Angular 4 Interview Questions and Answers

To add an external js file into Angular 4, follow these steps:

• Refer the scripts inside the angular-cli.json file like this:
  "scripts": [ "../path" ];
• Add this into typings.d.ts :
  declare var variableName:any;
• Import the above onto your js file as:
  import * as variable from 'variableName';

The JWT Interceptor is used in Angular 4 to intercept Http requests from the application itself when the user logs in to add a JWT auth token in the Authorization header. The interceptor is implemented using the HttpInterceptor class.

Note: These are basic Angular 4 interview questions and answers to provide a brief insight into Angular Development.

JIT

During compilation of code in Angular 4, Just-in-Time (JIT) compilation (also known as dynamic translation or run-time compilations) is used to execute computer code involving compilation during the run time of a program, precisely, prior to execution.

AOT

In Angular 4, Ahead-of-Time(AOT) compilation is used to convert your code during the build time before it loads on the browser. This creates a scope for faster rendering in your browser.

A Transpiler, which runs on TypeScript is used in Angular 4 to compile all the TypeScript code created in the development process and convert them into JavaScript for rendering into the browser.

When a user interacts with an Angular 4 application through keyboard movement, mouse click, or a hover, they generate an event. These events are handled in order to perform a specific action via Event Binding. Event Binding is basically one-way data binding which sends information within the view and component class.

Note: These are fundamental interview questions on angular 4 to give you an overview of the subject.

Angular Material is a User-Interface component library that is used in Angular 4 to help in developing attractive, stable and functional web pages and applications while maintaining the best practices involved such as browser portability, device independence, and graceful degradation. Its main use is to create beautiful and responsive websites that are optimized for speed in browser-rendering.

The filter is a vital aspect in AngularJS as well as Angular 4. It is the method of separating an item from a group of items inside an array or object arrays by specifying a particular type to it.

In Angular 4, the CDK stands for Component Dev Kit which is a set of tools to implement common interaction patterns throughout the code.

In Angular Material, Flex is a layout which basically is a component engine allowing you to easily create Flexbox-based page layouts with a specific set of directives available for your template. In addition, it eradicates the need for a separate styling sheet.

Following steps will provide you the proper direction to use priming in angular 4

• In order to install primeng UI libraries or primeng UT components: Install primeng using the command- npm install primeng-save
• In dependencies section include package.json
• Goes to the setting, and configure PrimeNG in app.module.ts
• Include import { DataListModule } from ‘primeng/primeng’;
• Import DataListModule and include primeng components using command bikes.component.html