const arr =[1,2,3,4,5,6,7];
function rotate(arr,k){
let length = arr.length;
if(!k || !length) return arr;
for(let i=0;i<k;i++){
const n = arr.pop();
if(n){
arr.unshift(n);
}
}
return arr;
}
// console.log(rotate(arr,3));
function rotate2(arr,k){
let length = arr.length;
if(!k || !length) return arr;
const arr1 = arr.slice(-k);
const arr2 = arr.slice(0,length-k);
return arr1.concat(arr2)
}
console.log(rotate2(arr,3));