<p>源数据：[10, -1, 20, 30, 0, 40, 1, 100]</p>
<p>排序：<span id="j-arr"></span></p>

// 找出数组中最小的数字
function findSmallest (arr) {
  let minValue = arr[0]
  let minIndex = 0

  for (let i in arr) {
    let item = arr[i]
    if (item >= minValue) { continue }
    minIndex = i
    minValue = item
  }

  return minIndex
}

// 对数字进行排序
function selectionSort (arr) {
  let len = arr.length
  let newArr = []
  for (let i = 0; i < len; i++) {
    let minIndex = findSmallest(arr)
    newArr.push(arr[minIndex])
    arr.splice(minIndex, 1)
  }

  return newArr
}

document.getElementById('j-arr').innerText = selectionSort([10, -1, 20, 30, 0, 40, 1, 100])