MessageEvent.lastEventId

The lastEventId read-only property of the MessageEvent interface is a DOMString representing a unique ID for the event.

Syntax

var myId = messageEvent.lastEventId;

Value

A DOMString representing the ID.

Example

myWorker.onmessage = function(e) {
  result.textContent = e.data;
  console.log('Message received from worker');
  console.log(e.lastEventId);
};

Specifications

Specification
HTML Standard (HTML)
# dom-messageevent-lasteventid-dev

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
lastEventId
1
17
4
9
Yes
4
≤37
Yes
Yes
Yes
3
Yes

See also

  • ExtendableMessageEvent — similar to this interface but used in interfaces that needs to give more flexibility to authors.

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https://developer.mozilla.org/en-US/docs/Web/API/MessageEvent/lastEventId