JavaScript, often referred to as JS is a high-level, interpreted programming language that adheres to the ECMAScript specification. It’s known for its dynamic, weakly typed, prototype-based, and multi-paradigm characteristics.
In the three-minute introduction, I’m going to answer four frequently asked questions about Learn JavaScript language.
- What is JavaScript?
- What can you do with it?
- Where does JavaScript code run?
And what is the difference between JavaScript and ECMAScript?
So, before starting the JavaScript you must learn about basic HTML roadmap and Basic CSS roadmap first.
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 language, and big companies like Netflix, Walmart, and PayPal build entire applications around JavaScript.
And here’s the average salary of a JavaScript developer in the United States. That is $72,000 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, a back-end developer, or 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.
The 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 V8 and Chrome SpiderMonkey. 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.
So, Node is a C++ program that includes Google’s V8 JavaScript engine. Now, with this, we can run JavaScript code outside 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 ECMAScript?
Well, ECMAScript is just a specification. JavaScript is a programming language that confirms this specification. So, we have this organization called ECMA, which is responsible for defining standards.
They take care of this ECMAScript specification.
The first version of ECMAScript was released in 1997. Then, starting from 2015, ECMA has been working on annual releases of a new specification.
In 2015, they released ECMAScript 2015, which is also called ECMAScript 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 different from how we build real world applications, but this is just for a quick demo.
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.
Type this console.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 press enter, and you can see the hello world message on the console. We can also write mathematical expressions here.
For example, 2 plus 2, we get 4.
Or we can do something like this. Alert, parentheses, single code, yo. Enter, and here’s an alert.
Learning Areas and Ideas
First you learn JavaScript and ES6 Section on freeCodeCamp.
Let’s go on the Next.
JavaScript Variables
In most cases, a JavaScript app has to handle data. To save and manipulate this data within the JavaScript code, we utilize variables. Essentially, a variable acts as a storage unit for a particular value.
Resources to learn fast
Go to the Next step.
Datatypes
In JavaScript, the concept of a “data type” signifies the variety of information that can be stored in a variable. The language offers seven fundamental or “primitive” data types: Number, BigInt, String, Boolean, Null, Undefined, and Symbol. On the other hand, Objects fall under the category of non-primitive data types.
Resources to go to the next step
- Learn JavaScript Data Types – CodeGuage
- Learn JavaScript data types and data structures
- Learn JavaScript Data Types
- Learn JavaScript Data Types
Data Structures
A data structure serves as a framework for arranging, handling, and storing data in a manner that enables quick and easy access and changes.
In JavaScript, there are both primitive (built-in) and non-primitive (customizable) data structures. Primitive data structures like arrays and objects are inherently available in the language, allowing for immediate implementation. On the other hand, non-primitive data structures are not included by default, requiring you to write specific code to use them.
Follow this resources
- Data structures
- Introduction to the Stack Data Structure
- Introduction to the Queue Data Structure
- Intro to Recursion: Anatomy of a Recursive Solution
- Binary Tree Algorithms for Technical Interviews – Full Course
- Graph Algorithms for Technical Interviews – Full Course
- Dynamic Programming – Learn to Solve Algorithmic Problems & Coding Challenges
Loops and Iterations
Loops and iterations are fundamental concepts in programming that allow for the repeated execution of a block of code. By using loops, you can perform the same operation multiple times without having to write the same lines of code over and over. This not only makes your code more efficient but also easier to read and maintain.
In JavaScript, there are several types of loops available, such as for, while, and do-while loops. Each type has its own use-cases and syntax, but they all serve the same basic purpose: to iterate over a block of code until a certain condition is met.
Check this resource
Functions
Functions serve the purpose of making code reusable. These are chunks of code set up to execute when called, typically designed to accomplish a specific task. For instance, you might have a function solely dedicated to calculating the sum of two or more numbers. Anytime you need to add numbers within your code, you can call this particular function as many times as needed.
Learn JavaScript functions resources
- Functions – MDN Docs
- JavaScript Functions – Programming with Mosh
- JavaScript Functions in Detail – CodeGuage
