DEV Community

Build a react-router clone from scratch

Thomas Cullen on March 10, 2021

React router is a package that I use in almost all of my projects. Not too long ago, Michael Jackson tweeted this. This made me curious as to how d...

Read full post

Harshil Parmar • Mar 11 '21

Great Effort !! brother 😁
I don't have much experience with useCallback,
Can you please explain this
How callback will detect that setLocation is changed !!
setLocation is just setter funciton right.

const handleHashChange = useCallback(() => {
    setLocation(window.location.pathname);
  }, [setLocation]);

Adnan Aslam • Mar 12 '21

useCallback() hook is used to capture the whole function just a way to optimize the performance like as memoisation.

useCallback() used in conjunction with useEffect() because it allows you to prevent the re-creation of a function.

I hope this information helps you in understanding the useCallback() hook in react.

@Cheers
adnanaslam

Harshil Parmar • Mar 12 '21

Thanks brother!!

Thomas Cullen • Mar 11 '21

Thanks for pointing this out! You are correct! We don't need to pass setLocation here in the callback dependencies as it won't change. Will update the post now, thank you!

Evgeny Artemov • Mar 10 '21

Great content and so few likes! That's because it's hard to understand in 5 mins :)

Thomas Cullen • Mar 10 '21

Thanks! Yeah definitely agree it's a lot for a quick read. I am thinking about also accompanying the post with a video tutorial which might be easier to digest.