Angular 5 Interview Questions and Answers

Angular 5 is an upgraded version of angular which is much faster, smaller, and easier to use. Some of its new features are Progressive Web Application Angular Universal State Transfer API and DOM Build Optimizer tool.

AngularJS reads the HTML and compiles it into an internal representation, this reading and compiling is called bootstrapping.

When you write the code to execute the bootstrapping instead of using ng-app directive then it is called manual bootstrapping.

Service worker in Angular is used to augment a traditional web deployment to deliver a better user experience. These augmented applications have reliability and performance that is on par with natively-installed code. Adding a service worker to your application is one of the main steps in turning your application to progressive web apps. It also acts as a network proxy to intercept all the outgoing HTTP requests and chooses how to respond to them. In simple terms, a service worker is a script that runs in the browser and manages to cache for web applications.

The component routing works in Angular as whenever a user navigates to a page, Angular Router performs the following steps in order:

• it reads the browser URL the user wants to navigate to
• it applies a URL redirect (if one is defined)
• it figures out which router state corresponds to the URL
• it runs the guards that are defined in the router state
• it resolves the required data for the router state
• it activates the Angular components to display the page
• it manages navigation and repeats the steps above when a new page is requested.

 NPM stands for node package manager. It is used for installing dependencies for javascript packages.

Angular CLI is Command Line Interface for Angular that runs Webpack.You can use npm install -g @angular/cli command to install angular CLI.

After installing Angular CLI run ng new project-name command to create a new Angular project.

Decorators are functions that adds metadata to class members and functions. It was proposed in ES2016 and implemented in Typescript.

Angular 5 supports four types of Data Binding They are

• String Interpolation
• Property Binding
• Event Binding
• Two-way-binding

ng serve command is used to run Angular5 application locally during development. To start development server on specific port ng serve -p aPortNumber command is used.

Also, Read Best  Angular 2 interview questions 2017

Angular5 component is made of a Component decorator and a component definition of a class. ng generate component component_name command is used to generate a component in Angular5.

Simply use below syntax to import a module in Angular5.

	import { ModuleName } from 'someWhere';
	

In Angular5 $event is a reserved keyword that represents the data emitted by an event (event data).It is commonly used as a parameter for event based methods.

 double curly brackets like {{}} are used form data interpolation in Angular5.

*ngFor directive is used for Iterating over a list of items and for Generating a new DOM element for each one.

Webpack is module bundler Bundler for Angular2 or above. It bundles, minifies and transpiles an Angular application.

Transpiling is a process of converting code from one language to another. In Angular, Traceur compiler is used for converting TypeScript to JavaScript so that browsers can understand.

Also, Read Interview questions asked in React Js  Interviews

 In Angular component life cycle in Angular goes through the following stages.

• Create
• Render
• Create and render children
• Check for bound data changes and re-render
• Destroy

NgModule is a decorator function in Angular that takes a single metadata object whose properties describe the module.