Before diving into AngularJS interview questions and answers we should have a little knowledge about what is AngularJS exactly.
While there are so many web application frameworks available in the market, developers still try to run after a framework that is cheap, sustainable and easy to code. Some of them are even open source such as AngularJS, Ruby on Rails, ASP.NET, Django, etc. But in this blog, we’ll confine ourselves to one major web application framework and that is Angular application.
These days programmers are extensively using AngularJS. There are a few features that you should remember before sitting in an interview. The points listed below will also help you in getting the AngularJS interview questions and answers right too.
Impressive Features Of AngularJs
- Angular JS is a structured and more efficient framework that can create Rich Internet Applications (RIA).
- It provides the coder with an option to write the client-side application using a JavaScript’s Model View Controller structure.
- It is open-source hence is completely free and used by countless thousands of developers around the world.
- AngularJS is licensed under the Apache license version 2.0.
These features may seem to you like theory questions but the one thing the interviewer wants to make sure is to have a candidate whose base is strong. And when you know these questions you can easily crack your AngularJS interview and hence it increases your chance of getting selected too.
Advantage of AngularJS:
Moreover, AngularJS has its advantages such as:
- AngularJS can test the code using unit testing.
- AngularJS is famous for its property of using reusable components.
- Developers can achieve more functionality using shortcodes with AngularJs.
- AngularJS supports the famous MVC (Model View Controller) structure.
- The framework uses two ways of data binding.
- AngularJS supports Client-Server communication.
- It supports animation, making it stand out from other web application frameworks.
Knowing the pros and cons of a framework you are working on, makes a good impression while you sit for the interview. Sometimes an interviewer wants to check as to why a person is working on this particular framework when there are numerous other frameworks available in the market.
These AngularJS interview questions and answers make sure that the next time you sit for an interview, you remember all the details about the framework. However, you need to be well prepared for an interview that you face while searching for a job.
Read in detail on how to prepare for an interview here.
Now without wasting any more time, let’s dive straight into Angular JS interview questions and answers.
Commonly Asked Questions AngularJS Interview Questions:
1. Explain “scope” in terms of AngularJS and why is it important?
Answer:
Scope acts as a binding force between the application controller and the view in AngularJS. It contains the application’s data and methods. AngularJS creates a different scope hierarchy for each controller and hence data methods of one $scope are not available to another controller.
2. What is the meaning of services in AngularJS, explain in brief?
Answer:
To carry out a specific task, services are used. They are the singleton objects. The services can be called controllers, directives, filters, etc.
3. Define Angular Expression in AngularJS?
Answer:
Expressions are coded snippets which are placed in bindings for example {{ expression }}
There are a few differences that make it different from the javascript expressions and these are:
- Javascript expressions are evaluated against the global window whereas, in Angular, they are evaluated against a scope object.
- You can not use Loops, conditionals or exceptions in an angular expression.
4. List all the directives used in the AngularJS application.
Answer:
It extends the HTML and acts as a marker on a DOM that directs AngularJS to attach a specified behavior to the DOM element. This is the ng-model.
5. Explain Angular.
Answer:
Angular plays a major role in the development of single-page applications or SPA. It also provides the programmer with a set of ready-to-use modules that makes it easier to develop a single page application. Plus, it also has features like built-in data streaming, modular CLI and types safety. With these features, Angular can be considered as a full-fledged web framework.
Tip:
Though this whole blog is to make the beginners prepare for AngularJS interview questions. Knowing the difference between Angular and AngularJS allows the interviewer to evaluate the candidate perfectly. So while preparing for the AngularJS interview questions and answers, don’t forget to have a look at the different versions of the framework as well as the basic syntax of the framework.
6. Explain data binding in AngularJS?
Answer:
Data binding in AngularJS is the automated flow of data between the model and view in MVC structure. There are 2 ways in AngularJS for data binding and these are:
- Data mining in classical template systems
- Data binding in angular templates
7. Explain the compilation steps in HTML?
Answer:
- The HTML code is first parsed into Document Object Model i.e DOM through the standard browser API.
- Then a compilation of the document object model is performed by calling the $complile() method.
- The scope is linked with the template by calling the linking function that is returned from step 2.
8. What are a few disadvantages of the AngularJS framework?
Answer:
AngularJS is not a secure framework. To avoid any glitches server-side authentication is necessary to keep an application safe. It is not degradable, that means if the user disables the javascript framework, then a basic page will be visible and nothing else.
9. Discuss the key difference between backbone.js and AngularJS?
Answers:
To develop an application in HTML 5, AngularJS combines various functionalities using libraries. Most of these libraries are third-party libraries. Whereas Backbone.js does its job individually without taking any help from other third-party libraries.
10. Define templates in AngularJS?
Answers:
Templates are a more furnished view that has information from both the controller and the model. They can be compressed in a single file, for example, front.html or “partials” can be used in multiple views for executing the same.
11. Explain an MVC structure?
MVC structure or in other words Model View Controller is a software design pattern. Many frameworks follow it to have a smooth transition of data while developing any web application. It has mainly 3 parts such as:
- Model: It is responsible for maintaining data and is it the lowest level of the pattern
- View: It helps in displaying a portion or complete data to the user
- Controller: It controls the interaction between the Model and the View.
12. How to use a factory method in the AngularJS framework?
Answer:
To use a factory method, we first have to define a factory and afterward assign a method to it.
var mainApp = angular.module(“mainApp”, []);
mainApp.factory(‘MathService’,
function()
{
var factory = {};
factory.multiply = function(a, b)
{
return a * b
}
return factory;
});
13. Explain what are “functions” in javascript and also how will you declare them in the code?
Answer:
Tip:
(Functions are a very important part of the javascript and most of the interviewers want to know whether the candidate knows about “functions” in javascript. So it is important to know about functions whenever you sit to prepare for AngularJS interview questions.
In javascript, functions are the fundamental building blocks. It is a procedure and is defined as a set of statements that are used to perform a task or evaluate a value. For using a function in javascript, it must be defined somewhere in the scope in angularjs from which you wish to call it.
Defining a function in javascript :
It consists of a “function” keyword which is followed by the name of the function, list of parameters passed to the functions and the statements in javascript that define the function. These should be specifically enclosed in curly brackets {..}.
For example, the below code defines a function named “addition”:
function addition(number) {
return number+number;
}
14. What do you mean by “objects” in javascript ?
Answer:
Javascript is an object-based language, so everything is an object in the language. It is more template-based in comparison to being class-based. In javascript, we can directly create an object here without creating a class first.
There are 3 different ways in which we can create an object:
- It can be using object literalBy creating an instance of Object directlyWe can use an object constructor too
Here, we will discuss the syntax one by one so that you have a fair idea about the same
- By Object Literal
Syntax: object={property1:value1,property2:value2…..propertyN:valueN}
2. Creating an instance of Object directly
Syntax: var objectname=new Object();
3.By using an object constructor
Here first, you need to create a function with arguments. This argument value is assigned in the current object by using “this” keyword. In this, “this” keyword refers to the current object.
For example :
<script>
function stud(id,name,rollno){
this.id=id;
this.name=name;
this.rollno=rollno;
}
s=new stud(110,”Vinay Khatri”, 23451 );
document.write(s.id+” “+s.name+” “+.rollno);
</script>
Output of the above code:
(110,Vinay Khatri, 23451)
15. What are HTML Elements?
Answer:
An HTML element generally contains a start tag and an end tag and content is in between the tags: <tagname>Content</tagname>
Few Examples Of HTML tags are :
- <P>: This tag is useful in enclosing a paragraph.<H>: Heading of different sizes can be written in this.<br>: This is a break tag.
Void Elements
In HTML, some tags such as <br> don’t require an enclosing tag.
16. What are the basic differences between link and compile?
Answer:
The basic requirement of link function is to register the DOM Listeners and also cite the DOM manipulation. The compile function on the other hand is basically used for collecting the directives and as well as templating DOM Manipulation.
17. What is a single page application? How can it be implemented along with Angular?
Answer:
Single Page applications are those web apps which dynamically update the HTML page as and when the users interact with the app. In SPA, the only change that happens is that the parts of the page may get refreshed. The page on the other hand is never reloaded. With this functionality, however, the trips to the server are reduced.
18. What are the various types of filters in AngularJS?
Answer:
- Number formats a number into a string.
- Lowercase formats a string into a lower case.
- Uppercase formats a string into a upper case.
- Currency formats the number into a currency format.
- Filter helps select a subset of items from within an array.
- Date formats the date to a specific format as required.
- JSON formats the object into a Json string.
- Limit reduces the array or string to a specific number of characters or elements.
19. What are the differences between Directives and Services?
Answer:
This is one of the most asked AngularJS Interview Questions and answers. One of the ways to communicate with controllers is Services. It is also possible to inject one service into another. There are other functions like logging and authentication which can also be done through Services.
Directives on the other hand are used for wrapping things like jquery plugins or creating widgets.
20. Explain what is Singleton Pattern and how do you use it?
Answer:
In order to have only one object, the singleton pattern allows the limitation of a class’ instantiation. The Singleton pattern can be enabled through the use of dependency injection and services.
These were the few important AngularJS interview questions and answers. It can be referred by beginners as well as experts too who are thinking to brush up their knowledge.
Demand In The Market
As a result of the demand in the market, every company needs developers who have inside knowledge about the framework. Therefore to work on the framework, it is important to know what kind of questions you can expect when you sit for the interview.
This set of AngularJS interview questions and answers can help you build your base as well as prepare you for your dream job too.
Conclusion
To sum up, AngularJS is one of the fastest-growing frameworks and now has a large community working online too on various platforms. Several developers are extensively using this framework in their projects. This framework is no doubt becoming every developer’s favorite because it allows you to embed animation and many other cool features too.
