#06 What is TypeScript | Getting Started with Angular | A Complete Angular Course
Summary
TLDRIn this lecture, the instructor introduces TypeScript, a superset of JavaScript developed by Microsoft, often used in Angular to build dynamic client-side applications. While JavaScript is dynamically typed, TypeScript is strongly typed, allowing for better error detection during compilation. The lecture explains the advantages of TypeScript, including enhanced debugging, object-oriented features, and compatibility with JavaScript. Though this Angular course won't cover TypeScript in depth, a separate course will be available for learning TypeScript from scratch. The next lecture will focus on Angular components.
Takeaways
- π± Angular is used for creating dynamic, interactive client-side applications with HTML, CSS, and TypeScript or JavaScript.
- π TypeScript is often used in Angular applications, and it's a superset of JavaScript, meaning any valid JavaScript code is also valid in TypeScript.
- π Browsers cannot directly execute TypeScript, but it gets compiled into JavaScript, which browsers can run.
- π€ TypeScript is preferred over JavaScript because it offers additional features like being strongly typed, while JavaScript is dynamically typed.
- π TypeScript allows developers to explicitly specify data types for variables, preventing potential bugs caused by JavaScript's dynamic typing.
- π One benefit of TypeScript is catching errors at compile time instead of runtime, making applications more reliable.
- π§βπ» TypeScript includes object-oriented features like interfaces, access modifiers, fields, and generics, which JavaScript currently lacks.
- π¨βπ« If you know JavaScript, you already understand most of TypeScript, as it builds on existing JavaScript concepts.
- π The course will not cover TypeScript in-depth, but another dedicated TypeScript course will be available to learn it from scratch to advanced levels.
- π In the Angular course, the instructor will explain TypeScript features only when necessary, without a separate section on it.
Q & A
What is Angular used for?
-Angular is used for creating dynamic and interactive client-side applications by utilizing HTML, CSS, and a client-side programming language like TypeScript or JavaScript.
What programming language is primarily used in Angular?
-TypeScript is primarily used in Angular, although JavaScript can also be used since TypeScript is a superset of JavaScript.
What is TypeScript, and how does it relate to JavaScript?
-TypeScript is a free and open-source programming language developed by Microsoft. It is a superset of JavaScript, meaning any valid JavaScript code is also valid in TypeScript, but TypeScript adds additional features that are not present in JavaScript.
Do browsers understand TypeScript directly?
-No, browsers do not understand TypeScript directly. TypeScript code needs to be compiled into JavaScript, which can then be executed by the browser.
Why use TypeScript instead of JavaScript in Angular?
-TypeScript offers several advantages over JavaScript, such as strong typing, which helps prevent bugs, additional object-oriented features like interfaces and access modifiers, and the ability to catch errors at compile time rather than runtime.
What does it mean that TypeScript is strongly typed while JavaScript is dynamically typed?
-In TypeScript, you can explicitly specify the data type of a variable, meaning only data of that type can be stored in the variable. In contrast, JavaScript is dynamically typed, which means the data type of a variable is inferred based on the value assigned to it and can change over time.
Is it mandatory to specify the variable type in TypeScript?
-No, specifying the variable type in TypeScript is optional. If you do not specify a type, it behaves like JavaScript, and any type of value can be stored in the variable.
What object-oriented features does TypeScript offer that JavaScript currently lacks?
-TypeScript offers object-oriented features like interfaces, access modifiers, fields, properties, and generics, which are not available in the current version of JavaScript.
What is one key benefit of TypeScript's compilation process?
-One key benefit of TypeScript's compilation process is that it can catch errors during compilation, allowing developers to fix them before running the code or deploying it in production.
Do you need to learn TypeScript before learning Angular?
-No, you don't need to learn TypeScript before learning Angular. If you already know JavaScript, you can start learning Angular. The course will explain TypeScript features as needed, but a separate TypeScript course will be available for deeper learning.
Outlines
π» Introduction to Angular and TypeScript
In this introductory lecture, the instructor explains that Angular is used to create dynamic and interactive client-side applications using HTML, CSS, and TypeScript or JavaScript. TypeScript is the preferred programming language for most Angular applications. It is a free and open-source language developed by Microsoft, described as a superset of JavaScript, meaning any valid JavaScript code is also valid in TypeScript. While browsers don't directly understand TypeScript, it is compiled into JavaScript, which can be executed by browsers. The instructor also introduces the main question of why TypeScript is used over JavaScript, citing TypeScript's additional features and advantages.
π Advantages of TypeScript Over JavaScript
The lecture dives deeper into the reasons for choosing TypeScript over JavaScript. One key advantage is that TypeScript is strongly typed, whereas JavaScript is dynamically typed. In JavaScript, the data type of a variable is determined based on the value assigned to it, whereas in TypeScript, developers can explicitly define data types, which helps avoid bugs and makes applications more predictable and easier to debug. Additionally, TypeScript offers object-oriented features such as interfaces, access modifiers, and generics, which are not yet available in JavaScript. TypeScript also catches errors during compilation, preventing runtime issues in production.
π TypeScript Course and Angular Overview
The instructor briefly mentions that while this Angular course will not focus on TypeScript in detail, developers with a JavaScript background already have most of the foundational knowledge needed to understand TypeScript. TypeScript-specific features will be explained as necessary throughout the course. However, the instructor is also creating a separate comprehensive TypeScript course that will cover everything from basic to advanced concepts. Angular learners are encouraged to take this course in parallel if they wish to dive deeper into TypeScript.
π― Moving Forward: Creating Components in Angular
The lecture concludes with a preview of the next steps in the course. The focus will shift to learning about components in Angular and creating a new component for an Angular application. The instructor signs off by thanking the audience and setting up the next lecture, which will delve into Angular components.
Mindmap
Keywords
π‘Angular
π‘TypeScript
π‘JavaScript
π‘Strongly Typed
π‘Dynamically Typed
π‘Compilation
π‘Object-Oriented Features
π‘Superset
π‘Compile-Time Errors
π‘Client-Side Application
Highlights
Angular is used to create dynamic and interactive client-side applications using HTML, CSS, and a client-side programming language like TypeScript or JavaScript.
Although JavaScript can be used, most Angular applications are built using TypeScript, a superset of JavaScript.
TypeScript is a free and open-source programming language developed by Microsoft, and it allows any valid JavaScript code to be compiled as TypeScript.
Browsers do not understand TypeScript directly, so it needs to be compiled into JavaScript before being executed by browsers.
One of the main advantages of TypeScript over JavaScript is that it is strongly typed, whereas JavaScript is dynamically typed.
In TypeScript, data types can be explicitly defined, which helps to avoid many bugs and makes applications more predictable and easier to debug.
Specifying variable types in TypeScript is optional, but doing so makes the code more robust.
TypeScript supports additional object-oriented features such as interfaces, access modifiers, fields, properties, and generics, which are not available in current versions of JavaScript.
TypeScript allows errors to be caught at compile time, which helps to prevent issues before deploying code to production.
Developers familiar with JavaScript will already understand most of TypeScript, making the transition to learning Angular easier.
This course will not cover TypeScript in-depth, but essential TypeScript concepts will be explained as needed during the course.
A separate course will be made available for TypeScript, covering everything from beginner to advanced level.
The ability to use TypeScript in Angular development provides benefits like type checking, easier debugging, and more readable code.
Since TypeScript is a superset of JavaScript, developers can write JavaScript code and still benefit from TypeScriptβs features when compiling.
Angular developers benefit from the additional tooling and compile-time checking TypeScript offers, allowing them to catch errors early in the development process.
Transcripts
in the very first lecture of this course
we learned that we use angular for
creating Dynamic and interactive
client-side applications by using HTML
CSS and a client-side programming
language like typescript or JavaScript
now most of the time when we create an
application using angular we use
typescript as the programming language
typescript is a fairly new programming
language which is very similar to
JavaScript
so in this lecture let's understand what
typescript is and do you really need to
learn typescript first in order to learn
angular
typescript is a free and open source
programming language developed by
Microsoft and you can say that it is a
superset of JavaScript that means any
valid JavaScript code is also a valid
typescript code so if you write a valid
JavaScript code in a typescript file
that JavaScript code will be compiled by
the typescript compiler so remember that
any valid JavaScript code is also a
typescript code now here you might ask
okay we are going to use typescript in
angular to create a client-side
application but do browsers actually
understand typescript will the browser
be able to execute the typescript code
well no browsers do not understand
typescript but very important point to
note here is that when we compile our
typescript code that typescript code
gets converted into JavaScript code okay
so we are going to write our code in
typescript but when that typescript code
will be compiled it will be converted to
JavaScript
and that compiled JavaScript can be
executed by the browsers
now you might have another question so
why typescript why cannot be directly
use JavaScript
well there are several advantages of
using typescript over JavaScript first
of all as I mentioned typescript is a
superset of JavaScript that simply means
that any valid JavaScript code is also a
typescript code but typescript has
additional features which do not exist
in the current version of JavaScript
supported by most browsers available out
there for example typescript is strongly
typed but JavaScript is not strongly
typed it is dynamically typed in
JavaScript when we create a variable and
when we assign a value to that variable
we do not specify the data type for that
variable explicitly
the data type of that variable is
calculated based on the value we are
storing in it for example here in the
name variable when we are storing this
value John the data type of this name
variable will be string
in the same way to this age variable
when we are assigning it a value 28 this
28 is a number so the data type of this
age variable will be number
in the same way so this is married
variable we are assigning a Boolean
value so the data type of this is Merit
will be Boolean So based on the value
which we are assigning to the variable
the variables data type will be set and
that's why we say that JavaScript is
dynamically typed there the data type is
calculated based on the value which is
stored in the variable
but typescript is strongly typed because
in typescript we can explicitly specify
what type of data we want to store in a
variable
for example here
for the name variable we are specifying
the data type as string so in this name
variable we can only store string values
if we try to store a number value in
this name variable it will throw an
error but that is not the case in case
of JavaScript so in case of JavaScript
to this name variable I am assigning the
string value later I can also assign a
numeric value to this name variable and
it is not going to complain
okay so that's why typescript is
strongly typed because there whatever
data type we specify only that type of
data we can store in the variable
but JavaScript is not strongly typed it
is dynamically tagged in a variable we
can store a value of any data type
and since typescript is strongly typed
because of this it helps us avoid many
bugs in our application which can be
introduced due to dynamically typing now
you also need to remember here that in
typescript specifying the variable type
is optional it is not mandatory for
example here we are explicitly
specifying the data type for this name
variable as string but this is optional
this is not mandatory if I don't specify
the data type here for this name
variable just like JavaScript we can
also store any type of value in this
name variable
but if we explicitly specify the data
type for a variable this feature makes
our application more predictable and it
also makes it easier to debug them when
something goes wrong
typescript also has quite a few object
oriented features which we do not have
in JavaScript like interfaces access
modifiers Fields properties generics Etc
these features are not available in the
current version of JavaScript but they
might be introduced in the future
versions of JavaScript
another benefit of using typescript is
that we can catch errors at compile time
instead of at runtime so when compiling
the typescript code so basically there
is a compilation step involved and
during the compilation we can catch
these errors and fix them before
deploying it in the production
so typescript is a beautiful programming
language and it is basically a superset
of JavaScript any valid JavaScript code
is also a valid typescript code if you
know JavaScript then you already know
most of the typescript concepts that's
why in this course I will not talk about
typescript specifically if you know
JavaScript then you're good to take this
course the rest of the features of
typescript which is not available in the
current version of JavaScript you will
learn about it as you move along with
this course
now I am not going to talk about
typescript specifically in this course
but barely I am going to create a new
course for typescript and there I will
keep on uploading typescript related
topics
so along with learning angular from this
course you can also learn typescript
parallely from that typescript course
and in that typescript course I am going
to cover everything from scratch to
advanced level
but in this angular course since I don't
want to make it too lengthy I will not
cover the typescript topics whenever
required I will explain some of the
features of typescript but I am not
going to cover typescript as a section
in this course for that I am going to
create a separate course and you can
watch that course in order to learn
typescript
all right so this was a very brief
introduction of what is typescript
now in the next lecture let's go ahead
and let's learn about component and
let's go ahead and let's create a new
component for our angular application
this is all from this lecture thank you
for listening and have a great day
Browse More Related Video
#01 Introduction to Angular | Getting Started with Angular | A Complete Angular Course
#07 What is a Component | Angular Components & Directives| A Complete Angular Course
Week 2 Typescript
Learn TypeScript For React in 50 Minutes - React TypeScript Beginner Crash Course
#08 View Template of Component | Angular Components & Directives| A Complete Angular Course
#19 Understanding Directives | Angular Components & Directives | A Complete Angular Course
5.0 / 5 (0 votes)