Introduction to Angular 5 Interview Questions and Answers

Angular is a very popular framework in terms of HTML or Javascript client-based application. This framework helps for building one of the client application which can be developed by using HTML or javascript or different kind of language call typescript which complies in a javascript environment. Normally if a developer plan to develop one single page application (SPA) then prefer to use Angular JS.

Angular mainly best for those end users who are normally comfortable in desktop application but willing to use the same kind of features in the web application. As angular following proper module architecture, productivity always is high, also provide one tooling type environment, which given developer comfortable to work. It provides a wonderful environment for validation, routing or DI activity in a client application. Earlier performing unit testing was not possible on view or presentation layer, by using angular that can be easily reachable. As it is written in proper java, performance tuning or normal page loading performance than common popular presentation layer will always be better. One of another significant utility of using the same, develop client application through angular cannot restrict in web browsers only it also can be reusable for mobile application easily.

Compare with other versions of Angular, 5 has come with a lot of new features, wonderful help on performance improvement, and fixing some high priority bugs. It also comes with some surprising functionality or so better calls gifts for all developer who actually prefers to work on Angular specifically.

AOT was one of the big features of Angular from starting version, but it needed to be activated whereas in Angular 5 is actually a default activated for use by the developer. Till date, one specific feature was missing in angular which was watching mode, now angular 5 has been introduced watching mode features which have an effective use for the developer for debugging bugs. Angular templates were one of the most popular features till date, but type checking was not in that template for a long time, Angular 5 has come with that specific feature which is really attractive.

Now, if you are looking for a job which is related to Angular 5 then you need to prepare for the 2018 Angular 5 Interview Questions. It is true that every interview is different as per the different job profiles. Here, we have prepared the important Angular 5 Interview Questions and Answers which will help you get success in your interview.

Below are the 10 important 2018 Angular 5 interview questions and answers that are frequently asked in an interview. These questions are divided into two parts are as follows:

Part 1 – Angular 5 Interview Questions (Basic)

This first part covers basic Angular 5 Interview Questions and Answers.

Q1. What are the new features introduced in Angular 5?

Answer:
Angular 5 came with a lot of new features which help and attract developer at any point of time on Angular specific task. It also has some earlier bug fixing which also helps angular developer for smooth coding.

• AOT feature is making as a default feature.
• Activating watching mode which helps developer especially in debug.
• Introducing type checking utility for the template.
• Metadata saving and fetching utility making more advance which makes it more flexible.
• Unwanted ts file like *.ngfactory.ts has been removed permanently.
• Displaying error message are more meaningful which help angular developer on error investigation.
• Feature upgrades are more smooth then earlier.
• Introducing new Tree shakeable components help angular developer for a new feature.
• More advance in case of Hybrid upgrade application.
• Improve their performance more than earlier versions.

Q2. Provide proper generation logic of Component, Pipe, Class, Directive, Service, and Module for Angular 5?

Answer:
This is the basic Angular 5 Interview Questions asked in an interview. Please find below commands for generation of Component, Pipe, Class, Directive, Service, and Module on Angular 5. Commands are little different than earlier Angular version.

Component: – ng g component my-new-component

Pipe: – ng g pipe my-new-pipe

Class: – ng g class my-new-class

Directive: – ng g directive my-new-directive

Service: – ng g service my-new-service

Module: – ng g module my-new-module

Q3. Explain the difference between JIT Compiler and AOT Compiler?

Answer:
Please find below basic differences JIT (Just in Time) and AOT (Ahead of Time) below with details:

JIT (Just in Time):

• An application is normally compiled at runtime in the browser.
• It normally compiles application just before running not before that.
• All the files are separately compiled in case of JIT.
• If a developer change any logic in code, recompilation, and redeployment is not require, JIT will automatically compile those components in the browser at runtime and effect the changes at the time of display the same.
• It always ensuring application security part by given high preference.
• At the time of developing the application, JIT is very helpful, so it will always be preferable for running the application in the local environment.

AOT (Ahead of time):

• It ensures the application code should compile at the time of building. No runtime or browser specific dependency for the same.
• It compiles the code at runtime as well.
• For avoiding browser dependency, it can compile by command line faster on the developer system itself.
• All the written code normally compiled together, HTML CSS code is maintained separately.
• It also maintained a security part by given high preference.
• It is a secure and wonderful environment for the production build, as we can avoid runtime compilation, in production which is little risky.

Let us move to the next Angular 5 Interview Questions.

Q4. What is the proper lifecycle hooks for the application development in Angular 5?

Answer:
Angular provides verities lifecycle hooks (similar to the specific event) which help the application to execute any specific activity on event wise. Normally all the interfaces available in Angular have at least one single hook method which should start with ng, as for example, ngOnInt interface, for the same component should need to maintain or implemented OnIntit method.

• ngOnChanges
• ngOnInit
• ngDoCheck
• ngOnDestroy
• ngAfterContentInit
• ngAfterContentChecked
• ngAfterViewInit
• ngAfterViewChecked

Q5. Define core differences for Observables and Promises?

Answer:
Promises:

• It always returns a single value.
• Not possible to cancel.

Observables:

• Working with multiple values as per requirement.
• Always can be canceled.
• Support collection operators like Map, Filter.
• Following features of ES 2016.
• Using RX JS.

Part 2 – Angular 5 Interview Questions (Advanced)

Let us now have a look at the advanced Angular 5 Interview Questions.

Q6. Define exact differences between Constructors and OnInit?

Answer:
Constructors:

• It is always called as default when constructing a component.

OnInit:

• ngOnInit call after the constructor and first ngOnChanges.

Q7. Explain the logic of Event Emitters and how Angular 5 make it work?

Answer:
Event Emitter is one the class using to emit custom events.

@output() somethingchanged = new EventEmitter();

Let us move to the next Angular 5 Interview Questions.

Q8. Explain with example @Input and @Output in Angular 5?

Answer:

@Input(alias): here alias is the component name which needs binding.

Same like @Output (alias).

Q9. Explain the proper differences between components and Directives for Angular 5?

Answer:
Components are proving proper view whereas Directives don’t have.

Q10. Explain the proper differences between Activated Route and Router Route in Angular 5?

Answer:
Activated route proving details information of the route which associated with the component loaded in an outlet, Router state represents only the state.

Recommended Articles

This has been a guide to the list of Angular 5 Interview Questions and Answers so that the candidate can crackdown these Angular 5 Interview Questions easily. Here in this post, we have studied top Angular 5 Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –

1. Angular 2 Interview Questions
2. Angular 4 Interview Questions
3. Angular JS Interview Questions
4. Angular JS vs Angular 2

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