Bubble sort

Isabelle Viktoria Maciohsek · JavaScript, Algorithm, Array · Dec 29, 2020

Sorts an array of numbers, using the bubble sort algorithm.

  • Declare a variable, swapped, that indicates if any values were swapped during the current iteration.
  • Use the spread operator (...) to clone the original array, arr.
  • Use a for loop to iterate over the elements of the cloned array, terminating before the last element.
  • Use a nested for loop to iterate over the segment of the array between 0 and i, swapping any adjacent out of order elements and setting swapped to true.
  • If swapped is false after an iteration, no more changes are needed, so the cloned array is returned.
const bubbleSort = arr => {
  let swapped = false;
  const a = [...arr];
  for (let i = 1; i < a.length; i++) {
    swapped = false;
    for (let j = 0; j < a.length - i; j++) {
      if (a[j + 1] < a[j]) {
        [a[j], a[j + 1]] = [a[j + 1], a[j]];
        swapped = true;
      }
    }
    if (!swapped) return a;
  }
  return a;
};
bubbleSort([2, 1, 4, 3]); // [1, 2, 3, 4]

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