Bubble Sort

Explanation

1. Outer Loop (for loop):

   • This loop runs from the beginning of the array to the end.

   • The variable start represents the current pass through the array.

   • At the beginning of each pass, swapped is set to false.

2. Inner Loop (for loop):

   • This loop iterates over the array elements from the beginning to the last unsorted element.

   • curr represents the current element being compared.

   • The condition curr < end - start - 1 ensures that the loop only goes up to the last unsorted element, reducing the number of comparisons needed in each pass.

3. Comparison and Swapping:

   • if (arr[curr] > arr[curr + 1]) checks if the current element is greater than the next element.

   • If true, the elements are swapped using array destructuring: [arr[curr], arr[curr + 1]] = [arr[curr + 1], arr[curr]].

   • After a swap, swapped is set to true indicating that a swap has occurred during this pass.

4. Early Exit Optimization:

   • if (!swapped) break; checks if no elements were swapped during the current pass.

   • If swapped is still false, the array is already sorted, and the loop breaks early, improving efficiency by avoiding unnecessary passes.

5. Return Sorted Array:

   • After the sorting is complete, the function returns the sorted array.

Code

function bubbleSort(arr) {
  const end = arr.length;
  let swapped;

  for (let start = 0; start < end; start++) {
    swapped = false;

    for (let curr = 0; curr < end - start - 1; curr++) {
      if (arr[curr] > arr[curr + 1]) {
        [arr[curr], arr[curr + 1]] = [arr[curr + 1], arr[curr]];
        swapped = true;
      }
    }

    if (!swapped) break;
  }

  return arr;
}

console.log(bubbleSort([-2, 45, 0, 11, -9])); // [ -9, -2, 0, 11, 45 ]