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 Status Comment
HTML Living Standard
The definition of 'MessageEvent: lastEventId' in that specification.		 Living Standard

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
lastEventIdChrome Full support 1Edge Full support 17Firefox Full support 4IE Full support 9Opera Full support YesSafari Full support 4WebView Android Full support YesChrome Android Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support 3Samsung Internet Android Full support Yes

Legend

Full support
Full support

See also

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