Angular interview and questions answer | angular interview for experience part 1

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angular interview for #experience

Question: What is Angular?
Answer: Angular is a TypeScript-based open-source web application framework, developed and maintained by Google. It offers an easy and powerful way of building front end web-based applications.


Angular integrates a range of features like declarative templates, dependency injection, end-to-end tooling, etc. that facilitates web application development.

Question: Why was Angular introduced as a client-side framework?
Answer: Traditionally, VanillaJS and jQuery were used by developers to develop dynamic websites. As the websites became more complex with added features and functionality, it was hard for the developers to maintain the code. Moreover, there was no provision of data handling facilities across the views by jQuery. So, Angular was built to address these issues, thus, making it easier for the developers by dividing code into smaller bits of information that are known as Components in Angular.

Client-side frameworks permit the development of advanced web applications like SPAs which, if developed by VanillaJS, is a slower process.

Question: Define the ng-content Directive?
Answer: Conventional HTML elements have some content between the tags. For instance:

Question: Please explain the various features of Angular.
Answer: There are several features of Angular that make it an ideal front end JavaScript framework. Most important of them are described as follows:

Accessibility Applications
Angular allows creating accessible applications using ARIA-enabled components, built-in a11y test infrastructure, and developer guides.

Angular CLI
Angular provides support for command-line interface tools. These tools can be used for adding components, testing, instant deploying, etc.


Animation Support
Angular’s intuitive API allows the creation of high-performance, complex animation timelines with very little code.

Cross-Platform App Development
Angular can be used for building an efficient and powerful desktop, native, and progressive web apps. Angular provides support for building native mobile applications using Cordova, Ionic, or NativeScript.

Angular allows creating high performance, offline, and zero-step installation progressive web apps using modern web platform capabilities. The popular JS framework can also be used for building desktop apps for Linux, macOS, and Windows.

Code Generation
Angular is able to convert templates into highly-optimized code for modern JavaScript virtual machines.

Code Splitting
With the new Component Router, Angular apps load quickly. The Component Router offers automatic code-splitting so that only the code required to render the view that is requested by a user is loaded.

Synergy with Popular Code Editors and IDEs
Angular offers code completion, instant errors, etc. with popular source code editors and IDEs.

Templates
Allows creating UI views with a simple and powerful template syntax.

Testing
Angular lets you carry out frequent unit tests using Karma. The Protractor allows running faster scenario tests in a stable way.

Question: State some advantages of Angular over other frameworks.
Answer:

Out of box Features: Several built-in features like routing, state management, rxjs library, and HTTP services are straight out of the box services provided by Angular. So, one does not need to look for the above-stated features separately.


Declarative UI: Angular uses HTML to render the UI of an application as it is a declarative language and is much easier to use than JavaScript.

Long-term Google Support: Google plans to stick with Angular and further scale up its ecosystem as it has offered its long term support to Angular.


Question: What are Lifecycle hooks in Angular? Explain some life cycles hooks
Answer: Angular components enter its lifecycle from the time it is created to the time it is destroyed. Angular hooks provide ways to tap into these phases and trigger changes at specific phases in a lifecycle.

ngOnChanges( ): This method is called whenever one or more input properties of the component changes. The hook receives a SimpleChanges object containing the previous and current values of the property.

ngOnInit( ): This hook gets called once, after the ngOnChanges hook.

It initializes the component and sets the input properties of the component.

ngDoCheck( ): It gets called after ngOnChanges and ngOnInit and is used to detect and act on changes that cannot be detected by Angular.

We can implement our change detection algorithm in this hook.

ngAfterContentInit( ): It gets called after the first ngDoCheck hook. This hook responds after the content gets projected inside the component.

ngAfterContentChecked( ): It gets called after ngAfterContentInit and every subsequent ngDoCheck. It responds after the projected content is checked.