Value

A string representing the returnValue of the dialog. Defaults to an empty string ("").

Examples

Checking the return value

The following example displays a button to open a dialog. The dialog asks the user if they want to accept a Terms of Service prompt.

The dialog contains "Accept" or "Decline" buttons: when the user clicks one of the buttons, the button's click handler closes the dialog, passing their choice into the close() function. This assigns the choice to the dialog's returnValue property.

In the dialog's close event handler, the example updates the main page's status text to record the returnValue.

If the user dismisses the dialog without clicking a button (for example, by pressing the Esc key), then the return value is not set.

HTML

html

<dialog id="dialog">
  <p>Do you agree to the Terms of Service (link)?</p>
  <button id="decline" value="declined">Decline</button>
  <button id="accept" value="accepted">Accept</button>
</dialog>
<button id="open">Open dialog</button>

<pre id="log"></pre>

#log {
  height: 170px;
  overflow: scroll;
  padding: 0.5rem;
  border: 1px solid black;
}

const logElement = document.getElementById("log");
function log(text) {
  logElement.innerText = `${logElement.innerText}${text}\n`;
  logElement.scrollTop = logElement.scrollHeight;
}

JavaScript

const dialog = document.getElementById("dialog");
const openButton = document.getElementById("open");
const declineButton = document.getElementById("decline");
const acceptButton = document.getElementById("accept");
openButton.addEventListener("click", () => {
  // Reset the return value on each open
  dialog.returnValue = "";
  updateReturnValue();
  // Show the dialog
  dialog.showModal();
});
function closeDialog(event) {
  const button = event.target;
  dialog.close(button.value);
}
function updateReturnValue() {
  log(`Return value: "${dialog.returnValue}"`);
}
declineButton.addEventListener("click", closeDialog);
acceptButton.addEventListener("click", closeDialog);
dialog.addEventListener("close", updateReturnValue);

Result

Click "Open Dialog", then choose the "Accept" or "Decline" buttons in the dialog, or dismiss the dialog by pressing the Esc key. Observe the different status updates.