在html表单中动态计算表中的行和列操作。

在HTML表单中动态计算表中的行和列操作可以通过JavaScript来实现。以下是一个示例代码，展示了如何动态添加和删除表格的行和列。

动态添加行：

<!DOCTYPE html>
<html>
<head>
<script>
function addRow() {
  var table = document.getElementById("myTable");
  var row = table.insertRow(table.rows.length);
  var cell1 = row.insertCell(0);
  var cell2 = row.insertCell(1);
  cell1.innerHTML = "New Row";
  cell2.innerHTML = "New Row";
}
</script>
</head>
<body>

<table id="myTable" border="1">
  <tr>
    <td>Row 1, Column 1</td>
    <td>Row 1, Column 2</td>
  </tr>
  <tr>
    <td>Row 2, Column 1</td>
    <td>Row 2, Column 2</td>
  </tr>
</table>
<br>

<button onclick="addRow()">Add Row</button>

</body>
</html>

动态添加列：

<!DOCTYPE html>
<html>
<head>
<script>
function addColumn() {
  var table = document.getElementById("myTable");
  for (var i = 0; i < table.rows.length; i++) {
    var cell = table.rows[i].insertCell(table.rows[i].cells.length);
    cell.innerHTML = "New Column";
  }
}
</script>
</head>
<body>

<table id="myTable" border="1">
  <tr>
    <td>Row 1, Column 1</td>
    <td>Row 1, Column 2</td>
  </tr>
  <tr>
    <td>Row 2, Column 1</td>
    <td>Row 2, Column 2</td>
  </tr>
</table>
<br>

<button onclick="addColumn()">Add Column</button>

</body>
</html>

动态删除行：

<!DOCTYPE html>
<html>
<head>
<script>
function deleteRow() {
  var table = document.getElementById("myTable");
  if (table.rows.length > 1) {
    table.deleteRow(table.rows.length - 1);
  }
}
</script>
</head>
<body>

<table id="myTable" border="1">
  <tr>
    <td>Row 1, Column 1</td>
    <td>Row 1, Column 2</td>
  </tr>
  <tr>
    <td>Row 2, Column 1</td>
    <td>Row 2, Column 2</td>
  </tr>
</table>
<br>

<button onclick="deleteRow()">Delete Row</button>

</body>
</html>

动态删除列：

<!DOCTYPE html>
<html>
<head>
<script>
function deleteColumn() {
  var table = document.getElementById("myTable");
  for (var i = 0; i < table.rows.length; i++) {
    if (table.rows[i].cells.length > 1) {
      table.rows[i].deleteCell(table.rows[i].cells.length - 1);
    }
  }
}
</script>
</head>
<body>

<table id="myTable" border="1">
  <tr>
    <td>Row 1, Column 1</td>
    <td>Row 1, Column 2</td>
  </tr>
  <tr>
    <td>Row 2, Column 1</td>
    <td>Row 2, Column 2</td>
  </tr>
</table>
<br>

<button onclick="deleteColumn()">Delete Column</button>

</body>
</html>

这些示例代码演示了如何通过JavaScript在HTML表单中动态计算表中的行和列操作。你可以根据实际需求进行修改和扩展。