<p>点击按钮按字母列表排序:</p>

<button onclick="sortList()">排序</button>

<ul id="id01">

  <li>Oslo</li>

  <li>Stockholm</li>

  <li>Helsinki</li>

  <li>Berlin</li>

  <li>Rome</li>

  <li>Madrid</li>

</ul>

function sortList() {

  var list, i, switching, b, shouldSwitch;

  list = document.getElementById("id01");

  switching = true;

  /*Make a loop that will continue until

  no switching has been done:*/

  while (switching) {

    //start by saying: no switching is done:

    switching = false;

    b = list.getElementsByTagName("LI");

    //Loop through all list items:

    for (i = 0; i < (b.length - 1); i++) {

      //start by saying there should be no switching:

      shouldSwitch = false;

      /*check if the next item should

      switch place with the current item:*/

      if (b[i].innerHTML.toLowerCase() > b[i + 1].innerHTML.toLowerCase()) {

        /*if next item is alphabetically lower than current item,

        mark as a switch and break the loop:*/

        shouldSwitch= true;

        break;

      }

    }

    if (shouldSwitch) {

      /*If a switch has been marked, make the switch

      and mark the switch as done:*/

      b[i].parentNode.insertBefore(b[i + 1], b[i]);

      switching = true;

    }

  }

}