Reversal algorithm example

Array.js

// sample array
let samparr = [1,2,3,4,5];

// step 1 -> reverse d elements.
let samparr = [2,1,3,4,5];

// step 2 -> reverse n-d elements. Here n=5 and d=2 so (n-d) = (5-2=3)
let samparr = [2,1,5,4,3];

// step 3 -> reverse n elements. This gives the rotated array.
let samparr = [3,4,5,1,2]