Given two sorted arrays, A and B, where A has a large enough buffer at the end to hold B. Write a method to merge B into A in sorted order.

mergeTwoSortedArray

var mergeTwoSortedArray = function(array1, array2){
  var array1IndexEnd = array1.length - array2.length - 1;
  var arrayExtraIndexEnd = array1.length - 1;
  var array2IndexEnd = array2.length - 1;
    
  while( array2IndexEnd >= 0){
    if ( array1[array1IndexEnd] > array2[array2IndexEnd]){
        array1[arrayExtraIndexEnd] = array1[array1IndexEnd];
        arrayExtraIndexEnd--;
        array1IndexEnd--
    } else {
        array1[arrayExtraIndexEnd] = array2[array2IndexEnd];
        arrayExtraIndexEnd--;
        array2IndexEnd--;
    }
  }

  return array1;    
}

// var result = mergeTwoSortedArray([2, 4, 5, 26, 92, '', '', '', ''], [6, 7, 8, 8, 8, 9]);
// console.log(result);