单击按钮时对简单表进行排序

<table id="myTable">
  <tr>
    <th onclick="sortTable(0)">Name</th>
    <th onclick="sortTable(1)">Age</th>
    <th onclick="sortTable(2)">Country</th>
  </tr>
  <tr>
    <td>John</td>
    <td>25</td>
    <td>USA</td>
  </tr>
  <tr>
    <td>Mike</td>
    <td>30</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Lisa</td>
    <td>20</td>
    <td>UK</td>
  </tr>
</table>

<button onclick="sortTable(0)">Sort by Name</button>
<button onclick="sortTable(1)">Sort by Age</button>
<button onclick="sortTable(2)">Sort by Country</button>

function sortTable(columnIndex) {
  var table, rows, switching, i, x, y, shouldSwitch;
  table = document.getElementById("myTable");
  switching = true;
  while (switching) {
    switching = false;
    rows = table.rows;
    for (i = 1; i < (rows.length - 1); i++) {
      shouldSwitch = false;
      x = rows[i].getElementsByTagName("td")[columnIndex];
      y = rows[i + 1].getElementsByTagName("td")[columnIndex];
      if (x.innerHTML.toLowerCase() > y.innerHTML.toLowerCase()) {
        shouldSwitch = true;
        break;
      }
    }
    if (shouldSwitch) {
      rows[i].parentNode.insertBefore(rows[i + 1], rows[i]);
      switching = true;
    }
  }
}