I had the need to reverse a JavaScript array, and here is what I did.
Given an array list:
const list = [1, 2, 3, 4, 5]
The easiest and most intuitive way is to call the reverse() method of an array.
This method alters the original array, so I can declare list as a const, because I don't need to reassign the result of calling list.reverse() to it:
const list = [1, 2, 3, 4, 5]
list.reverse()
//list is [ 5, 4, 3, 2, 1 ]
You can pair this method with the spread operator to first copy the original array, and then reversing it, so the original array is left untouched:
const list = [1, 2, 3, 4, 5]
const reversedList = [...list].reverse()
//list is [ 1, 2, 3, 4, 5 ]
//reversedList is [ 5, 4, 3, 2, 1 ]
Another way is to use slice() without passing arguments:
const list = [1, 2, 3, 4, 5]
const reversedList = list.slice().reverse()
//list is [ 1, 2, 3, 4, 5 ]
//reversedList is [ 5, 4, 3, 2, 1 ]
but I find the spread operator more intuitive than slice().