AngularJS, crafted in 2009 by Google, streamlines web app creation. It enhances HTML and follows MVC, making single-page apps dynamic and scalable. It’s free, promotes clean coding, and works across browsers. Thousands of developers worldwide rely on AngularJS for creating enterprise-level web apps.
A career in this field is a great idea and going for an AngularJS course in Pune can help. Felix-IT Systems is a leading AngularJS institute in Pune that offers the best and most comprehensive AngularJS classes in Pune.
In this article, we will take a look at the most frequently asked AngularJS questions to help you prepare for the interview!
Most Commonly Asked AngularJS Questions & Answers
1. Define AngularJS and what are its key features.
- AngularJS is a JavaScript framework developed by Google for building dynamic web applications. Its key features include:
- Two-way Data Binding
- Directives
- MVC Architecture
- Dependency Injection
- Modularity
- Templates
- Routing
- Testing
- Filters
2. Explain function scope in AngularJS
In AngularJS, function scope refers to the scope of variables declared within a function. These variables are accessible only within that function and are not visible outside of it. This helps keep data and actions together, avoiding unintended clashes between different sections of the code.
3. Explain services in AngularJS
In AngularJS, services are reusable components that provide functionality across an application. They make coding easier by organizing it and providing tools for sharing data, separating logic, and connecting with outside resources. It helps developers work faster and keep things tidy.
4. What is Angular Expression? Explain the key difference between angular expressions and JavaScript expressions
An Angular expression is a snippet of code used to bind data to HTML. Unlike JavaScript expressions, Angular expressions do not support flow control statements like loops or conditionals. They’re checked in a limited space without access to outside variables or functions, concentrating on how data is connected in Angular apps.
5. How can you initialize a select box with options on page load?
To initialize a select box with options on page load, you can use JavaScript. First, select the <select> element by its ID or class, then use JavaScript to dynamically add <option> elements to it with desired values and text.
6. What are directives? Name some of the most commonly used directives in the AngularJS application
Directives in AngularJS are special markers on HTML elements that add behaviour or functionality. Common ones include ngModel for data binding, ngRepeat for iterating over lists, ngClick for handling click events, ngIf for conditional rendering, and ngShow for toggling visibility.
7. How do Angular JS routes work?
AngularJS routes use the $routeProvider service to define routes for different URLs. When a URL matches a defined route, AngularJS loads the corresponding view and controller. By updating the browser’s URL without reloading the page.
8. What is data binding in AngularJS?
Data binding in AngularJS is a feature that synchronizes the data between the model and the view automatically. Changes in the model reflect in the view, and vice versa, without the need for explicit DOM manipulation.
9. What are the benefits of AngularJS?
- Two-way data binding: Changes in the model automatically reflect in the view and vice versa.
- Modular structure: Promotes code organization and reusability.
- Dependency injection: Eases testing and enhances maintainability.
- Directives: Enables creation of custom HTML tags for enhanced functionality.
10. What are the steps for the compilation process of HTML?
- Write HTML code.
- Save the file with the “.html” extension.
- HTML is interpreted by web browsers directly.
- Open a file in a web browser to view the rendered webpage.
11. Explain the linking function and its types
In AngularJS, the linking function is part of a directive and connects the directive’s behaviour with the DOM. It comes in two types: pre-linking (executed before child elements are linked) and post-linking (executed after child elements are linked).
12. Explain the injector in AngularJS
In AngularJS, an injector is responsible for creating instances of objects, resolving their dependencies, and providing them when needed. It manages the instantiation and injection of components, services, and other AngularJS constructs.
13. What is the main difference between a link and compile in Angular.js?
- Compile function: This function serves to handle template DOM manipulation and gather all directives.
- Link function: This function is employed to register DOM listeners and perform DOM manipulation. It is typically executed after the template has been cloned.
14. What is the factory function in AngularJS?
A factory function is a way to create and configure objects or services. It returns an object or a function that can be injected into other parts of the application.
15. Explain the styling form that ngModel adds to CSS classes
ngModel doesn’t directly add styling to CSS classes. It’s an Angular directive that binds input elements to component properties, facilitating two-way data binding in Angular applications.
16. What are the characteristics of “Scope”?
The scopes in Angular offer APIs like $watch to track model mutations. This facilitates the propagation of any model alterations from outside the Angular framework to the view across the system. Scopes inherit properties from their parent scopes and allow access to shared model properties. Moreover, scopes can be nested to isolate application components. They provide the context against which expressions are evaluated.
17. What is DI (Dependency Injection) and how an object or function can get a hold of its dependencies?
Dependency Injection (DI) is a design pattern where dependencies of an object or function are injected from the outside, rather than created internally. This promotes decoupling and flexibility. Dependencies can be provided through constructor injection, setter injection, or interface injection, ensuring loose coupling and easier testing.
18. What is the use of a filter in AngularJS?
In AngularJS, filters are used to format the data displayed to users. They can modify the content of expressions in views by transforming the data before it is rendered. Filters are commonly employed for tasks such as formatting dates, converting text to uppercase, or applying custom logic to manipulate data presentation.
19. What do you know about the uppercase filter and lowercase filter in AngularJS?
In AngularJS, the uppercase and lowercase filters are used to manipulate text casing in expressions. The uppercase filter converts text to uppercase, while the lowercase filter converts text to lowercase. They are commonly applied in data binding to ensure consistent text formatting across an application’s views.
20. Explain the concept of scope hierarchy
Every Angular application comprises a single root scope, yet it can accommodate multiple child scopes. Child controllers and certain directives generate these child scopes, thereby enabling the application to host numerous scopes. As new scopes emerge, they are appended as children to their parent scope. Thereby establishing a hierarchical structure reminiscent of the DOM.
21. Who created Angular JS?
AngularJS was created by Misko Hevery and Adam Abrons at Google in 2009. It was initially released to the public in 2010 as an open-source JavaScript framework for building web applications.
22. How can you integrate AngularJS with HTML?
To integrate AngularJS with HTML, you’ll first include the AngularJS library via a <script> tag. Then, you’ll define an AngularJS module in your HTML and use directives like ng-app, ng-controller, and {{ }} expressions to bind data and behaviour.
23. What is order by the filter in AngularJS?
In AngularJS, the orderBy filter is used to sort an array by the specified expression. It takes an array and a predicate as arguments and returns a new array with the elements sorted based on the predicate.
24. What is ng-non-bindable in AngularJS?
In AngularJS, ng-non-bindable is a directive used to prevent AngularJS from compiling or binding to the contents of a particular element. It is useful when you want to display content that should not be processed by AngularJS.
25. Explain the use of double click event in AngularJS
In AngularJS, the double-click event, used with ng-dblclick, triggers actions when a user double-clicks an element, like opening a modal or editing content, making the interface more responsive.
26. Why use ng-include in AngularJS?
ng-include directive in AngularJS allows you to dynamically include external HTML files or templates within your application. It helps modularize your code, promotes reusability, and simplifies maintenance by separating concerns into smaller components.
27. How can you make an Ajax call using Angular JS?
In AngularJS, you can make an AJAX call using the $http service. Here’s a basic example:
$http.get(‘url’).then(function(response) { // handle success }, function(error) { // handle error });
28. How can you set, get, and clear cookies in AngularJS?
To set cookies in AngularJS, you can use the $cookies service’s put method. To get cookies, use the get method. To clear cookies, use the remove method. Make sure to inject $cookies into your controller or service.
29. Name the AngularJS components that can be injected as a dependency
In AngularJS, components that can be injected as dependencies include services, factories, providers, constants, values, filters, and other AngularJS modules. Dependency injection is a core feature facilitating modular and testable code in AngularJS applications.
30. What are the common Angular Global API functions?
Common Angular global API functions include platformBrowserDynamic() for bootstrapping Angular applications in the browser, enableProdMode() for enabling production mode optimizations, and NgModule() for defining Angular modules.
31. What is the syntax of the factory method in AngularJS?
In AngularJS, a factory method is defined using the .factory() function. The syntax typically involves passing a name and a factory function as parameters to the .factory() method, returning an object or a function. For example:
angular.module(‘myApp’).factory(‘myFactory’, function() {
// Factory function logic here
});
32. Name different phases of the AngularJS Scope lifecycle.
- In AngularJS, the scope lifecycle consists of several phases:
- Creation: Initialization of the scope.
- Watch registration: Setting up watches for data changes.
- Model mutation: Modification of the model.
- Scope destruction: Cleanup and removal of the scope.
33. What is the AngularJS module?
An AngularJS module is a container for different parts of an application, such as controllers, services, directives, etc. It helps organize and structure the code in a modular way.
34. Explain the differences between Angular and jQuery
Angular is a comprehensive JavaScript framework for building dynamic web applications. It uses a component-based architecture and offers features like two-way data binding, dependency injection, and routing.
jQuery, on the other hand, is a lightweight JavaScript library primarily used for DOM manipulation and simplifying AJAX requests. It provides a concise syntax for common tasks like event handling, animation, and traversal of HTML documents.
35. Define ECMAScript
ECMAScript is the standardized scripting language specification that AngularJS, a JavaScript-based framework, follows for its development, providing rules and guidelines for scripting within AngularJS applications.
AngularJS course in Pune by Felix-IT Systems
We’ve explored key AngularJS interview questions for newcomers and seasoned developers. It remains a top choice for web development across various companies, adapting to evolving needs.
By attending AngularJS classes in Pune by Felix-ITs, students can prepare themselves for a rewarding career. Felix-ITs is by far one of the most AngularJS institutes in Pune with a great learning experience. Moreover, the AngularJS institute in Pune offers placement support to the students once the AngularJS course in Pune is completed.
Enroll today in our AngularJS course in Pune for a great learning experience!