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How JS works behind the scenes?

tanishparashar on September 18, 2024

How JavaScript Works JavaScript operates in a single-threaded environment, meaning it executes one task at a time. It handles the execut...
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George WL • Edited

This was great, only minor quibble, I think it could make the keywords such as this stand out if wrapped in codeblocks (``)

So refreshing to see articles of high quality instead of all the listicles that other folks are spamming

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tanishparashar

Thankyou @georgewl.
Positive Criticism is much-needed as i am just a fresher and i wanna keep growing ✨️.

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Valentina

Great description of how JavaScript works. I'm curious how JavaScript manages asynchronous activities while being single-threaded. Could you explain how the Event Loop and Web APIs work together with the Call Stack in your upcoming post? thanks

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Hamza Pasking Akhtar • Edited

Yeah that would be a great thing to learn.
One topic is "Context Switching"
The other as you mentioned is Web API's which kinda gives you the illusion that JS is multi threaded despite being single threaded.

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tanishparashar • Edited

That's really motivating for me, i will make to sure explain it through code snippets and diagrams 😊.
Thankyou @vale58ntina

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Hitesh Kushwaha • Edited

There is a callback queue and a microtask queue following FCFS basis.
We can get asynchronous behaviour by either using async await or by using setTimeout/Interval.
Now when we use setTimeout/Intervals the corresponding code is pushed into callback queue
and when we use Async its pushed into microTask queue.

The event loop continuously checks if call stack is empty
If its empty then the first item from microTask queue is poped and placed in call stack for execution.
If microTask queue is empty then it checks for callback queue.

Hence async code block will always take priority in execution when compared to setTimeout/Interval.

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Ritesh Pawar

Really informative!!

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Vladislav Voronin

but so little

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tanishparashar

I never really thought anyone would read this so i didn't put much efforts, I will go all out next time!!

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Jenna • Edited

@tanishparashar ,

If you plan to write more about the topic you may want to create a series :-)

Happy writing ✍️

Best practices for writing on DEV:

dev.to/sloan/series/22620

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Nishanthan K

Great and well groomed explanation!

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tanishparashar

Thankyou So much

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Suhani Acharya

So informative, keep going ✊🏻

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tanishparashar

dev.to/tanishparashar/javascript-a...

The next part of this post is here!!
Do check it out

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Mykhailo Toporkov 🇺🇦

I would also recommend to read You-Dont-Know-JS series.

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tanishparashar

Sure!!

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Codelab

Hi there. as a mern stack developer, i launched my first web. Feel free to submit your feedback if it needs improving
codelabs.uz/

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tanishparashar

which component library did you use?

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Kamlesh Gupta

That's exciting

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Sunil khadka

I think including event loop can add great depth to this concept

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tanishparashar
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Subrajeet Maharana

Great and concise.

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Rodgers Nyangweso

concise piece

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Mashruf Ehsan

Nice article!

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Goodness Isaac

I don't seem to understand so much of this since i am new to JS, but with this i think i want to know more

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Rajeev Kumar

You write so well, but still, it does not look complete. Together, we can write much more about this topic. So, Let's collaborate!

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Sheraz Manzoor

Too much short, ho javascript works behind the scenes is a field in itself, it requires a long content.. Anyways good try. Keep it up boy

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Victorious Adelakun

Thank you

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good-gis

Easy to understand, well done ✨

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