Frontend Interview Question | What are Pure Functions? | SideEffects | Javascript Interview

Hello Everyone
In this session, we will learn about Pure Functions in Javascript and this is one of the asked question in Interview .
What are Pure Functions?
Function that produces the same output for the same input. It means it returns the same result when you pass the same arguments. A pure function shouldn't have any side effects to change the expected output
We need to make sure functions are,
Predictable: It produces a predictable output for the same inputs.
Readable: Anyone reading the function as a standalone unit can understand its purpose completely.
Reusable: Can reuse the function at multiple places of the source code without altering its and the caller's behavior.
Testable: We can test it as an independent unit.
What is SideEffect ?
Any operation that is not directly related to the final output of the function is called a Side Effect
A few more classic cases of the side effects are,
1)Mutating(changing) the input itself.
2) Querying/Updating DOM
3 )Logging(even in the console)
4) Making an XHR/fetch call.
Check another important interview Question
• Frontend Interview Que...
Check video on Recursion
• What is Recursion | Ja...
Support my channel by liking and sharing my videos so that I can reach to wider audience. Please share it in your network 🙏
Connect with me on social platform:
Facebook: / angularjs4beginners
LinkedIn: / nisha-singla-82407aa0
Instagram : / nishasingla05
Twitter: / nishasingla05
For more such interesting videos, please subscribe to my channel and stay connected.

[@buntykhipal5103]

this video helped me a lot to learn difference between pure and impure function
thank for making video

[@gyanendra_chaubey]

Your questions are awesome and you are doing great job. Is it possible for you to add more FE questions especially tricky ones like the one (async + settimeout + promises one). Anyways thank's for what ever you have posted till date.

[@RahulKumar-ew1qw]

Great explanation. Ms

[@krishtechhq]

Nice !

[@NishaSingla]

Thank you 😊

[@miw879]

very nicely explained :)

[@NishaSingla]

Thank you 😊

[@rajesh.geesala7565]

Thanks

[@BrijeshSingh-dp1ku]

Hi Nisha, thanks for sharing.. where you work?

[@NishaSingla]

😀😀