Angular 7 Interview Questions
A list of top frequently asked Angular 7 Interview Questions and answers are given below.
1) What is Angular 7? How is it different from AngularJS?
Angular7 is the latest and recent version of Angular. AngularJS was the first version of Angular which is also known as Angular 1.0.
Angular7 is the complete rewrite of the Angular1.0. It supports two-way data binding, and some other features like ng update, ng add, Angular Elements, Angular Material + CDK Components, Angular Material Starter Components, CLI Workspaces, Library Support, Tree Shakable Providers, Animations Performance Improvements, and RxJS v6 etc.
2) What is Angular framework?
Angular is a TypeScript-based open-source web framework and a platform. It is used to build web/ mobile and desktop applications.
Main features of this framework are: Declarative templates, dependency injection, end to end tooling etc. These features make web development easy in Angular.
3) What is the difference between AngularJS and Angular?
Angular is a complete rewrite of AngularJS. It is a component-based framework in which an application is a tree of individual components.
Difference between AngularJS and Angular:
4) What is the difference between structural directive and attribute directive in Angular 7?
Structural directives are used to alter the DOM layout by removing and adding DOM elements. These directives are far better in changing the structure of the view. Examples of Structural directives are NgFor and Nglf.
Attribute Directives are used as characteristics of elements. For example, a directive such as built-in NgStyle in the template Syntax guide is an attribute directive.
5) What is the difference among "declarations", "providers" and "import" in NgModule?
Difference among declarations", "providers" and "import" in NgModule:
6) What are the key components of Angular?
Key components of Angular:
Components: Components are the basic building blocks of angular application and used to control HTML views.
Modules: Modules are the set of angular basic building blocks like component, directives, services etc. An application is divided into logical pieces and each piece of code is called as "module" and used to perform a single task.
Templates: Templates are used to represent the views of an Angular application.
Services: It is used to create components which can be shared across the entire application.
Metadata: This can be used to add more data to an Angular class.
7) Explain the Architecture overview of Angular.
Angular is the most popular web development framework for developing mobile and web applications. It uses cross platform mobile development called IONIC that's why it is not limited to web apps only.
There are 7 main building blocks of an Angular application:
The basic building blocks of an Angular application are NgModules, which provide a compilation context for components. Angular app is defined by a set of NgModules and it always has at least a root module that enables bootstrapping, and many more feature modules.
The NgModules make developers to organize an application into connected blocks of functionality.
The NgModule properties for the minimum "AppModule" generated by the CLI are as follows:
8) How would you update Angular 6 to Angular 7?
You can update Angular 6 to Angular 7 by using the following command:
9) What is the UrlSegment Interface in Angular 7?
In Angular 7, the UrlSegment interface represents a single URL segment, constructor, properties and methods like this:
The UrlSegment is a part of a URL between the two slashes and it contains a path and matrix parameters associated with the segment.
10) What is Do Bootstrap (ng Do Bootstrap) In Angular 7?
The ng Do Bootstrap is a new life-cycle hook added in Angular 7 and Do Bootstrap is an interface.
11) What are directives in Angular7?
In Angular7, directives are used to add behavior to an existing DOM element or an existing component instance.
Now this directive extends HTML element behavior with a green background as below:
12) What are components in Angular7?
Components are the basic building blocks of an Angular app formed like a tree structure. Components are subset of directives but unlike directives, components always have a template and only one component can be instantiated per an element in a template.
13) What is the difference between component and directive?
A component (@component) is a directive with a template. Some major difference between components and directives are:
14) What is a template in Angular7?
A template is a HTML view where you display your data by binding controls to Angular component's properties. You can store your component's template in one of two places. You can define it inline using the template property, or you can define the template in a separate HTML file and link to it in the component metadata using the @Component decorator's templateUrl property.
Using inline template with template syntax
Using separate template file such as app.component.html
15) What is a module?
Modules are the logical boundaries in the application. An application is divided into separate modules to separate the functionalities of the application.
For example: app.module.ts root module declared with @NgModule decorator
Here, the NgModule decorator has three options:
16) What are the new features added in Angular7?
Following is a list of new features added in Angular7:
Some more Angular7 features are:
Angular Console: It is a downloadable console to start and run Angular projects on your local machine.
@angular/fire: It is a latest update on npm, and has its first stable release for Angular7.
NativeScript: It facilitates you to make a single project that builds for both web and installed mobile.
StackBlitz: StackBlitz 2.0 is now released and includes the Angular Language Service and more features like tabbed editing.