Top 10 Angular Interview Questions

Angular is a Google-backed open-source framework that provides declarative templates and a code library for rapid development. With Angular, developers can create web apps using HTML, CSS, and JavaScript. This article comprises the top 10 most asked Angular Interview Questions.

1. What is Angular?

ANS: Google developed and maintains Angular, an open-source web application framework based on TypeScript. It allows you to create front-end web-based apps in a simple and powerful way.

2. Tell us about the technologies used in Angular?

ANS: Google created Angular, a modern frontend JavaScript framework. Angular makes use of a variety of technologies for a variety of reasons, including to make certain activities easier to complete and to give developers a better experience while designing applications with it. TypeScript is a superscript of JavaScript that is used by Angular. As a result, any legitimate JavaScript code is also a valid TypeScript code. However, TypeScript enables us to express JavaScript as a tightly typed language with the ability to define our own types, making problem detection considerably easier. It also makes use of RxJS, which makes it easier for developers to deal with asynchronous tasks.

3. What are the advantages of using Angular?

ANS : TypeScript is used to build Angular, allowing developers to create tightly typed code that is then transpired into JavaScript. Strongly typed code has the advantages of being easy to read, maintainable, and less prone to errors. It also comes with improved toolings, like type hints and code completion. We may use Angular to break our code into modules, which can be used to wrap functionality relevant to a certain task, such as HTTP connection, data validation, and routing. Angular includes a wide ecosystem of tools, libraries, frameworks, plugins, and other components that make the development process go much more quickly and smoothly. Angular CLI, RxJS, NgRx, and other tools and libraries are among them.

4. Define data binding?

ANS : Data binding is one of the most significant and powerful elements for communicating between the DOM and the component. It simplifies the process of creating interactive apps by eliminating the need to worry about data pushing and pulling between the component and the template.

5. Tell us about the AOT compilation in Angular?

ANS : Angular's AOT (ahead-of-time) compiler turns Angular HTML and TypeScript code into JavaScript code during the build phase, allowing for substantially faster rendering. Because Angular employs TypeScript and HTML code, this compilation step is required. The compiler turns the code to JavaScript, which the browser that runs our program may then use efficiently.

6.What do you mean by string interpolation?

ANS : Only one-way data binding is possible with Angular's string interpolation, also known as the mustache syntax. It's a unique syntax that uses double curly brackets to display component data. The JavaScript expressions that Angular must execute to retrieve the result, which can then be placed into the HTML code, are included within the braces. Furthermore, as part of the digest cycle, these expressions are updated and saved on a regular basis.

7. What are the components in Angular?

ANS : In Angular, components are the fundamental building blocks of the user interface. For a specific portion of a user interface, a component is made up of HTML, CSS, and JavaScript. These can be thought of as a special HTML element that only Angular understands. Because these components are namespaced by the compiler, styles, and code from one component do not influence other components. The Angular framework then assembles these components to create the user interface for the browser to render.

8. What are pipes in Angular?

ANS : When trying to output dynamic data in our templates, we may need to change or convert the data before putting it into the templates. Though there are other options, using pipes in Angular is the most favored method. A pipe is a simple function that we may utilize in our templates with expressions. Pipes are highly handy since they allow us to use them throughout our application after declaring and registering them with the Angular framework once. UpperCasePipe, LowerCasePipe, CurrencyPipe, and others are some of the most common built-in pipes in Angular.

9. Elaborate on why were client-side frameworks like Angular introduced?

ANS : Dynamic websites used to work by taking a template that was nothing but HTML code with places left vacant for feeding data and content into those templates before JavaScript-based client-side frameworks. This information was often retrieved from a database. We'd serve the created HTML content to the user after integrating the template and data. As you can see, it was a bit complicated, and it required a lot of processing in certain circumstances. To get over these problems, people devised a new strategy in which they deliver the data required to generate a page from their web servers to web browsers and then let JavaScript combine it with a predefined template. Since even mobile phones can now perform this type of processing, servers can now simply provide data to a client via the internet in a recognizable format, such as JSON, XML, and so on. This decreases the amount of processing that is done on the servers and improves performance.

10. Differentiate between angular decorator and annotation?

ANS: Decorators are Angular design patterns that aid in the customization or decorating of classes without requiring changes to the source code. Annotations, on the other hand, are used to create an annotation array in Angular. They are metadata set for the supplied class that uses the Reflective Metadata library.

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