Angular Interview Question Set 10
Categories: Angular
What is HttpClient, and what are the advantages of it?
Most front-end applications use either XMLHttpRequest interface or the fetch() API to communicate with backend services over HTTP protocol. For the same purpose, Angular provides a simplified client HTTP API known as HttpClient. This is based on top of XMLHttpRequest interface. This HttpClient is available in the @angular/common/http package, which you can import in your root module as follows:
import { HttpClientModule } from '@angular/common/http';
Following are some of the crucial advantages of HttpClient:
HttpClient contains testability features.
- It provides typed request and response objects.
- It can intercept requests and responses.
By default, Angular uses client-side rendering for its applications. Is it possible to make an Angular application to render on the server-side?
Yes, it is possible to make an Angular application to render on the server-side. Angular provides a technology called Angular Universal that can be used to render applications on the server-side.
The crucial advantages of using Angular Universal are as follows:
- Making an Angular application render on the server-side can provide a better user experience. By using this, first-time users can instantly see a view of the application. So, it can be used to provide better UI.
- It can lead to a better SEO for your application. The reason is that many search engines expect pages in plain HTML. So, Angular Universal can ensure that your content is available on every search engine, and it is good for better SEO.
What is the best way to perform Error handling in Angular?
Error is when the request fails on the server or fails to reach the server due to network issues. In this condition, HttpClient returns an error object instead of a successful response. To resolve this issue, we must handle the component by passing the error object as a second callback to the subscribe() method.
What do you understand by Angular bootstrapping?
Angular bootstrapping is nothing but to allow developers to initialize or start the Angular application. Angular supports two types of bootstrapping:
- Manual bootstrapping
- Automatic bootstrapping
Manual bootstrapping: Manual bootstrapping provides more control to developers and facilitates them regarding how and when they need to initialize the Angular app. It is useful when professionals wish to perform other tasks and operations before Angular compiles the page.
Automatic bootstrapping: As the name specifies, automatic bootstrapping is started automatically to start the Angular app. The developers need to add the ng-app directive to the application's root if they want Angular to bootstrap the application automatically.
What is the digest cycle process in Angular?
The digest cycle process in Angular is the process that is used to monitor the watchlist to track changes in the watch variable value. There is a comparison between the present and the previous versions of the scope model values in each digest cycle.
What are the key differences between a Component and a Directive in Angular?
A Component is a directive that uses shadow DOM to create encapsulated visual behavior. Usually, components are used to create UI widgets by breaking up the application into smaller parts. In short, we can say that a component (@component) is a directive-with-a-template.
What do you understand by Angular MVVM architecture?
The MVVM architecture or Model-View-ViewModel architecture is a software architectural pattern that provides a facility to developers to separate the development of the graphical user interface (the View) from the development of the business logic or back-end logic (the Model). By using this architecture, the view is not dependent on any specific model platform.
The Angular MVVM architecture consists of the following three parts:
- Model
- View
- ViewModel