DEV Community

Cover image for Understanding Javascript Closures (Without Breaking a Sweat!)
Sultan Akhter
Sultan Akhter

Posted on

Understanding Javascript Closures (Without Breaking a Sweat!)

JavaScript is full of fascinating concepts, but few are as enchanting (and sometimes perplexing) as closures. If you’ve ever scratched your head wondering what closures are, you're in the right place. By the end of this two-minute read, you'll be able to dazzle your friends with your newfound knowledge. Ready? Let’s dive in!

What Exactly is a Closure?

In JavaScript, a closure is like a backpack. Imagine a function packing its variables and taking them along wherever it goes, even after the outer function has finished executing. This ability to remember and access its lexical scope is what makes a closure.

Why Should You Care About Closures?

Closures are everywhere in JavaScript. They are crucial for creating powerful and efficient code, especially when dealing with asynchronous operations, callbacks, and functional programming. Mastering closures can elevate your JavaScript skills from “meh” to “wow!”

The Closure Magic Show

Let’s break it down with a simple example:

Image description
Here’s what’s happening:

  1. Outer Function: 'outerFunction' defines a variable 'outerVariable' and an 'innerFunction'.

  2. Inner Function: 'innerFunction' has access to 'outerVariable' even after 'outerFunction' has executed.

  3. Closure in Action: When 'myClosure' is called, it remembers the environment in which it was created, logging "I’m the outer variable!".

Common Uses for Closures

1. Data Privacy:

Closures can help keep variables private and protect them from the outside world. Think of them as JavaScript’s version of a “Do Not Disturb” sign.

Image description

2. Creating Factories:

Closures are perfect for factory functions, where you need to create multiple instances of a function with their own private state.

Image description

Conclusion

Closures might sound like magic, but they are a fundamental part of JavaScript that can make your code more efficient and powerful. Remember, a closure is simply a function bundled together with its surrounding state (the lexical environment). So, next time you see a closure in action, give yourself a pat on the back – you’ve just witnessed some JavaScript wizardry!

Happy coding, and may your closures always be tight!

If you want to learn/revise about the basics of Javascript, follow me and checkout some other articles related to the basic concept of Javascript.

Top comments (22)

Collapse
 
wizard798 profile image
Wizard

Nice explanation, nicely explained everything

Collapse
 
i-sultan0 profile image
Sultan Akhter

I'm delighted you liked it.

Collapse
 
wilmela profile image
Wilmela

Very simple and clear.
Thanks javascript wizard. Lol

Collapse
 
i-sultan0 profile image
Sultan Akhter

Thanks! always here to assist you.

Collapse
 
yourakshaw profile image
Ayush Kumar Shaw

Quite a nice writeup Sultan! You very beautifully explained the critical JavaScript concept of closures. Thanks. I had fun reading it. 🤗

Collapse
 
i-sultan0 profile image
Sultan Akhter

Glad you like it.

Collapse
 
adamjamiu profile image
Adam Jamiu • Edited

Concised and informative. Thanks lad 👍

Collapse
 
i-sultan0 profile image
Sultan Akhter

I am glad you liked it.

Collapse
 
tanmoys95268896 profile image
Tanmoy Sinha

Awesome Content!

Collapse
 
i-sultan0 profile image
Sultan Akhter

Thanks.

Collapse
 
ghufran_baig_c46f561390d0 profile image
Ghufran Baig

Very nice and concise writeup add huge clarity with simple examples. Thank you

Collapse
 
i-sultan0 profile image
Sultan Akhter

I'm glad it resonated with you.

Collapse
 
benjamin_benkert_eec40f3b profile image
Benjamin Benkert

Well that was simple and easy to understand. Thanks!

Collapse
 
i-sultan0 profile image
Sultan Akhter

It's great to hear you liked it

Collapse
 
it-flashcards profile image
IT Flashcards

That was well explained. Every beginner JS programmer should have no problem understanding what closures are. 👍

Collapse
 
i-sultan0 profile image
Sultan Akhter

It's wonderful to know you liked it.

Collapse
 
andrew-saeed profile image
Andrew Saeed

Well explained! Nice work!

Collapse
 
i-sultan0 profile image
Sultan Akhter

Thanks.

Collapse
 
cleverakanimoh profile image
Clever AKANIMOH

Nice article ❤️👍

Collapse
 
i-sultan0 profile image
Sultan Akhter

Thanks.

Collapse
 
prakash_pandey_051277 profile image
Prakash Pandey

First time seen such a simple explanation of closures... Keep on trucking Sultan 🔥

Collapse
 
i-sultan0 profile image
Sultan Akhter

I'm pleased to hear you found it enjoyable.