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MessageEvent.ports

The ports read-only property of the MessageEvent interface is an array of MessagePort objects representing the ports associated with the channel the message is being sent through (where appropriate, e.g. in channel messaging or when sending a message to a shared worker).

Syntax

var myPorts = messageEvent.ports;

Value

An array of MessagePort objects.

Example

onconnect = function(e) {
  var port = e.ports[0];

  port.addEventListener('message', function(e) {
    var workerResult = 'Result: ' + (e.data[0] * e.data[1]);
    port.postMessage(workerResult);
  });

  port.start(); // Required when using addEventListener. Otherwise called implicitly by onmessage setter.
}

Specifications

Specification Status Comment
HTML Living Standard
The definition of 'ports' in that specification.
Living Standard Initial definition

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 1 Yes 4 9 ? 10
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support ? ? ? ? ? 3 ?

See also

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

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/MessageEvent/ports