MessageEvent: ports property

{{APIRef("HTML DOM")}}{{AvailableInWorkers}}

The ports read-only property of the {{domxref("MessageEvent")}} interface is an array of {{domxref("MessagePort")}} objects containing all {{domxref("MessagePort")}} objects sent with the message, in order.

Value

An array of {{domxref("MessagePort")}} objects.

Examples

onconnect = (e) => {
  const port = e.ports[0];

  port.addEventListener("message", (e) => {
    const workerResult = `Result: ${e.data[0] * e.data[1]}`;
    port.postMessage(workerResult);
  });

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

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("ExtendableMessageEvent")}} — similar to this interface but used in interfaces that needs to give more flexibility to authors.