JavaScript Basics – Data Types, Variables, Console & More!

#javascript #webdev #programming

Hey everyone!
Today in our JavaScript class, I learned some really important basic concepts that are super helpful for beginners like me. I’m sharing them here as a quick reference and recap for anyone starting their JavaScript journey.

JavaScript Data Types – Total 8

JavaScript has 8 different types of data:

String – Text (Example: "Hello")
Number – Numbers (Example: 10, 3.14)
BigInt – Very large numbers (Example: 12345678901234567890n)
Boolean – true or false
Undefined – A variable declared but not assigned any value
Null – Intentional empty value
Symbol – Unique identifiers
Object – Collection of key-value pairs

What is an Object?

An object is like a container that stores state and behavior.
In simple words, it’s a collection of properties (attributes) and methods (actions).

What are Attributes?

Attributes are the values or information stored inside an object.
For example, in the above person object, name and age are attributes.

** Variables in JavaScript – var, let, const**

In JavaScript, we use these to store data:

var – Function scoped, can be redeclared and reassigned
let – Block scoped, can be reassigned (not redeclared)
const – Block scoped, cannot be reassigned

Internal vs External JavaScript

You can use JavaScript in two ways:

Internal – Inside tags in the HTML file</li> <li> External – In a separate .js file and link it using <script src="file.js">

Printing Output – console.log()

We use console.log() to print results or debug our code.

Programming Language Types

There are two main types:

Statically Typed – Data types are fixed (like Java)
Dynamically Typed – Data types can change during runtime (like JavaScript)

Compiled vs Interpreted Languages

Compiled – Entire code is converted before running (e.g., C, C++)
Interpreted – Code is read and run line-by-line (e.g., JavaScript, Python)

Conclusion

It was a productive session today!
Learning about data types, variables, and how JavaScript works internally really helped me understand the basics better. These are the building blocks of JavaScript, and I’m excited to keep learning more!