rightRotationArray

function rightRotation(arr,rotation){
    rotation %= arr.length;

  while(rotation > 0){
    let lastEl = arr[arr.length-1];

    for(let i = arr.length -1; i > 0;i--){
        arr[i] = arr[i - 1];
    }

    arr[0] = lastEl;
    rotation--;
  }

  console.log(arr.join(', '));
}
rightRotation([1,2,3,4],3);