Angular has grown in popularity as a framework for developing front-end web applications. This collection of Angular interview questions will undoubtedly come in handy during your interview.
1.In Angular, what are pipes?
ANS:Pipes are basic functions that receive an input value, process it, and return an altered value as an output, in a more technical sense. Angular has a number of built-in pipes. You may, however, make bespoke pipes to meet your specific requirements.
2.In Angular, what are directives?
ANS:Directives are characteristics that enable users to create custom HTML syntax for their applications. When the Angular compiler discovers them in the DOM, they are executed. Three different sorts of directives are supported by Angular.
Directives for Components
Directives Structural
Attribute Directives are a kind of attribute directive.
3.In Angular, what are annotations?
ANS:In Angular, annotations are utilised to create an annotation array. They are the metadata that is placed on the class to represent the Metadata library.
4.In Angular, what are templates?
ANS:HTML containing Angular-specific elements and attributes is used to create Angular Templates. These templates are further generated in conjunction with the model and controller information to create a dynamic view to the user.
5.Mention a few Angular benefits.
The following are some of the most prevalent Angular benefits:
Angular is a full-fledged MVC framework with an MVC architecture. It expresses a strong opinion about the structure of the application. It also supports bi-directional data flow and keeps the real DOM up to date.
Modules: Angular includes design patterns like as components, directives, pipelines, and services that aid in the development of applications.
Dependency injection: This feature makes it simple to work with components that are dependant on other components.
Clean and manageable code, unit testing, reusable components, data binding, and a good responsive experience are some of the other general benefits.
6.In Angular, what are decorators?
ANS:Decorators are design patterns or methods that determine the behaviour of Angular features. They're used to make changes to a class, service, or filter before they're utilised. Angular supports four different types of decorators:
Decorators for the upper classes
Interior Designers
Decorators by Method
Decorators of Parameters
7.What are Single Page Applications (SPA)?
ANS:Single-page applications (SPAs) are web applications that are only one page long.
Single-page apps are online applications that only load once and add additional functionality via user interface enhancements. It generates dynamically rather than loading new HTML pages to display the new page's content. The ability of JavaScript to alter the DOM components on the existing page makes this feasible. A SPA method is speedier, resulting in a more consistent user experience.
8.What is data binding and how does it work? Angular uses which form of data binding?
ANS:Data binding is a phenomena that allows anybody with a Web browser to alter Web page components. It makes advantage of dynamic HTML and doesn't necessitate any scripting or programming. Data binding is used in web sites with interactive elements including forms, calculators, tutorials, and games. When pages include a large quantity of data, incremental display of a webpage makes data binding easier.
The two-way binding is used by Angular. Any changes to the user interface are reflected in the model state that corresponds to them. Changes in the model state, on the other hand, are reflected in the UI state.
9.What is TypeScript, exactly?
ANS:TypeScript is a JavaScript superset with great consistency. It comes highly recommended since it adds some syntactic sugar to the code base and makes it easier to comprehend and manage. Finally, TypeScript code is converted to JavaScript, which may execute in any environment.
10.What exactly is Angular? What was the purpose of its introduction?
ANS:Angular was created to make Single Page Applications (SPAs). This framework provides online applications with structure and consistency, as well as outstanding scalability and maintainability.
Angular is a TypeScript-based JavaScript framework that is open-source. It expresses the components of your programme using HTML syntax.\
11.How do I upgrade to Angular 9?
ANS:To upgrade your project to Angular 9, follow these steps. For a better updating experience, first upgrade your project to the latest release of Angular 8.
12.What are the new 'providedIn' options in Angular 9?
ANS:The @Injectable decorator is used to add Angular services to the injector. Angular 9 adds two new ways to inject services using existing extra options, as seen below.
You can provide providedIn:'platform' when all apps on that page share a singleton platform injector and you want a service to be available in that.
providedIn:'any' - You may provide providedIn:'any' if you want a unique instance in every module (including lazy modules) that injects the token.
13.What are the new features in Angular 9's IDE and language service?
ANS:On the Visual Studio Marketplace, you can observe several enhancements to the Angular Language Service extension. There were a few glitches that were ironed out. Other enhancements include the following:
Grammar behaviour in TextMate that allows for syntax highlighting in both in-line and external templates.
The NgModule and Type information may be found in the hover tooltip.
You may examine the definition of templateUrl and styleUrls by clicking "Go to definition."
14.In Angular, how would you grade yourself?
ANS:When you go to an interview, the interviewer may ask you to grade yourself in a certain technology, such as Angular, thus it all depends on your Angular knowledge and expertise.
15.What were some of the difficulties you encountered when working on Angular?
ANS:This question may be technology-specific, and it is entirely dependent on your previous job experience. So all you have to do now is discuss the Angular issues you encountered in your project.
16.What was your involvement in the most recent Angular project?
ANS:It's determined by your allocated job and duties, as well as the functionality you created in your project with Angular. This is a question that is asked in almost every interview.
17.How much Angular experience do you have?
ANS:Here you may describe your overall Angular work experience.
18.In Angular 9, what are Component Harnesses?
ANS:Component testing is often based on implementation details; if a component library's implementation changes, all tests that rely on that component must be updated. However, the component harness API has the possibility of isolating or insulating a test from changes to the component's internal DOM structure.
As a result, Component Harness offers a different way to test the components. Component writers will be able to use it as part of the Component Dev Kit (CDK). Component harnesses may handle many environments since just one harness implementation can be used for both unit and end-to-end testing.
19.In Angular 9, what is Project Ivy?
ANS:Angular 9 includes Project Ivy, which provides a number of benefits, as shown below. Ivy is both a compiler and a runtime system. By default, Angular 9 lets all apps to use the Ivy compiler and runtime. The Ivy compiler and runtime have several advantages.
Reduced bundle sizes - The Ivy compiler creates less code for each angular component by eliminating unnecessary code via tree-shaking.
Faster Testing - In Angular 9, the TestBed implementation has been updated, and TestBed will no longer recompile all components during tests unless they are changed. As a result of this enhancement in TestBed, the test speed has increased by 40-50 percent.
Better Debugging -
CSS class and style binding improvements -
Type checking improvements -
Build errors improvement -
Build time improvements, AOT on by default enabled -
Internationalization improvements -
20.What is the purpose of an AOT compiler?
ANS:Because the browser can not understand Angular code directly, it must be compiled into efficient JavaScript code. During the build step, an ahead-of-time (AOT) compiler compiles the Angular and HTML code, making compiled JavaScript code accessible for the browser to download and run. The AOT compiler compiles the code during the construction step, allowing for faster browser rendering.
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