into the HTML template. Property bindings are used for updating values from the model into HTML element properties, such as <input> or <select>. 

 

For example: If we have two-way data binding [ngModel]=”data” , it means that anything we type in that textbox will be stored in “data” variable and if there is any change on this variable, it will reflect back to that textbox automatically without user intervention, i.e., whenever you change value inside controller/component class, it reflects on UI (view) and vice versa without any explicit input or action taken by developer explicitly, like calling setter methods, etc.

 

Note: It is one of the important Angular interview questions.

1. Can You Think of Any Disadvantages to Using Angular?

1. Angular applications can be slow to load due to the runtime JavaScript download and complex navigation elements. 
2. Learnability As Angular is a large and complex framework, it can take a while for developers to get up to speed with it and be able to use it effectively in their projects. 
3. Since Angular uses two-way data binding, changes made on client-side models may have unexpected effects throughout the architecture, leading to undesirable results that are hard to debug (known as “spaghetti code”). 
4. Poor performance when dealing with large data sets – since Angular processes all data on the client side, its performance suffers when working with huge amounts of information at once. 
5. Security issues – as most of the application code is visible in plain text form in the browser’s inspector window or source files, this could lead malicious users to find There are several ways of attacking the application by exploiting certain vulnerabilities inherent in JavaScript language features (like object prototype mutation).

 

Note: It is one of the important Angular interview questions.

1. How Is Dependency Injection (DI) Done in Angular?

Dependency injection (DI) is a design pattern used to implement inversion of control (IoC). Dependency injection is done in Angular using the IVFInjection() decorator. This decorator allows you to inject dependencies into components, services, and other classes. The IVFInjection() decorator is used with a class constructor argument; it allows the injector to supply an appropriate instance of the dependency when instantiating that class. This makes it easier to reuse code and test different implementations without having to rewrite your logic or restructure your code. It also helps remove hard-coded dependencies from classes, which makes them easier to maintain and update over time.

1. What are directives in Angular, and what are the various types available?

This is one of the commonly asked Angular interview questions. Directives are instructions that Angular uses to extend the attributes and components of HTML elements. They empower the developer to create custom HTML tags and components used in the templates. The ng-directive can be implemented into many different parts of an application, such as controller functions, scopes, etc. There are various types of directives available in Angular, which include:

 

1. Component Directives: These directives allow us to create reusable components with their own logic that can also control their view control using inputiv/@Output bindings and a <ng-template>. Examples include <my-component>,<button> etc. 
2. Attribute Directives: These directives change or modify normal DOM element behavior, such as not granting access to certain sections of the page, among other things, when applied to them. Examples include <input type=”date”>, <div hidden=”true”></div> etc.
3. Structural Directives: Structural directives alter layout by building conditional statements for displaying or hiding parts of UI based on certain conditions, like *ngIf=” someExpression ”; *ngFor=” let item of items “;etc.   
4. Form Validation Directive : It allows easy form validation by validating multiple values entered in form fields without having any significant set up work needed. Example include email validation , password checks, etc.  

5 Link function Directive : This directive is used for attaching functionality to already existing DOM elements. Example includes jQueryy functionalities being included after page loads.

 Note: It is one of the important Angular interview questions.

1. How do you debug an application built with Angular? 

Debugging an application built with Angular can be done in a variety of ways. The most common is to use the Chrome Developer Tools, which allow you to view and modify the code while the application is running. Other tools available for debugging an Angular app include NgRx DevTools, which provide you with a tool panel for debugging Redux-based applications; Augury, a JavaScript debugger for analyzing applications written in TypeScript or Java Script; and Batarangle, which enables developers to debug their configuration settings within their applications. It is also possible to use logging libraries like Winston or Bunyan for debugging an Angular application as well. Finally, when all else fails, it’s always possible to set breakpoints and step through your code line by line to identify where it’s failing.

 

Note: It is one of the important Angular interview questions.

1. Explain the use of ngFor directive in detail with an example code snippet? 

Example Code Snippet:

 

<ul>   

    <li *ngFor=”let x of list; let i = index”>{{i+1}} – {{x}}</li>   

</ul>

 

This code snippet will output each element of list into its own li tag inside an unordered HTML list (ul). The example uses two parameters for each iteration: one for accessing the value directly via ‘x’, and another for assigning new indexes starting from’1′ instead of ‘0’. So, if your list contains three entries “Apple,” “Banana,” and “Cucumber,” this expression will output them like this:  

 

1 – Apple\2 – Banana\3 – Cucumber

 

Note: It is one of the important Angular interview questions.

1. How would you implement routing and navigation within your app using either hash strategy or HTML5 history API approach?  

Hash Strategy:

 

To implement routing and navigation with a hash strategy, one of the popular libraries to use is Angular’s ngRoute module. It enables developers to configure route paths for the application in an easy-to-use manner. The ngRoute module maps hash URLs with configuration objects that provide information on what views and controllers to invoke when a given URL hash is encountered by the system. To set up routing using this approach, you would first need to include the angular-route.js script in your HTML page and declare it as a dependency in your app module:

var app = angular.module(‘myApp’, [‘ngRoute’]); 

Secondly, create a configuration object containing key-value pairs consisting of route paths along with their respective controllers/views like so : 

$routeProvider

  .when(‘/’, {

    templateUrl: ‘views/homepageview.html’, 

    controller: ‘HomeController’  //controller name goes here       }) 

 

 Lastly, register your routes during run time execution like this –  $routeProvider     .otherwise({redirectTo: ‘/’}); // redirect all other routes to homepage  

 

 This will enable Angular to be notified each time there’s a change in location so it can update the view accordingly, which produces the desired results for navigational purposes via URL hashes. 

 

 HTML5 History API Approach:

 

Similarly, implementing routing and navigation within an app via the HTML5 History API approach often involves the usage of another library, such as ui-router; which provides child states under parent states as well as facilitates nested views & complex state management scenarios through its’states’ concept (which is useful especially if we want our urls to appear more descriptive than just plainly showing them based off a predetermined route path setup).

 

1. Differentiate Between Javascript Modules and Ngmodules.

The main difference between Javascript modules and Ngmodules is that the former only supports code grouping, whereas the latter offers more features like code separation, lazy loading, configuring service providers within the module itself, etc. In addition to this difference in functionalities, another key distinction lies in how they are defined: while Javascript modules use exports and imports for defining their components and inter-module dependencies, respectively, Ngmodules leverage declarations, imports,imports & exports as well as bootstrapping logic.

 

Note: It is one of the important Angular interview questions.

1. What is ZoneJS, and how does it work internally within Angular?

Zone.js is a library used to patch the browser and Node.js APIs for better compatibility, control, and performance when running Angular applications. Specifically, it provides an execution context (zone) that tracks tasks as they execute across different browser APIs, like setTimeout or XMLHttpRequest. This enables developers to write asynchronous code (such as AJAX calls) without having to think about callbacks and how their code interacts with other code on the page; ZoneJS takes care of this process for them automatically by controlling any operations that could have an effect on their application’s execution flow: setTimeout(), setInterval(), AJAX requests, promises, etc.

 

Note: It is one of the important Angular interview questions.

1. What are the Router Navigation Events?

Router navigation events are a set of events that occur during a successful navigation cycle. These events include guards and resolvers, where data can be fetched, permissions can be checked, or the navigation can be cancelled. The following is a list of Router Navigation Events: 

 

1. How Can You Disable All the Animations in Angular?

Disabling all animations in an Angular application is a fairly straightforward process. To do this, we need to use the BrowserAnimationsModule that comes with the regular @angular/core package. The BrowserAnimationsModule has two options for disabling animation:

 

1) Set an empty object as the value of the window. disableAnimations:

This will disable all animation on all elements in the application. It is important to note that this setting only applies to the current browser instance and must be set again each time after refreshing or reopening the browser. 

 

2) Setting NoopAnimationsModule as a provider inside your app module:

By doing so, we are telling Angular that it should not attempt to load any animations at all and instead just bypass them completely. This can be especially useful when debugging, as no animation-related code will be executed, thus reducing clutter in our console logs. 

 

It is important to note that for both scenarios, any custom animations created using AnimationBuilder or similar methods will still remain active since those are not affected by either of these settings and must be disabled manually if needed.

 

Note: It is one of the important Angular interview questions.

1. Explain the Features of Forms in Angular.

Forms in Angular provide a convenient way of capturing data from users and sending it to the backend application. The Forms package provides numerous features that make it easier for developers to create forms, validate user input, and display results.

 

1) Built-in Validation: Forms in Angular come preloaded with validation logic against common patterns like email addresses, URLs, phone numbers, etc. This helps reduce development time by eliminating the need for writing your own custom validation code. It also improves the user experience, as invalid inputs are automatically highlighted for quick correction.

 

2) Advanced Reactive Forms: Reactive forms allow developers to build complex forms using a reactive programming model. This is especially beneficial when building large or dynamic forms, as it allows you to track changes made by users in real time and respond accordingly with dynamic updates that change form elements on-the-fly based on user input values. It also enables developers to integrate reactive streams into their forms so they can capture triggering events from other components and respond accordingly within their form controls. 

 

3) Optimized Performance: Angular’s Forms package provides optimized performance out of the box by intelligently rendering only the required DOM elements needed for each step of the form process instead of re-rendering all elements after every change made by an end user. This makes interacting with forms much faster than traditional approach often seen with other frameworks, which re-renders entire page after every update made by an end user on a form control element 

 

4) Cross Browser Compatibility: The Angular Forms package works across different browsers without any extra effort from developers, allowing them to focus solely on creating their desired functionality within their applications instead of worrying about compatibility issues between multiple web browsers during development time.

 

1. What Is a Bootstrapping Module in Angular?

A Bootstrapping Module in Angular is a module that acts as the starting point for an Angular application. It can be used to define routes and services, provide configuration for dependency injection, create components, and set up the root component of an application. The bootstrapping process happens when an application first loads and starts running. The NgModule class is used to declare a ‘BootstrapModule’ that includes other modules, directives, components such as page-level components, services, or pipes declared by other modules. Bootstrapping a module is essential for any Angular application, as it allows developers to configure their applications before they launch.

 

Note: It is one of the important Angular interview questions.

1. What Is an Angular Library? Can You Create Your Own Library in Angular?

An Angular library is a collection of code (or scripts) written in the JavaScript programming language that is commonly used within the Angular web framework. These libraries provide useful functions and methods that can be leveraged to build powerful applications quickly and easily. The core may also include other frameworks such as jQuery, React, or Vue.js, which are often used to extend functionality within an application.

 

Yes, you can create your own library in Angular. There are several steps involved, including selecting a suitable package manager tool such as NPM or Yarn, setting up your project file structure with all the necessary files and folders, creating an empty library package file for storing its contents, and eventually writing code for components that can be imported from the main application into a new module. Additionally, it might be helpful to use external tools such as Webpacker or Rollup for production-grade development workflows so users can access ready-made bundles of your libary’s source code easily without having to make changes manually themselves each time they update their system configuration or add new features to their project.

 

We have created a note mark for important Angular interview questions, but you should know all Angular interview questions for future and much better results in your interview.

Tips for Succeeding at an Angular Interview

All the Angular interview questions above are important, and this will help you in your Angular interview. 

Are you looking to ace your upcoming Angular interview? Whether you’re a seasoned veteran or a newbie to the tech world, knowing how to answer Angular interview questions correctly can be the difference between landing that gig or having your resume tossed into the “no” pile. To help you succeed in an Angular interview, we have put together some tips that are essential for any job seeker.

The first tip we recommend is researching common angular interview questions. There are a number of resources available online that provide helpful insight into what types of angular interview questions employers typically ask and what skills they look for in applicants. Knowing exactly what to expect during an angular interview will help ensure that you’re prepared with answers to all angular interview questions.

Once you have a good understanding of the types of angular interview questions asked during an angular interview, you will want to make sure your technical skills are uptodate. Reviewing all aspects of the Angular framework and brushing up on fundamentals such as HTML, CSS, and JavaScript will help to demonstrate proficiency in the language needed for success. Additionally, practicing coding exercises using frameworks such as React or Vue can make it much easier to answer coding related questions without stress.

Lastly, don’t forget to focus on yourself as well! Even if you feel confident in your technical skill level, it is important not to overlook the personal side of interviewing. Make sure you’re engaging with employers during interviews by asking questions related to their company culture and future opportunities for growth. Doing this will go a long way in showing employers that you are invested in the position and eager for success!

By following these simple steps, you’ll be well equipped with everything needed for a successful Angular interview! Good luck

Conclusion

Now that you’ve examined some of the most common angular interview questions, you should have a better idea of how to present yourself in an interview and how to better prepare for one. It’s important to remember that the interviewer is looking for enthusiasm in your answers as well as a solid understanding of the fundamentals of angular. Summarizing, when preparing for an angular interview, it’s essential to be knowledgeable about basic concepts such as components, routes, services, directives, and observables. You should also be familiar with commonly used libraries or frameworks like Angular Material and RxJS. Additionally, illustrating your knowledge using relevant examples can help you stand out from other candidates. All these aspects will help you ace your interview and gain a competitive edge over your peers.

We hope this will help you understand the angular interview questions, and then you will be able to clear the angular interview.