Ember.js Interview Questions

A list of top frequently asked Ember.js interview questions and answers are given below.

1) What is Ember.js?

Ember.js is an open-source JavaScript client side framework which is used for creating web applications. It eliminates boilerplate and provides standard application architecture.

Ember.js uses the MVC (Model-View-Controller) architecture pattern.

2) What is the core concept of Ember.js?

Following are some concepts used in Ember.js:

• Store: This is a central repository and cache of all records available in an application. It can be accessed by controller and admin.
• Models: It specifies a class which defines the data of properties and behavior.
• Records: It specifies is an instance of a model which contains information that is loaded from a server.
• Adapter: It is responsible for translating requested records into the appropriate calls.
• Serializer: It is used to translate JSON data into a record object.
• Automatic Caching: It is used for caching.

3) What are the main components of Ember.js?

The main components of Ember.js are:

• Models
• The Router
• Controllers
• Views
• Components
• Templates
• Helpers

4) Who was the author of Ember.js?

Ember.js was developed by Yehuda Katz and initially released on in December 2011.

5) What are the most prominent features of Ember.js?

Most prominent features of Ember.js:

• Ember.js is an open-source JavaScript framework.
• The Ember.js applications are smaller in size compared to other JavaScript libraries.
• Ember.js has the handlebars templating library which is similar as HTML and also embeds expressions that changes the display.
• Ember.js is a flexible framework that embraces the concept of fast web page. It allows speeding up the performance of your application without reloading the whole page.
• The data binding is fully supported which creates the link between two properties and when one property changes, the other property will get update to the new value.

6) What is model object in Ember.js?

A model object is used to store persistent state within an Ember application. It specifies the data to display within the HTML.

7) What is router in Ember.js?

Router is a core feature of Ember.js. It is used to translate URL into the series of templates and also represent the state of an application.

8) What does Ember.js components specify?

The Ember.js components use the W3C web component specification and provide true encapsulation UI widgets. It contains the three main specifications as templates, shadow DOM and custom elements.

The components are declared within the data-template-name have a path name instead of plain string.

9) How Ember applications are structured?

The Ember.js applications are based on MVC (Model, View Controller) structure:

Model: It defines the data that is used within the application.

View: It modifies query and edit the data and provide user interactions.

Controller: It displays the data and capture user actions.

10) What is the use of controller in Ember.js?

Controller does following things in Ember.js:

• It decorates the model returned by the route.
• It can listen to actions performed by users.

11) What is the difference between router and route in ember.js?

Router specifies the connecting point between browser's address bar and application. It translates address into route. On the other hand route specifies a position where a user request will land after it was translated by the router. Route also specifies the data provided to the template.

12) What is Ember-data?

Ember-data is a library that is used to retrieve records from a server, store them, and update them in a browser and save them back to the server.

13) What is the use of Router and {{outlet}} tag in ember.js?

Router is used to specify all the possible states of an app and map them to URLs while {{outlet}} tag is used to build a hierarchy of sections by providing a mean for a container template to include a child template.

14) What is the use of adapter? How many types of adapters in Ember.js?

Adapters are used to query the back end. Every adapter is made up of particular back end.

Following are the two types of adapters:

Rest adapter: Rest adapter deals with JSON APIs.

LSAdapter: LSAdapter deals with local storage.

15) What is controller in Ember.js?

A controller is used to handle business logic. It can represent a section of a page or entire part of it. It is like a block of logical functionality.

16) What is serializer in Ember.js?

A serializer is responsible for turning a raw JSON(JavaScript Object Notation)payload returned from your server into a record object.

17) How to define a new ember class in Ember.js?

You can use call the extend () method on Ember.object to define a new ember class.

18) What is Enumerable in ember.js?

The enumerable is an object that contains a number of child objects, and facilitates you to work with those children using the Ember.Enumerable API.

19) What is ember.mixin class?

Ember.mixin class is used to create objects those functions and properties can be shared among other instances and classes. This is useful to share behavior between objects as well as design objects.

20) How to define view in Ember.js?

21) What is Ember.Nemspace.Class?

In Ember.js, a Namespace.Class specifies an object which contains other objects or methods such as an application or framework.

22) How to create instances in Ember.js?

The new Ember.js instances can be created when you have defined the class by calling its create() method. Any properties or methods you defined on the class will be available to instances.