HTMLTableSectionElement: insertRow() method

The insertRow() method of the HTMLTableSectionElement interface inserts a new row (<tr>) in the given table sectioning element (<thead>, <tfoot>, or <tbody>), then returns a reference to this new row.

[!NOTE] insertRow() inserts the row directly into the section. The row does not need to be appended separately as would be the case if createElement() had been used to create the new <tr> element.

Syntax

insertRow()
insertRow(index)

Parameters

• index Optional
  • : The row index of the new row. If index is -1 or equal to the number of rows, the row is appended as the last row. If index is omitted it defaults to -1.

Return value

An HTMLTableRowElement that references the new row.

Exceptions

• IndexSizeError DOMException
  • : Thrown if index is greater than the number of rows, or smaller than -1.

Examples

In this example, two buttons allow you to add and remove rows from the table body section; it also updates an <output> element with the number of rows currently in the table.

HTML

<table>
  <thead>
    <tr>
      <th>Col 1</th>
      <th>Col 2</th>
      <th>Col 3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>X</td>
      <td>Y</td>
      <td>Z</td>
    </tr>
  </tbody>
</table>
<button id="add">Add a row</button>
<button id="remove">Remove last row</button>
<div>This table's body has <output>1</output> row(s).</div>

table {
  border-collapse: collapse;
}

th,
td {
  border: 1px solid black;
}

button {
  margin: 1em 1em 1em 0;
}

JavaScript

// Obtain relevant interface elements
const bodySection = document.querySelectorAll("tbody")[0];
const rows = bodySection.rows; // The collection is live, therefore always up-to-date
const rowNumberDisplay = document.querySelectorAll("output")[0];

const addButton = document.getElementById("add");
const removeButton = document.getElementById("remove");

function updateRowNumber() {
  rowNumberDisplay.textContent = rows.length;
}

addButton.addEventListener("click", () => {
  // Add a new row at the end of the body
  const newRow = bodySection.insertRow();

  // Add cells inside the new row
  ["A", "B", "C"].forEach(
    (elt) => (newRow.insertCell().textContent = `${elt}${rows.length}`),
  );

  // Update the row counter
  updateRowNumber();
});

removeButton.addEventListener("click", () => {
  // Delete the row from the body
  bodySection.deleteRow(-1);

  // Update the row counter
  updateRowNumber();
});

Result

Specifications

Browser compatibility

See also

• insertCell()
• insertRow()