Angular 7

Angular is one of the most popular frameworks for web application development. With the release of Angular 7, it has given even more features to web developers. We have list down some popular question and answers that can help you in your interview preparation.

Q.1 What is the angular 7?

Angular 7 is a open source Javascript framework, for developing dynamic web applications like single page applications or SPA.

The main advantage of using Angular 7 being, ease of development as it uses HTML like syntax to declare various functionality of a web application.

Angular 7 is maintained by Google and is the open source Javascript framework to develop robust and easy to maintain web applications using the MVC architecture.

Angular 7 features

  • Released on Oct, 2018
  • Angular 7 supports Typescript 3.1, RxJS 6.3 and Node 10.
  • CLI Prompts helps users to explore the in-built SCSS support, routing, etc.
  • Increased application performance by to automatically removing reflect-metadata from polyfills.ts file
  • Has virtual scrolling to bind a long list of elements in small packets
  • Support for dragging and dropping items in the list using CDK
  • Can set up a budget limit of final bundle size default lower limit is 2MB and higher is 5 MB
  • updates in Angular Elements
  • support for Node 10, TypeScript3.1, and the RxJS6.3
  • Angular 7 offers Do-Bootstrap and ngDoBootstrap
  • @Output has better error handling
Q.2 What is the use of angular 7?

The use of Angular 7 is widespread. Angular 7 is used by software development companies for developing websites and web applications for their clients.

Angular 7 is used for developing dynamic web applications like single page applications or SPA.

Many organizations are also using Angular 7 to manage their web facing applications as it supports

  • data binding
  • reusable components
  • form validation
  • dependency injection

Q.3 What is the difference between angular 6 and angular 7?

The difference between angular 6 and angular 7 is in terms of features between angular 6 and angular 7.

Angular 7 is the next release after angular 6.

Angular 6 features

  • Released on April 2018
  • Improvements in tool-chain
  • removed <template> tag with “<ng-template>”
  • Changed Registering provider
  • Changes in ngModelChange event
  • ng update <package> command in CLI for app update
  • ng add command in CLI for new capability to add to app
  • complete support of Angular Elements to create an Angular component and publish it as  web component
  • supports configuration of navigation URLs within the Service Workers
  • i18n is with runtime rendering
  • New rendering engine added - Ivy


Angular 7 features

  • Released on Oct, 2018
  • Angular 7 supports Typescript 3.1, RxJS 6.3 and Node 10.
  • CLI Prompts helps users to explore the in-built SCSS support, routing, etc.
  • Increased application performance by to automatically removing reflect-metadata from polyfills.ts file
  • Has virtual scrolling to bind a long list of elements in small packets
  • Support for dragging and dropping items in the list using CDK
  • Can set up a budget limit of final bundle size default lower limit is 2MB and higher is 5 MB
  • updates in Angular Elements
  • support for Node 10, TypeScript3.1, and the RxJS6.3
  • Angular 7 offers Do-Bootstrap and ngDoBootstrap
  • @Output has better error handling


Q.4 Is angular 7 released?
Yes, Angular 7 is released. Angular 7 was released on 18th October 2018
Q.5 Is angular 7 is stable?
Yes, Angular 7 is stable. Google released the stable version of Angular 7 on 18th October 2018.
Q.6 What are new features in angular 7?

New features in Angular 7 are

  • Released on Oct, 2018
  • Angular 7 supports Typescript 3.1, RxJS 6.3 and Node 10.
  • CLI Prompts helps users to explore the in-built SCSS support, routing, etc.
  • Increased application performance by to automatically removing reflect-metadata from polyfills.ts file
  • Has virtual scrolling to bind a long list of elements in small packets
  • Support for dragging and dropping items in the list using CDK
  • Can set up a budget limit of final bundle size default lower limit is 2MB and higher is 5 MB
  • updates in Angular Elements
  • support for Node 10, TypeScript3.1, and the RxJS6.3
  • Angular 7 offers Do-Bootstrap and ngDoBootstrap
  • @Output has better error handling


Q.7 Is angular 7 open source?

Yes, angular 7 is open source Javascript framework.

It has been released under MIT License. Angular Code has been licensed under an MIT-style License.

As per MIT License -

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

 

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

Link - https://angular.io/license

Q.8 What is angular and why angular?

Angular is a open source Javascript framework, to develop software applications for internet especially dynamic web applications. Angular is used to develop single page applications or SPA.

The main advantage of using Angular being, ease of development as it uses HTML like syntax to declare various functionality of a web application.

Why Angular, because Angular makes it easy to quickly develop application  for both web and mobile. Angular hides the crude implementation and many things are provided, as

Angular offers

  • Component-based architecture offering Reusability, Maintainability
  • TypeScript giving better tooling, cleaner code, and higher scalability
  • RxJS for efficient, asynchronous programming
  • Hierarchical dependency injection
  • Ivy renderer
  • Angular Material for streamlining Material Design interface engineering
  • Seamless updates using Angular CLI
  • Angular elements
Q.9 What is angular best used for?

Angular is good for developing application for both web and mobile.  Angular  is a web open source Javascript framework from Google.

Angular is good for

  • Modular application development
  • Support for both mobile and web
  • RESTful API
  • Uses HTML type syntax and extends HTML
  • Data Binding
  • Dependency injection
  • MVC architecture
  • Directives, filters, modules, routes etc
  • Separation of data model from view and user interaction



Q.10 What is AOT in angular?

AOT in angular, refers to Ahead-of-Time (AOT) compiler.

 AOT converts Angular HTML and TypeScript into JavaScript during build phase before web browser downloads and runs that code

 Earlier, Angular used JIT compiler which ran after application is bootstrapped in the web browser. AOT did code analysis, generated code in memory.

 With AOT, Angular apps reduced requirement for change detection, or dependency injection during runtime.

Q.11 Does Google use angular?

As per Google - Angular is used in public-facing applications and sites such as Google Cloud Platform and AdWords, as well as many internal tools.

(link - https://opensource.google/projects/angular)

Google also maintains Angular.

Q.12 Is Angular JS MVC?

Yes, Angular JS MVC uses MVC architecture

MVC in AngularJS divides an application into three interconnected parts of

  • Model - It manages the data, logic and rules of the application.
  • View – is output representation of information, such as a chart or a diagram. Multiple views of the same information are possible.
  • Controller - accepts input and converts it to commands for the model or view.

Interaction of MVC in AngularJS, is as

  • Model receives user input from the controller.
  • View is the presentation of the model in a particular format.
  • Controller receives the input, optionally validates it and then passes the input to the model.
Q.13 How do I upgrade AngularJS 6 to angular 7?

Upgrade of AngularJS 6 to angular 7 can be done by the ng update command, as

ng update @angular/cli @angular/core

 

The command updates Angular 6 to Angular 7 and Angular core and CLI are updated.

Q.14 Is there any certification for angular?

Yes, there are many certification providers for angular.

You should select certification for angular by answering following questions

  • Does Hard copy or e-learning is provided?
  • Practice test for assessing oneself is given?
  • Are video demonstrations provided?
  • What is the alumni strength

Vskills provides following deliverables for angular certification

  • Online video based, e-learning LMS
  • Hard copy to candidates residing in India
  • Practice tests for assessing your knowledge
  • Government certification
  • Vast alumni strength working in reputed software companies like Accenture, Cognizant, IBM, TCS, etc
Q.15 What is angular training?

Angular training involves getting to know Angular open source Javascript framework and developing web applications and SPAs using Angular.

Angular training should also include assessment and certification of your skills and knowledge of Angular open source Javascript framework.

Vskills provides following deliverables for angular certification

  • Online video based, e-learning LMS
  • Hard copy to candidates residing in India
  • Practice tests for assessing your knowledge
  • Government certification
  • Vast alumni strength working in reputed software companies like Accenture, Cognizant, IBM, TCS, etc

Hence, Vskills Angular certification fulfills all requirements for certification on Angular and the link is -

https://www.vskills.in/certification/index.php?route=product/search&search=Angular

Links for tutorial on Angular, are

Angular 2  - https://www.vskills.in/certification/tutorial/web-development/angular-2-tutorials/

Angular 4 - https://www.vskills.in/certification/tutorial/web-development/angular-4-tutorials/


Q.16 What is Google Certification Program?

Google Certification Program is a platform by Google to showcase your skill and proficiency in various Google technologies like Android and Google cloud.

The link for Google Certification Program is - https://developers.google.com/certification

 Google Certification Program does not have certification on AngularJS or Angular.

Q.17 What certifications does Google offer?

Google offer various certifications and is at link - https://developers.google.com/certification

 Google offers certification, to showcase your skill and proficiency in various Google technologies like Android and Google cloud.

 Google Certification Program does not have certification on AngularJS or Angular.

Q.18 Are Google certifications free?

No, Google certifications are not free and Google charges for exam and certification.

Depending upon the certification, Google certifications fees has been fixed by Google.

Google Certification Program is a platform by Google to showcase your skill and proficiency in various Google technologies like Android and Google cloud.

Google Certification Program does not have certification on AngularJS or Angular.

The link for Google Certification Program is - https://developers.google.com/certification

Q.19 What is the best way to learn Angularjs?

To learn AngularJS, it the best source is from creators of AngularJS - AngularJS Documentation website - https://docs.angularjs.org/tutorial and https://www.vskills.in/certification/tutorial/web-development/angular-4-tutorials/

The website of AngularJS documentation covers all topics on AngularJS’s latest version and all related material for understanding AngularJS.

Certification is also needed to assess your knowledge of AngularJS.

Vskills provides following deliverables for angular certification

  • Online video based, e-learning LMS
  • Hard copy to candidates residing in India
  • Practice tests for assessing your knowledge
  • Government certification
  • Vast alumni strength working in reputed software companies like Accenture, Cognizant, IBM, TCS, etc
Q.20 What is angular material design?

Angular material design is

  • a design language for web and mobile apps
  • Angular material design was developed by Google in 2014.
  • Angular material design is an adaptable system of guidelines, components, and tools that support the best practices of user interface design.
  • Angular material design makes it easy for developers to customize their UI while still keeping a good-looking app interface that users are comfortable with.
  • Angular material design initial focus was touch-based mobile apps, now it extends to web design.
  • Angular material design defines the qualities that can be expressed by UI regions, surfaces, and components.
Q.21 How will you create a decorator in Angular?
Primarily there are two ways to register decorators in Angular. Such that -
1. $provide.decorator, and
2. module.decorator
Q.22 How do you differentiate between Structural and Attribute directives in Angular?
Structural directives -The Structural directives are used to alter the DOM layout by removing and adding DOM elements. This is far better in changing the structure of the view. Some of the examples of Structural directives are NgFor and Nglf.

Attribute Directives - The Attribute Directives are being used as characteristics of elements. For instance a directive such as built-in NgStyle in the template Syntax guide is an attribute directive.
Q.23 According to you what are the Core Dependencies of Angular 7?
There are two types of core dependencies: RxJS and TypeScript.
1. RxJS 6.3 - RxJS version 6.3 is used by Angular 7. It has no changes in the version from Angular 6
2. TypeScript 3.1 - TypeScript version 3.1 is used by Angular 7. It is the upgrade from the version2.9 of Angular 6.
Q.24 What do you understand by IVY Renderer and Is it supported by Angular 7?

Angular releases a new kind of rendering pipeline and view engine, given that the purpose of angular view engine is to translate the templates and components that we have written into the regular HTML and JavaScript so it is easy for the browser to read it comfortably.

Ivy is believed to be splendid for the Angular Renderer. It is supported by Angular 7.

Q.25 How can you generate a class in Angular 7 using CLI?

We can generate a class in Angular 7 using CLI by using the following code -

ng generate class [options]

ng g class [options]
Where

  • name refers the name of a class.
  • Options refer to the project name, spec value in Boolean or type of a file
Q.26 What do you understand by Bazel?

Bazel refers to a test tool just like the Make, Maven and Gradle such that it is an open-source build. Bazel primarily utilizes readable and high-level build language.

Bazel handles the project in a great number of languages and builds the product for a large number of platforms. Also it supports multiple users and large codebases over several repositories.

Q.27 How can we update to Angular 4,5, 6 to Angular 7?
Following are the steps to upgrade -
1. We first need to update the Angular version globally by inserting the latest version via the terminal: sudo npm install -g @angular/cli@latest.
2. Second step is to upgrade the version locally in your project and need to assure the altering for the new version are displayed in the package.json file ng update @angular/cli
3. When it is done, upgrade all your dependencies and dev dependencies in package.json
4. To build Angular applications, Angular-devkit was introduced in Angular 6 that needs the dependency on the CLI projects.
5. With all of this, you'll also require to upgrade the version for Typescriptnpm install typescript@2.9.2 --save-dev
6. Then, you need to relocate the configuration of angular-cli.json to angular.json ng update @angular/cli and ng update @angular/core.
7. Use this command: ng update @angular/material in case of Angular material is used.
8. The next step is the removal of deprecated RxJS 6 features npm install -g rxjs-tslint rxjs-5-to-6-migrate -p src/tsconfig.app.json
9. When it is done, uninstall rxjs-compat as it is not required for Angular npm uninstall --save rxjs-compat
10. Also change import { Observable } from 'rxjs/Observable'; to import { Observable } from 'rxjs';
11. Finally, you are able to start your Angular 7 application by using ng serve
Q.28 What are the new features in Angular 7?

Angular Elements enables to support content projection with the help of web standards for custom elements.
1. Angular Material Gets Minor Updates
2. Angular Material got better in the display that gives it an elegant look in the new update. Moreover, it also added a new homepage for the material, material.io. In this, you get tooling, design guidance, development components and stay up-to-date with the latest news.
3. In case you are using an Angular Material v7 then you observe a visual difference as library make changes to itself with the updated version of the Material design.
4. Better Accessibility for Selects - In the updated version, it includes a lot of new features to enhance accessibility for selects. It adds a new feature of the native select inside mat-form-field. It is far better and outperformed than the mat- select.
5. Both the select and mat-select are available so you can choose what you want to do.
6. Virtual Scrolling - The Component Dev Kit (CDK) is available in the market with the great virtual scrolling capabilities that the user can apply by importing the `ScrollingModule`!
7. Drag & Drop - The CDK in the new update also now recommends Drag & Drop, which possess these great hallmarks:

  • Automated render as a user moves items
  • It is new feature available only in Angular 7

8. Helper methods for reordering/transferring items in lists For reordering or transferring items in lists, you can use a helper method: moveItemInArray and transferArrayItem
9. Enhancing Application Performance
10. You will get enhanced application performance in Angular 7
11. A safeguard has come into play for the users of Angular 7. It gives a portent to new application builders when they are crossing the budget with their bundle size.  The warning occurs on 2 MB whereas an error occurs over 5 MB. But you don't need to frighten. You can change the limits simply in your angular.json file. The thing you have to do is add in a bit about the warnings and error sizes with budget details.

"budgets": [
{
"type": "initial",
"maximumWarning": "2mb",
"maximumError": "5mb"
}
]

Q.29 What do you understand by TestBed?
Angular Test Bed (ATB) is a higher level Angular Only testing framework that allows us to easily test behaviours that depend on the Angular Framework.

We still write our tests in Jasmine and run using Karma but we now have a slightly easier way to create components, handle injection, test asynchronous behaviour and interact with our application. The TestBed creates a dynamically-constructed Angular test module that emulates an Angular
Q.30 What do you understand by Redux and how is it related to an Angular app?

Redux refers to a way to manage application state and improve maintainability of asynchronicity in the application by providing a single source of truth for the application state, and a unidirectional flow of data change in the application.

ngrx/store is one implementation of Redux principles.

Q.31 What are the new features of Angular 7?
Angular has recently released its newer version Angular 7, and with this version, we got several updated as well as the new features and these are listed below -
1. CLI Prompt
2. Angular Elements
3. Updates in Angular Material
4. Virtual scrolling
5. Drag and Drop
6. Setting budgets
7. Checking bundle size
8. Ivy rendering engine
9. Typescript 3.1 supports
Q.32 What do you understand by Angular CLI?

Angular Command Line Interface is a command line tool that is used to create, initialize, scaffold and to manage the whole angular application.

We can therefore use Angular Console tool to work with the command line to generate or work with different part of the Angular application, using CLI we can manage everything using commands.

Q.33 What do you understand by Angular Console?

Angular CLI is defined as a powerful tool to develop an Angular application without following complex stuff. Angular Console is a way to achieve different command line features using a simple GUI which is completely alternative to know all of the CLI commands.

In order to download the GUI tool, you can get the executable file from here. And after downloading the tool, it will look like this.

Q.34 How can you specify the type of stylesheet using the command?

Angular 7 offers the CLI prompt where we can choose stylesheet type from the available option, but for an older version, CSS was the default format for styling the pages.

Therefore can use additional flag style to specify any other supported stylesheet type than css.

Q.35 What is the Template Expression?
Template expressions are the same expression that we use with JavaScript. But the difference is that we can use it within our Html template, so it looks like that we are using JavaScript along with Html but keep in mind that not every JavaScript expressions are supported like (new), (++) and (--).
Q.36 How do you define Data Binding in Angular?

Data binding is considered as one of the important core concepts which is used to do the communication between the component and DOM. We can also say that Data binding is a way to add/push elements into HTML Dom or pop the different elements based on the instructions given by the Component.

Various types of data binding supported in order to achieve the data bindings in Angular, are
1. One-way Binding (Interpolation, Attribute, Property, Class, Style)
2. Event Binding
3. Two-way Binding

Therefore by using these different binding mechanisms, we can easily communicate the component with the DOM element and perform various operations.

Q.37 How do we define Directive in Angular?

We can define directive in Angular as a class with the (@) decorator and duty of the directive is to modify the JavaScript classes, we can also say that it provides metadata to the class. Generally, @Decorator changes the DOM whenever any kind of actions happen and it also appears within the element tag. The component is also a directive with the template attached to it, and it has template-oriented features.

The directive in Angular can be classified as -
1. Component Directive
2. Structural Directive
3. Attribute Directive

Q.38 What do you understand by Module in Angular?

Module in Angular is considered as a very important part of the application, used to organize our angular app into a distributive manner. We can say that Modules plays an important role to structure our Angular application.

Such that each Angular application must have one parent module which is called an app module and it contains the list of different items that are -

1. Components

2. Service providers

3. Custom modules

4. Routing modules

5. Pipes

Module file group all of them into a single file; the same module will be useful for bootstrapping the application.

Q.39 What do you understand by Xmb?
XMB is defined as a key value pairs with no deeper structure. It has a mechanism for named placeholders, with descriptions and examples. The messages for any given other language must be corresponded.
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