Time to play with reduce() π₯³
I will try some functions with reduce() to deepen my understanding about reduce()
Array.prototype.reduce() - JavaScript | MDN
Flatten an array of arrays
To flat single level array
!Deep level flatten is not applicable with this function
=> The alternative is Array.prototype.flat() - JavaScript | MDN (Thanks @jcubic for your comment π)
Play it by yourself

Top comments (2)
There is Array.prorotype.flat() that do the same and more because it can do nested arrays of any level.
Excellent point!
I have added the information π
And I think if you want to flatten an array, using
flat()is more intuitive and readable than doing it withreduce().Anyway, thanks for your comment!