Merge Sort

A divide and conquere technique for sorting

function merge(left, right)
{
  let arr = [];
  while (left.length && right.length)
  {
    if (left[0] < right[0])
    {
        arr.push(left.shift());
    }
    else
    {
        arr.push(right.shift());
    }
  }
  return [ ...arr, ...left, ...right ];
}

function mergeSort(array)
{
  const half = parseInt(array.length / 2);

  if(array.length < 2)
  {
    return array ;
  }

  const left = array.splice(0, half);
  return merge(mergeSort(left),mergeSort(array));
}