ES6 bubblesort

bubblesort.js

const bubbleSort = arr => {
  if (!Array.isArray(arr)) {
    return -1
  }
  if (arr.length < 2) {
    return arr
  }

  for (let n = 0; n < arr.length; n++) {
    let swapped = false
    // no need to compare the last n element, it's already biggest ordered.
    // -1 means that only needs to traverse to the second to last, and compare the second to last and the last.
    for (let i = 0; i < arr.length - n - 1; i++) {
      if (arr[i] > arr[i + 1]) {
        // es6 style swap
        ;[arr[i], arr[i + 1]] = [arr[i + 1], arr[i]]
        swapped = true
      }
    }

    // if no swapping happen, the arr is already ordered.
    if (!swapped) {
      break
    }
  }

  return arr
}