#01 Introduction to Angular | Getting Started with Angular | A Complete Angular Course

Summary

This introductory lecture to an Angular course outlines the basics of Angular, a popular JavaScript framework for creating dynamic, single-page client-side applications. The script explains that Angular provides reusable code, making it ideal for SPAs, and clarifies that it is not a programming language but a framework using languages like TypeScript or JavaScript. It also touches on the evolution of Angular, distinguishing between AngularJS and the modern Angular 2+ versions, emphasizing the benefits of using Angular for structured, maintainable, and testable applications.

Takeaways

• 😀 Angular is a JavaScript framework for building client-side applications, providing reusable code like methods, classes, and interfaces.
• 📚 Angular is used for creating single-page applications (SPAs), which load a single HTML page and dynamically update the content without full page reloads.
• 🌐 Angular is not a programming language; it's a framework that uses JavaScript or TypeScript for client-side development.
• 🔧 A framework provides a collection of predefined classes and methods that offer APIs for various operations in an application, simplifying development.
• 🚀 SPAs offer a faster and more reactive user experience because they avoid server requests for HTML content with each navigation, relying on JavaScript to update the page.
• 🔄 Traditional web applications serve different HTML pages for each URL request, whereas SPAs maintain a single HTML page and change its content dynamically.
• 🛠️ Angular offers benefits over vanilla JavaScript or jQuery, such as a loosely coupled structure, ease of maintenance, reusability, and improved testability.
• 📈 Angular simplifies the development of complex applications, addressing issues of maintainability and scalability that come with plain JavaScript or jQuery.
• 📝 AngularJS, released in 2010, was the first version of Angular and is significantly different from the current Angular (starting from version 2), which was rewritten using TypeScript.
• 📈 Angular versions post-2 follow a regular release cycle, with new versions coming out every six months, each introducing minor changes and new features.
• 🎯 The course will focus on teaching Angular 2 and later versions, not AngularJS, and the knowledge gained will be applicable to the latest versions of Angular.

Q & A

What is Angular and what is its primary use?

Angular is a popular JavaScript framework for building client-side applications. It is primarily used for creating single-page applications (SPAs) for mobile and desktop platforms.

Is Angular a programming language?

No, Angular is not a programming language. It is a framework that uses programming languages like JavaScript or TypeScript.

What is a single-page application and how does it differ from a traditional web application?

A single-page application (SPA) is an application that has only one HTML page, and the content dynamically changes based on the user's interaction without reloading the page. This differs from traditional web applications where each page navigation typically involves a new request to the server for a different HTML document.

Why would a framework like Angular be preferred over plain JavaScript or jQuery for building web applications?

Angular provides a loosely coupled structure that is easier to understand and maintain, includes utility codes for common functionalities, and makes applications more testable. As applications grow, using plain JavaScript or jQuery can become complex and hard to maintain.

What are some benefits of using Angular for building web applications?

Angular offers benefits such as reusability of predefined classes and methods, easier maintenance, improved testability, and the ability to handle complex applications more effectively than plain JavaScript or jQuery.

How does Angular facilitate making HTTP requests to a server?

Angular provides predefined classes and methods for making HTTP requests to the server, which are already tested and verified, eliminating the need to write and test this logic from scratch.

What is the difference between AngularJS and Angular?

AngularJS, released in 2010, was the first version of Angular and is quite different from the current Angular framework. Angular, starting from version 2, is a complete rewrite using TypeScript and is not just an upgrade but a different framework altogether.

What is the versioning scheme for Angular after Angular 2?

After the release of Angular 2, the Angular team adopted a versioning scheme where a new version of Angular is released every six months, with minor changes and new features.

Why might single-page applications be preferred over traditional web applications?

Single-page applications are preferred for their speed and reactivity. Since they do not require a new HTML page to be loaded from the server with each navigation, they can provide a faster and more responsive user experience.

What is the latest version of Angular mentioned in the script?

As of the recording of the script, the latest version of Angular is Angular 16.

How does the script define the term 'framework' in the context of software development?

A framework is defined as a platform for developing software applications that includes predefined classes and functions for reuse, providing APIs for performing different operations within an application.

Outlines

00:00

🚀 Introduction to Angular

The first paragraph introduces the Angular framework as a popular JavaScript framework for building client-side applications. It emphasizes Angular's role in creating single page applications (SPAs) and its use of HTML, CSS, and a programming language like TypeScript or JavaScript. The paragraph clarifies that Angular is not a programming language but a framework that facilitates the development of SPAs with reusable code. It also explains the concept of a framework and contrasts traditional multi-page web applications with SPAs, using examples like Gmail and Netflix to illustrate the SPA model.

05:02

🔍 Understanding Single Page Applications

This paragraph delves deeper into the concept of single page applications, explaining how they differ from traditional web applications. It describes the SPA model where a single HTML page is loaded and the content dynamically changes without requiring a full page reload. The paragraph highlights the benefits of SPAs, such as faster loading times and a more responsive user experience, due to the absence of server requests for new HTML content during navigation. It also discusses the advantages of using Angular over vanilla JavaScript or jQuery, including improved maintainability, testability, and the ability to handle complex applications more effectively.

10:03

📚 Angular's Evolution and Versioning

The third paragraph provides an overview of Angular's evolution, starting with AngularJS, the first version released in 2010. It explains the limitations of AngularJS and the decision to rewrite the framework from scratch in 2016, resulting in Angular 2, which is a completely different framework from AngularJS. The paragraph outlines the versioning scheme of Angular, with new versions released every six months, and clarifies the distinction between AngularJS and Angular 2+. It also mentions that the course content will focus on Angular 2 and later versions, which are collectively referred to as Angular, and not on AngularJS.

Keywords

💡Angular

Angular is a development platform for building single-page applications for mobile and desktop. It is one of the most popular JavaScript frameworks for creating client-side applications. The script emphasizes that Angular is not a programming language but a framework that uses languages like JavaScript or TypeScript. Angular provides a lot of reusable code, such as predefined methods, classes, and interfaces, which simplifies the development process by allowing developers to build upon existing code rather than starting from scratch.

💡Single Page Application (SPA)

A Single Page Application is a web application that loads a single HTML page and dynamically updates that page as the user interacts with the app. The script uses examples like Gmail and Netflix to illustrate SPAs, where the content of the page changes without requiring a full page reload. This approach enhances user experience by making the application faster and more reactive, as it avoids the need to request new HTML content from the server with each navigation.

💡JavaScript Framework

A JavaScript Framework is a platform that provides pre-built code, such as classes and methods, to facilitate the development of JavaScript applications. In the script, Angular is described as a JavaScript framework that simplifies the creation of single-page applications by offering a structured way to handle tasks like making HTTP requests to the server, which would otherwise require custom code.

💡TypeScript

TypeScript is a programming language that builds on JavaScript by adding static types. It is used in Angular applications to provide a more structured approach to coding. The script mentions TypeScript as an alternative to JavaScript when developing with Angular, highlighting its role in creating more maintainable and testable code.

💡Client-Side Application

A client-side application is a software program that runs on the user's device, such as a web browser. The script discusses Angular's use in building dynamic client-side applications, which rely on HTML, CSS, and a programming language like TypeScript or JavaScript to interact with the user and display content.

💡Reusable Code

Reusable code refers to the practice of using existing code in new projects, rather than writing new code from scratch. The script highlights Angular's provision of reusable code, such as predefined methods and classes, which streamlines the development process and reduces the potential for errors.

💡HTTP Request

An HTTP request is a message sent from the client to the server to request a resource or perform an action. In the context of the script, Angular provides predefined classes and methods for making HTTP requests, simplifying the process and ensuring that the code is tested and verified.

💡Framework

A framework in software development is a set of pre-written code that provides a structure for developing applications. The script explains that a framework like Angular includes predefined classes and functions that can be reused, which is beneficial for adding functionalities without starting from scratch.

💡Versioning

Versioning in software refers to the process of assigning a version number to different releases of a program. The script clarifies the confusion around Angular's versioning, distinguishing between AngularJS (the first version) and Angular (starting from version 2), which are fundamentally different frameworks.

💡Maintainability

Maintainability is the ease with which a software system can be modified or adapted. The script discusses the benefits of using Angular, including its ability to provide a loosely coupled structure that is easy to understand and maintain, in contrast to vanilla JavaScript or jQuery, which can become complex and hard to manage as applications grow.

💡Automated Testing

Automated testing is the use of software to control the execution of tests and the comparison of actual outcomes with predicted outcomes. The script mentions that applications built with Angular are more testable, allowing developers to easily write automated tests for various parts of the application, which is a significant advantage over using plain JavaScript or jQuery.

Highlights

Introduction to the complete Angular course, covering everything about Angular step by step.

Angular is a popular JavaScript framework for building client-side applications with reusable code.

Angular is used for creating single page applications (SPAs).

Explanation of Angular as a development platform for SPAs on mobile and desktop.

Clarification that Angular is not a programming language but a framework using languages like TypeScript or JavaScript.

Angular provides predefined classes and methods for functionalities such as HTTP requests.

Framework definition and its role in simplifying application development with reusable components.

Difference between traditional multi-page web applications and single page applications.

Single page applications have only one HTML page loaded in the browser, with dynamic content changes via JavaScript.

Advantages of SPAs, including faster loading and a more responsive user experience.

Reasons for choosing Angular over plain JavaScript or jQuery for complex applications.

Angular's benefits such as a loosely coupled structure, reusability, and improved testability.

Historical overview of Angular versions, starting with AngularJS in 2010.

AngularJS vs. Angular (2 and later) - two completely different frameworks.

Angular's versioning scheme with a new release every six months, starting from Angular 2.

Current status of AngularJS being rarely used and Angular being the framework of choice.

Course content focusing on Angular 2 and later versions, applicable to the latest Angular releases.

Transcripts

hello and welcome to the very first

lecture of this complete angular course

in this course you're going to learn

everything about angular step by step

without skipping any topic

and let's kick start this course by

having a brief overview of what angular

actually is in this lecture

angular is one of the most popular

JavaScript framework for building

client-side applications and it provides

a lot of reusable code like predefined

methods classes interfaces Etc which we

can use to create Dynamic client-side

applications generally we use angular

for creating single page applications so

in this lecture we are going to learn

what is angular what is a single page

application why you should use angular

and what are the different versions of

angular available

angular is a development platform for

building a single page application for

mobile and desktop

we use angular for building client-side

applications using HTML CSS and a

programming language like typescript or

JavaScript so remember that angular is

not a programming language in itself

like JavaScript instead it is a

framework which uses programming

language like JavaScript or typescript

so we can say that angular is a

JavaScript framework which allows us to

create single page applications

now in this definition there are two

points to note first of all angular is a

JavaScript framework it is not a

programming language it is a framework

and second we use angular for creating

single page applications

so let's try to understand what a

framework and a single page application

is

a framework is like a platform for

developing software applications a

framework can have predefined classes

and functions that can be reused to

perform and add several functionalities

which otherwise we would have to write

from scratch by our own

for example let's say we are creating a

client-side application where we are

using JavaScript as the client-side

programming language now from this

application we want to make an HTTP

request to the server and then we want

to get some response from the server now

since we are using plain JavaScript as

the programming language we are not

using any framework here in order to

achieve this we will have to write the

logic of making an HTTP request to the

server from scratch and we will also

have to test whether that logic is

working properly or not in different

scenarios but if we use a framework like

angular it already provides predefined

classes and methods for making an HTTP

request to the server these classes and

methods are already tested and verified

so we need not to worry about that stuff

also in a simple word a framework is a

collection of predefined classes and

methods which provides apis for

performing different operations when

used in an application

and angular is one such framework it

provides classes and methods which we

can reuse in our application instead of

writing them from scratch

now let's try to understand what is a

single page application but before that

let's understand how a typical web

application works so here we have a

client and a server from the client we

make a request to the server for a

particular resource in this example we

are making requests to the server for

getting the HTML of about resource so

what the server will do here is it will

send us the HTML of about page in this

case about dot HTML

if we request for contact page in that

case the server is going to return Us

contact.html in the response let's try

to understand this with a simple example

so let's say here we have a very simple

web application and currently we are in

the home page so in the URL you can see

the resource is slash home so here the

client has made a request to the server

requesting the HTML of home page and the

server sent this home.html to the client

which is then rendered by the client in

this case this home.html has been

rendered by the browser

now if I navigate to this about page

in that case you see the URL has changed

to slash about so again the client has

made a request to the server requesting

for the HTML of about page

and in the response we have received

this about.html that has been rendered

by the client

if I go to this courses page

again a request will be sent to the

server requesting for the HTML of

courses page that HTML will be sent by

the server to the client and that will

be rendered

so this is how a typical web application

works but this is not how a single page

application works

a single page application is an

application which has only one HTML page

and a perfect example of a single page

application would be Gmail and Netflix

let's try to understand what a single

page application is with an example

so here we have the same web application

currently we are in the home page you

can see in the URL the resource is slash

home and for this resource index.html

has been rendered by the client

now if I go to this about page

so now you can see in the URL the URL

has changed so now the resource is slash

about and also the view has changed but

the page is still index.html the HTML

page here has not changed

if I go to this courses page now

again you will notice that the URL has

changed so now the resource is slash

courses The View has changed but the

page is still index.html the page here

has not changed and this is what a

single page application is

in a single page application when we

navigate around the application in the

URL it will seem like we are visiting

different pages that means it will look

like different HTML documents are

requested from the server and loaded in

the browser but in reality the HTML page

never changes only the content of that

HTML page changes but it will seem like

a different page has been loaded in the

browser

so remember that in a single page

application there is only one HTML page

which gets loaded in the browser in this

example this index.html and when we

navigate around the application it's

HTML content changes the page itself

never changes

and also the content is changed by

JavaScript dynamically here whenever we

are navigating around we are not

requesting any data from the server

JavaScript is simply changing the

content based on the resource which we

have requested for it is not making any

request to the server in order to change

the view

and since we are not making any requests

to the server each time we request a new

resource you will never see this refresh

icon spin

now what is the advantage of using a

single page application why do we want

to create a single page application in

the first place

let's try to answer that

since we are using JavaScript to change

the content of the page because of this

loading a new HTML content is much

faster because here we are not reaching

out to the server to request a new piece

of HTML data every time we navigate to a

different URL and therefore this

approach allows us to create an

application which is very fast and

reactive just like a mobile application

now if you need some data from the

server you can load it in the background

without making the web page unresponsive

and once the data is loaded you can

display that data in your application

okay so a single page application is

quite fast and reactive because we are

not requesting HTML data from the server

every time we are navigating around

instead behind the scenes JavaScript

takes care of rendering the appropriate

UI based on the resource which we have

requested for and this makes single page

applications quite fast and reactive

let's now try to understand why you

might want to use angular for your next

web application project

you might say that all these things are

also possible with plain JavaScript or

jQuery then why we need a completely new

framework like angular for this

well we can certainly use JavaScript or

jQuery to do the same thing which we can

do with angular but if we are using

JavaScript or jQuery as the application

grows the application gets more and more

complex and vanilla JavaScript or jQuery

code becomes hard to maintain and we

will need a way to properly structure

our application

a lot of applications built using

vanilla JavaScript or jQuery is hard to

test

also there are some functionalities

which we will have to write from scratch

when using JavaScript or jQuery

and this is the reason why over the past

few years various Frameworks have been

built and evolved to make web

application development easier and

angular is an example of one such

framework

there are several benefits of using

angular framework for developing

applications instead of using vanilla

JavaScript or jQuery

it gives our application a Loosely

coupled structure that is easy to

understand and easy to maintain

it also brings in a lot of utility codes

which we can reuse in a lot of

applications especially when dealing

with users navigation and the browser's

history

application built with angular are more

testable we can easily write automated

tests to test various parts of our

angular application

so now you know what angular is and why

should you choose angular for creating

your client application

now over the past few years there are

several versions of angular that has

been released so let's understand what

are these versions and how they are

different

one thing that can be confusing when you

are starting with angular and when

you're learning angular is the

versioning of angular

it all started in October 2010 when the

first version of angular was released

and it was called angularjs

this version of angular was completely

different from the angular that we used

today

angularjs was created as a JavaScript

framework for building client

applications

soon it gained popularity and it was by

far the most popular JavaScript

framework available for creating web

applications back then

but this framework was not designed with

the need of today's applications in mind

plus it was overly complex

so the angularjs team had to simplify

this framework and get rid of all the

issues which it had in the year 2016

angular team decided to rewrite the

original framework from scratch using

typescript as the programming language

and instead of calling it as angularjs

they simply named it angular this

angular framework was completely

different from its predecessors that is

to angularjs

this version of angular was called as

angular 2. now angular 2 was not a

simple upgrade to previous version that

is to angularjs

it was completely Rewritten from the

ground up and it was completely

different from angular 1. angular 2 also

fixed all the issues which angular 1 had

so now we have another angular framework

which is angular 2 and remember that

angular 2 is not angularjs these two are

completely different Frameworks nowadays

angularjs is hardly in use

and since the initial release of angular

2 there are other versions of angular

which has been released over the years

for example angular 4 5 6 7 and so on by

the time I'm recording this video the

latest version of angular is angular 16.

now after the release of angular 2 the

angular team simply either has to a

versioning scheme where a new version of

angular is released every 6 months and

that new version are however not the

completely right instead they have some

minor changes of few new features also

remember that angular 2 and letter

versions of angular are simply referred

to as angular

so now we have two kinds of angular

angularjs which is the first version of

angular and angular which is angular 2

and the later versions of angular

now in this course you're going to learn

about angular that is angular 2 and the

later versions of angular and not about

angularjs

and whatever you will learn in this

course that will also apply to the

latest versions of angular

so this was a very high level overview

of what angular is why you should choose

angular and what are the different

versions of angular available

in the next lecture let's go ahead and

let's create our very first angular

project