Bubble Sort

bubbleSort.js

/**
 * Helper function to swap items in array
 */
function swap(arr, firstIndex, secondIndex) {
  const temp = arr[firstIndex];
  arr[firstIndex] = arr[secondIndex];
  arr[secondIndex] = temp;
}

/**
 * For loop variant
 */
function bubbleSort(arr) {
  let len = arr.length;
  let i, j, stop;

  for (i = 0; i < len; i++){
    for (j = 0, stop = len - i; j < stop; j++){
      if (arr[j] > arr[j + 1]) swap(arr, j, j + 1);
    }
  }

  return arr;
}

/**
 * While loop variant
 */
function bubbleSort(arr) {
  let i = 0;
 
  while (i < arr.length) {
    if (arr[i] > arr[i + 1]) {
      swap(arr, i, i + 1);     
      i = 0;
    } else {
      i++;
    }
  }
  
  return arr;
}

console.log(bubbleSort([3, 2, 1, 3])); // [1, 2, 3, 3]