Aspire – Angular Interview Questions
Here is the list of Angular Interview Questions which are recently asked in Aspire company. These questions are included for both Freshers and Experienced professionals. Our Angular Training has Answered all the below Questions.
1. Why were client-side frameworks like Angular introduced?
Angular was designed to create dynamic web applications.It ensures building front-end-based apps without using any other plugins. To deliver the best web applications, Angular provides a lot of functionality and tools for organizing the work.
2. What are annotations in Angular ?
An annotation is a comment added to provide explanation. It is normally added to articles or to literary works. Annotation is metadata added to the Angular code.
3. What are pure Pipes?
Angular pipes are simple functions that transform the format of output data.Pure pipes are pipes that are executed when pure change is detected in the input value. It employs pure functions.
4. What do you mean by String Interpolation?
string interpolation is the process of evaluating a string literal that contains one or more placeholders. It yields a result in which the placeholders are replaced with their values.String interpolation in Angular is used to display dynamic data on an HTML template.
5. What is shadow dom?
The Shadow DOM is part of Web Components, which encapsulates styles and login of the elementto HTML Elements. Using the Shadow DOM, markup, styles, and behaviors are scoped to the element and do not clash with other nodes of the DOM
6. What is an AOT compilation in Angular?
The Angular ahead-of-time (AOT) compiler converts the Angular code into JavaScript code. The conversion happens before the browser downloads and runs the code. To achieve faster rendering in the browser, Compile your application during the build process.
7. What are modules in Angular?
A module is a mechanism or container to group the components, directives, pipes and services.It helps to encapsulate the code that deals with several aspects of an application. Developers can create modules using the NgModule decorator.
8. String inbuilt function
Function | Description |
---|---|
IsString | To identify if a reference is string. |
IsNumber | To identify if a reference is number. |
IsDate | To identify if a value is date. |
9. Service and Guard
Angular route guards are interfaces which when implemented allow us to control the accessibility of a route based on condition provided in class implementation of that interface. Five types of route guards are provided by angular:- CanActivate.
- CanActivateChild.
- CanLoad.
- CanDeactivate.
- Resolve.
10. Observable in angular
Observable are things to observe and take action on. Angular uses the Observer pattern which simply means — Observable objects are registered, and other objects observe them and take action when the observable object is acted on in some way.
11. What are the inbulit angular directives
Directives are classes that add additional behavior to elements in the Angular applications. With Angular's built-in directives, you can manage forms, lists, styles, and what users see.The different types of Angular directives arecomponents, attribute, and structural directive.
12. How to find missing number in an array
Approach: The length of the array is n-1. So the sum of all n elements, i.e sum of numbers from 1 to n can be calculated using the formula n*(n+1)/2. Now find the sum of all the elements in the array and subtract it from the sum of first n natural numbers, it will be the value of the missing element.
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13. What is the Document Object Model?
The Document Object Model (DOM) is a programming API or object oriented representation for web documents. It represents the page and allows you to make changes. The DOM follows traditional object oriented design.
14. What does Angular Material mean?
Angular Material is a User Interface component library. It is used to speed up the development of the user interfaces. Angular Material offers reusable and beautiful UI components.It allows to develop fully functional web pages,and applications.
15. What are services in the Angular framework?
A service is a class or reusable code with a well-defined purpose. It allows defining functionality that are accessible and reusable in many other components.A single service performs only a single task. One component uses several services to achieve various tasks.
16. What is a template in Angular?
A template is a form of HTML which is a blueprint for UI. It contains attributes and elements. The template represents how to render the component. It provides a dynamic view to the end user.Also, it creates a complex view in an external HTML file.
17. What is an annotation in Angular?
Annotation is a block of text or metadata set in a class to represent an object with a string. It is used to detect errors by the compiler. Annotation can be edited at run time and displayed over a node.
18. Explain the difference between angular and AngularJS?
The TypeScript that Angular uses is a superset of ES6, which has backward compatibility with ES5. Angular JS, based on JavaScript, uses terms of scope and controllers while Angular uses a hierarchy of components. Angular is component-based while AngularJS uses directives
19. What are Directives in Angular?
Directives are classes or extended custom HTML attributes to change the style or behavior to DOM elements. It can add additional behavior to elements. Angular's built-in directives are used to manage forms, lists, styles.
20. What are Pipes in the Angular context?
Pipes are simple functions that can be applied directly in a template. It can be used throughout the angular application. Pipes accept input values and return the output as transformed value. Angular supports multiple inbuilt pipes that are customizable.
21. How to find missing number in an array
var a = [5],
count = 5;
var missing = new Array();
for (vari = 1; i<= count; i++) {
if (a. indexOf(i) == -1) {
missing. push(i);}
22. Indexof() If the given value is not in the string / array it will return what?
The indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.
23. Semantic element in HTML?
A semantic element clearly describes its meaning to both the browser and the developer. Examples of non-semantic elements: