Note: This feature is available in Web Workers.
The open event is fired when a connection with a WebSocket is opened.
Use the event name in methods like addEventListener(), or set an event handler property.
addEventListener("open", (event) => { })
onopen = (event) => { }A generic Event.
// Create WebSocket connection.
const socket = new WebSocket("ws://localhost:8080");
// Connection opened
socket.addEventListener("open", (event) => {
socket.send("Hello Server!");
});