Angular 5 Interview Questions and Answers

The Angular 5 version consists of a bunch of new features and performance-enhancing improvements in addition to multiple bug fixes to make the coding work for Angular & Javascript Developers a lot easier than its predecessor, Angular 4. Here is a list of all the features in this version:

• Switching to the AOT compiler by default.
• An Integrated watch mode
• Included type for checking in multiple templates
• Versatile and increased flexibility of metadata
• Removal of the *.ngfactory.ts files
• Improved error messages for easy fixing
• Allowing multiple exports aliases
• New “Tree Shakeable” components section
• Option for Hybrid Upgrade of Application
• Updates in the I18n (Internationalization) Pipes.

Here is a list of the building blocks of the Angular Framework

• Modules
• Components
• Templates
• Data Binding
• Metadata
• Dependency Injection
• Services
• Directives

Now, Unlike Angular 1, Angular 5 does not have a bi-directional digest cycle. In this version, any changes occurring within the component generally get propagated to all the children components present in the hierarchy through the current component.
If there is any change in one component which needs to be reflected in its parent component in the respective hierarchy, you can easily emit an event using the Event Emitter API which is native from Angular 5.
So basically, EventEmitter is defined via a class in the @angular/core module which is used equally by components and directives for emitting any custom events.

Data Binding is the process of synchronizing the model and view to enable effective communications between the components and DOM.
In Angular 5, there are four types of Data Binding

• Property Binding
• Event Binding
• Two-Way Data Binding
• Interpolation

To import a module successfully in Angular 5, we use this syntax:
import { ModuleName } from 'ModuleLocation';

In Angular 5, all the components or directives have specific lifecycle events that are being managed by the @angular/core. They are used in the creation of components, rendering it, creating and rendering their children components in the hierarchy.
These components or directives process changes as and when the multiple data-bound properties have any change, and then destroy them before the removal of their templates from the DOM. Angular 5 provides a specific set of lifecycle hooks, also known as special events that are used to tap into this lifecycle while performing operations when there is a necessity.
In addition, the constructor is used to execute all the prior lifecycle events. Each and every interface comes with a single hook method prefixed with the ng. For example, the ngOnint interface has the Oninit method which needs to be implemented into the component.