Top Angular 2 Interview Questions and Answers - Essential Guide for Job Seekers

Services allow greater separation of concerns in Angular applications. They also provide modularity by allowing developers to extract common functionalities out of components. Adding Services to Angular applications makes components free from data access code.

Service has the following features:

• Singleton, i.e. only one instance of service will exist throughout the application.
• Capable of returning data in the form of Observables and promises.
• Decorated with @Injectable() decorator

Here is the list of main building blocks of Angular 2:

• Modules
• Dependency injection
• Data binding
• Components
• Templates
• Directives
• Metadata
• Services

In actual, resolver (class) is a powerful technique which is used to achieve the best user experience when browsing between pages in the application. For the implementation of the resolver class, it is important to create a new folder called resolves. Thereafter put resolvers with same template resolveName.resolver.ts

Activatedroutesnapshot in Angular 2 is basically an immutable object which is used to represent a particular version of ActiveRoute.

For the implementation of Activatedroutesnapshot object following syntax can be used.

export class ActivatedRoute {
   /** The current snapshot of this route **/
   snapshot: ActivatedRouteSnapshot;
}

Router state represents all the state of the router as a tree of activated routes.

interface RouterState extends Tree {
   snapshot: RouterStateSnapshot
   toString(): string
}

Codelyzer refers to an open-source tool that is used to run or detect if the predefined coding guidelines are followed or not. It only performs the static code analysis in angular 2 and typescript project because all platforms follow a set of easy and conventional coding to maintain it in a better way. Codelyzer also runs on the top of tslint where its coding convention is completely defined in the tslint.json file. The developer can also run it through an angular click.

Using the angular routing command it gets easier to navigate through the view page or any other file during any tasks. One can also configure the URL to redirect any other URL and this feature can also be handled to address the problem of "404 not found". By using the location services one can go back and forward along with the page history. Its syntax is- e can use {path: '/OUR_PATH', redirectTo: ['redirectPathName']}

This is one of the most common Angular 2 interview questions.

The applications in angular 2 have an error handling option which also includes the react JS library to use the catch function. In turn, the catch function includes a link that sends information about the error handler function. under this function one can send the error as a question to console file other instances will send it back in the main program to ensure the continuation of the operation of the main program. Once it is fixed whenever the error arises it will be redirected in the browser's console.

Gulp is a mission runner that approves you to define a sequence of repeatable tasks that can be run any time you need. You can automate boring matters like the minification and uglification of your javascript or some thing else you do in order to make your code production-ready.

It is a famous library that helps you add aid for contact gestures (e.g. rotate, swipe, pan, zoom ) to your page. We will enhance a swipe-able card. Angular 2 presents a token known as HAMMER_GESTURE_CONFIG which accepts a HammerGestureConfig type.

How to install HammerJS

npm install hammerjs --save