What is JavaScript?
Summary
TLDRThis video provides an insightful introduction to JavaScript, answering key questions such as what JavaScript is, its uses, where it runs, and the difference between JavaScript and ECMAScript. The video highlights JavaScript's popularity, its applications in web and mobile development, and the role of Node.js in running JavaScript outside of browsers. Additionally, it explains ECMAScript's role in standardizing JavaScript features. The tutorial includes a practical demo of writing JavaScript code in the Chrome console, offering a hands-on learning experience for viewers.
Takeaways
- 🌐 JavaScript is a highly popular programming language used globally and is experiencing rapid growth.
- 📈 Major companies like Netflix, Walmart, and PayPal use JavaScript to build internal applications, offering significant job opportunities for developers.
- 💰 JavaScript developers in the United States have an average salary of $102,000 per year, making it a lucrative career choice.
- 🔄 JavaScript can be used for front-end, back-end, and full-stack development, offering versatility in web development roles.
- 🚀 JavaScript was initially used for building interactive web pages but now supports building full web and mobile apps, real-time networking applications, command-line tools, and games.
- 🖥️ JavaScript code runs in browsers using JavaScript engines like SpiderMonkey (Firefox) and V8 (Chrome), but it can also run outside browsers using Node.js.
- 🔧 Node.js is a C++ program embedding the V8 JavaScript engine, allowing JavaScript to be used for server-side development.
- 🌍 JavaScript can execute in two main environments: browsers and Node.js, both providing a runtime environment for the code.
- 📜 ECMAScript is a specification that JavaScript adheres to. JavaScript is a language that conforms to ECMAScript standards.
- 📅 ECMAScript 2015 (ES6) introduced many new features for JavaScript, with yearly updates following since 2015 by the standards body ECMA.
- 🖱️ Developers can easily test JavaScript code in the browser's developer console by using commands like `console.log('Hello World')` and `alert('Yo')`.
Q & A
What is JavaScript?
-JavaScript is one of the most popular and widely used programming languages in the world. It's growing faster than any other programming language and is used by big companies like Netflix, Walmart, and PayPal for building internal applications.
What can you do with JavaScript?
-JavaScript can be used to build interactive web pages, full-blown web or mobile apps, real-time networking applications like chats and video streaming services, command-line tools, and even games.
Where does JavaScript code run?
-JavaScript code can run inside browsers or in Node.js. Browsers have JavaScript engines that execute the code, such as SpiderMonkey in Firefox and V8 in Chrome. Node.js, a C++ program that includes Google's V8 JavaScript engine, allows JavaScript code to run outside of browsers.
What is the difference between JavaScript and ECMAScript?
-ECMAScript is a specification, while JavaScript is a programming language that conforms to this specification. ECMAScript is defined by an organization called ECMA, which releases annual updates to the specification, such as ECMAScript 2015 (ES6).
Why is JavaScript referred to as a toy language by some developers?
-JavaScript was initially used only in browsers to build interactive web pages, leading some developers to consider it a toy language. However, due to community support and investments by companies like Facebook and Google, JavaScript's capabilities have expanded significantly.
How did Node.js change the use of JavaScript?
-Node.js, created by Ryan Dahl in 2009, embedded Chrome's V8 JavaScript engine inside a C++ program. This allowed JavaScript to run outside of browsers, enabling the development of backend applications for web and mobile apps using JavaScript.
What tools do you need to write JavaScript code?
-For a quick demo, you can use the JavaScript console in a browser's developer tools. For real-world applications, you would set up a development environment with tools like Node.js, a code editor, and possibly other frameworks and libraries depending on the project.
What are some examples of JavaScript engines in browsers?
-Examples of JavaScript engines in browsers include SpiderMonkey in Firefox and V8 in Chrome. These engines execute JavaScript code within the browser.
What does the 'console.log' function do in JavaScript?
-The 'console.log' function in JavaScript is used to print messages to the JavaScript console. It's commonly used for debugging purposes to check values and outputs of expressions.
What is the significance of ECMAScript 2015 (ES6)?
-ECMAScript 2015 (ES6) introduced many new features and improvements to JavaScript, such as arrow functions, classes, template literals, and more. It marked a significant update to the language and set the standard for future developments.
Outlines
🔍 Introduction to JavaScript
The speaker introduces the video as a 3-minute session addressing four common questions about JavaScript: What is JavaScript, what can you do with it, where does JavaScript code run, and what is the difference between JavaScript and ECMAScript. JavaScript is highlighted as a highly popular and rapidly growing programming language, used by major companies like Netflix, Walmart, and PayPal for internal applications. The potential for high salaries and diverse job roles (front-end, back-end, or full-stack developer) is also mentioned.
🛠️ Uses of JavaScript
JavaScript was historically used only in browsers to create interactive web pages, often dismissed as a 'toy language.' However, its capabilities have expanded significantly due to community support and investments from large companies like Facebook and Google. Nowadays, JavaScript can be used to build web and mobile apps, real-time networking applications like chats and video streaming services, command-line tools, and even games.
🌐 Where JavaScript Runs
JavaScript was initially designed to run exclusively in browsers, with each browser having its own JavaScript engine (e.g., SpiderMonkey in Firefox and V8 in Chrome). In 2009, Ryan Dahl created Node.js by embedding Chrome's V8 engine into a C++ program, allowing JavaScript to run outside of browsers. This means JavaScript can now be used for backend development as well. JavaScript code can run inside browsers or Node.js, both providing runtime environments for it.
📝 JavaScript vs. ECMAScript
ECMAScript is a specification, while JavaScript is a programming language that conforms to this specification. The organization responsible for ECMAScript, Ecma International, defines standards for the language. ECMAScript's first version was released in 1997, and since 2015, new versions have been released annually. ECMAScript 2015 (also known as ES6) introduced many new features to JavaScript.
🚀 JavaScript in Action
The speaker demonstrates how to write and execute basic JavaScript code in a browser. By opening Chrome, inspecting the page, and using the console tab, users can run JavaScript commands directly. Examples include logging 'Hello World' to the console, performing basic arithmetic, and displaying alerts. This segment serves as a quick demo, with a promise of more detailed instruction in subsequent lectures on setting up a development environment for JavaScript.
📚 Further Learning
The speaker, Mashar, briefly mentions that this tutorial is part of a comprehensive JavaScript course covering essential concepts and featuring numerous exercises and solutions. The course offers a certificate of completion, and interested viewers can find more information in the video description. The next section of the tutorial will continue to provide valuable content on JavaScript.
Mindmap
Keywords
💡JavaScript
💡Front-end developer
💡Back-end developer
💡Full stack developer
💡JavaScript engine
💡Node.js
💡ECMAScript
💡ES6
💡Console
💡Alert
Highlights
JavaScript is one of the most popular and widely used programming languages in the world right now.
Big companies like Netflix, Walmart, and PayPal build internal applications around JavaScript.
The average salary of a JavaScript developer in the United States is about $120,000 a year.
You can work as a front-end developer, back-end developer, or a full-stack developer with JavaScript knowledge.
JavaScript was initially used only in browsers to build interactive web pages.
JavaScript can now be used to build full-blown web or mobile apps, real-time networking applications, command-line tools, and even games.
JavaScript was originally designed to run only in browsers with engines like SpiderMonkey (Firefox) and V8 (Chrome).
Node.js, created by Ryan Dahl, allows JavaScript to run outside of browsers by embedding the V8 engine in a C++ program.
With Node.js, JavaScript can be used to build the backend for web and mobile applications.
JavaScript code can run inside a browser or in Node.js, which provide runtime environments for JavaScript code.
ECMAScript is a specification, while JavaScript is a programming language that conforms to this specification.
ECMAScript is managed by an organization called ECMA, which defines the standards for JavaScript.
The first version of ECMAScript was released in 1997, with annual releases starting from 2015.
ECMAScript 2015 (ES6) introduced many new features for JavaScript.
Using Chrome's developer tools, you can write and execute JavaScript code directly in the console.
This tutorial is part of a complete JavaScript course that includes exercises, solutions, and a certificate of completion.
Transcripts
[Music]
in the 3-minute introduction I'm going
to answer for frequently asked questions
about JavaScript
what is JavaScript what can you do with
it where does JavaScript code run and
what is the difference between
JavaScript and echo script so let's
start with the first question what is
JavaScript JavaScript is one of the most
popular and widely used programming
languages in the world right now it's
growing faster than any other
programming languages and big companies
like Netflix Walmart and PayPal build
internal applications around javascript
and here's the average salary of a
JavaScript developer in the United
States and it's only $2,000 a year so
it's a great opportunity to get a good
job out of learning JavaScript you can
work as a front-end developer or a
back-end developer for a full stack
developer who knows both the front end
and the back end now the second question
what can you do with JavaScript for a
long time
javascript was only used in browsers to
build interactive web pages some
developers refer to javascript as a toy
language but those days are gone because
of huge community support and
investments by large companies like
Facebook and Google these days you can
build full-blown web or mobile apps as
well as real time networking
applications like chats and video
streaming services command-line tools or
even games here's an example a third
question where does JavaScript code run
javascript was originally designed to
run only in browsers so every browser
has what we call a JavaScript engine
that can execute JavaScript code for
example the JavaScript engines in
firefox and chrome are SpiderMonkey and
v8 in 2009 a very clever engineer called
Ryan Dahl took the open-source
JavaScript engine in chrome and embedded
it inside a C++ program he called that
program node the node is a C++ program
that includes Google's v8 JavaScript
engine now with this we can run
JavaScript code out
of a browser so we can pass our
JavaScript code to node for execution
and this means with JavaScript we can
build the backend for our web and mobile
applications so in a nutshell JavaScript
code can be run inside of a browser or
in node browsers and node provide a
runtime environment for our JavaScript
code and finally the last question what
is the difference between JavaScript and
Eggman script well ECMO script is just a
specification javascript is a
programming language that confirms to
this specification so we have this
organization called a comma which is
responsible for defining standards they
take care of this Eggman script
specification the first version of
Eggman script was released in 1997 then
starting from 2015
ACMA has been working on annual releases
of a newest specification so in 2015
they released a kimono script 2015 which
is also called ECMO script version 6 or
es6 for short this specification defined
many new features for JavaScript alright
enough theory
let's see javascript in action so every
browser has a JavaScript engine and we
can easily write JavaScript code here
without any additional tools of course
this is not how we build real-world
applications but this is just for a
quick demo so open up Chrome right click
on an empty area and go to inspect now
this opens up chrome developer tools
here select the console tab this is our
JavaScript console and we can write any
valid JavaScript code here so type this
console dot log put a single code here
and then hello world another single code
to terminate close the parentheses and
add a semicolon at the end now as you go
through the course you're going to
understand exactly what all this means
for now don't worry about it so now I'll
press ENTER and you can see the hello
world message on the console we can also
write mathematical expressions here for
example two plus two we get four or we
can do something like this alert
practices single coat yo enter and
here's an alert in the next lecture I'm
going to talk about setting up your
development environment for writing
JavaScript code
well hello it's mahshar thank you for
watching my javascript tutorial I just
wanted to quickly let you know that this
tutorial is part of my complete
JavaScript course where you can learn
about all the essential concepts in
JavaScript the course is packed with
lots of exercises and solutions and by
the end of watching the course you will
also receive a certificate of completion
in case you're interested you can find a
link in the video description and if not
that's perfectly fine continue watching
as the next section is coming up
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