11) What does Cli stand for, and what does it do?
It stands for Command Line Interface and is used to create an Angular application. Additionally, it helps to create an applicationâs unit and end-to-end test.
This is a technique where, instead of an entire web page being loaded and given to the user in one shot, only the wanted section gets loaded in, with the rest of content delayed until needed, if at all.
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The file is used to provide the options for Typescript that will be used for an Angular project.
5 What are observables in Angular?
An observable is a declarative way using which we can perform asynchronous tasks. Observables can be thought of as streams of data flowing from a publisher to a subscriber. They are similar to promises as they both deal with handling asynchronous requests. However, observables are considered to be a better alternative to promises as the former comes with a lot of operators that allow developers to better deal with asynchronous requests, especially if there is more than one request at a time.
Observables are preferred by many developers as they allow them to perform multiple operations such as combining two observables, mapping an observable into another observable, and even piping multiple operations through an observable to manipulate its data.
Most-Asked Angular Interview Questions and Answers
Let’s start with the basic Angular interview questions and answers for freshers.
1 What is the option to choose between inline and external template?
Usually, inline templates are used for small codes and external templates are used for comparatively bigger views. However, the choice of inline or external templates is sometimes based on organization policy, situations etc.
1 What is the purpose of ngFor directive?
Whenever it is required to repeat a part or portion of an HTML template once for each item from a collection, the ngFor directive is used. Basically it creates a template for each time as the iteration becomes easier using ngFor directive.
6 What is REST?
REST in Angular stands for Representational State Transfer. It is an API that works on the request of HTTP. Here, the requested URL points to the data that has to be processed, after which an HTTP function is used to identify the respective operation that has to be performed on the data given. The APIs that follow this method are referred to as RESTful APIs.
3 What is content projection?
In Angular, Content projection refers to a pattern where you can insert, or project, the content you want to use inside a different component. For example, consider a Card component which can accept the content provided by another component.
3 How do you perform Error handling?
In Angular, error handling can be done by writing a function using HttpClient along with catchError from RxJS.To handle errors, Angular’s HttpClient parses JSON responses and returns a JavaScript object in the observable.
7) Name the three Module Arrays
In this Angular 2 interview question, try explaining the module array, and not just naming them. Modules break your applications into logical boundaries. They are, in alphabetical order:
- Bootstrap array – Tells Angular which components to load so the functionality can be accessed
- Export array – Sends out components, directives, and pipes to be used in other modules.
- Import array – Brings in functionality from other Angular modules
Itâs a class in the Angular framework that emits custom events.