Shell Sort with Javascript

Shell_sort.js

/*
Best Case:N
Average Case:n*(logn)^2 OR (n)^(1.5)
Worst Case:(n)^(1.5)

*/
(function(){
  let comparison=0;
  let arr2=[28, 31, 43, 97, 49, 11, 33, 71, 41, 80, 86, 38, 53, 54, 7, 67, 96, 52, 29, 25, 56, 77, 73, 42, 62, 84, 21, 68, 2, 44, 9, 94, 66, 78, 6, 57, 20, 89, 1, 55, 65, 85, 51, 23, 70, 32, 12, 27, 18, 90, 4, 82, 5, 35, 58, 69, 22, 83, 37, 61, 79, 34, 81, 30, 72, 95, 91, 48, 88, 46, 3, 26, 60, 39, 17, 24, 74, 99, 10, 16, 87, 98, 76, 13, 36, 45, 59, 100, 50, 93, 19, 75, 92, 40, 8, 47, 14, 15, 63, 64];
  let arr=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100];

  function Shell_sort(array){
  let i, j, increment, temp;

   var start = Date.now();
  increment = 3;
  while (increment > 0)
  {
    for (i=0; i < array.length; i++)
    {
      j = i;
      temp = array[i];
          comparison++;
          let comparison2=0;
      while ((j >= increment) && (array[j-increment] > temp))
      {
          comparison++
        array[j] = array[j - increment];
        j = j - increment;
      }
      
      array[j] = temp;
    }
    if (Math.floor(increment/2) !== 0)
      increment = increment/2;
    else if (increment == 1)
      increment = 0;
    else
      increment = 1;
  }
   var end = Date.now();
   var elapsed = end - start; 
   console.log("Elapsed Time:"+elapsed);
    console.log("Total comparison:"+comparison);
    comparison=0;
    return array;
  }
Shell_sort(arr2);//Total comparison:1239

  console.log(Shell_sort(arr));
  
})();