Front End Developer (AngularJS) Interview Preparation Guide
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Front End Developer (AngularJS) based Frequently Asked Questions in various Front End Developer (AngularJS) job interviews by interviewer. These professional questions are here to ensures that you offer a perfect answers posed to you. So get preparation for your new job hunting

62 Front End Developer (AngularJS) Questions and Answers:

1 :: Is AngularJS a library, framework, plugin or a browser extension?

AngularJS fits the definition of a framework the best, even though it's much more lightweight than a typical framework and that's why many confuse it with a library.

2 :: Tell me what is a scope in AngularJS?

scope is an object that refers to the application model. It is the glue between application controller and the view. Both the controllers and directives have reference to the scope, but not with each other. It is an execution context for expressions and arranged in hierarchical structure. Scopes can watch expressions and propagate events.

3 :: Tell me what's Angular's performance like?

The startup time heavily depends on your network connection, state of the cache, browser used and available hardware, but typically we measure bootstrap time in tens or hundreds of milliseconds.

The runtime performance will vary depending on the number and complexity of bindings on the page as well as the speed of your backend (for apps that fetch data from the backend). Just for an illustration we typically build snappy apps with hundreds or thousands of active bindings.

4 :: Explain me who is Front End Developer? What he does?

In a website, front-end is the part that users accesses while interacting with the website including images, buttons, colours, animations, forms, typography etc.

While the frontend developer is a programmer that codes the front end of a website and ensures that a visibility of site remains same throughout different web browsers.

5 :: Tell me what is CoffeeScript?

CoffeeScript is a small programming language that compiles into JavaScript. It helps to write JavaScript code better by providing you with a more consistent syntax and avoiding the irregular nature of JavaScript language

The basic rule for Coffee Script
Whitespace matters: There are no curly braces in CoffeeScript
No parentheses: Functions that take arguments do not require parentheses

6 :: Explain difference between == and ===?

This is pretty simple but at the same time some people never came across a triple equals or never wondered what's the difference.
Double equals == is used to compare the value of two operands:

"2" == 2; // true
2 == 2; // true
Triple equals === is used to compare the value AND type of two operands:

"2" === 2; // false
2 === 2; // true

7 :: How can you add a method to a class already defined?

You can add a new method to a javascript class using prototype:

function Person(name) { = name;
Person.prototype.walk = function() {
console.debug( + " is walking.");
// Calling the new method
var person = new Person("Hussain");
person.walk(); // "Hussain is walking."
It's worth mentioning that adding methods via prototype is the most inexpensive way in terms of performance since the method is tied to the prototype of the class. It means, for every new instance of class Person, you will have access to the prototype's walk() method. Now, if you declare walk() method inside the Person class, you will end up recreating the method for every new instance of Person.

8 :: Explain me when would you use GET and POST requests?

There are several technical differences between these two types of requests, regarding length limitation, security, caching and a few others. But if someone asks you WHEN would you use it, I'd say one of the most important points that any front-end developer should take into account is that we should only use GET for idempotent requests, it means requests that don't make significant changes in the backend system or database but if you do need to make inserts, updates or deletes in a database, trigger emails or any other major action, POST is recommended.

9 :: Explain your workflow when you create a web page?

The workflow of a modern front-end developer has changed vastly in the past four or five years. A huge array of tools are available to build organized, scalable web applications by abstracting out many of the complexities and automating repetitive tasks. Each developer will share a different workflow which will give some insight into their organizational capacity and general technical preferences.

10 :: Tell me the difference between null and undefined?

null is an object that has no value. undefined is a type.